EARTH SCIENCE Lab Manual

EARTH SCIENCE

Lab Manual

UARM

Gaumani Gyanwali

University of Arkansas Rich Mountain

Cover by Shreetika Gyanwali

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Table of Contents

Experiment Page Number

Preface 3

1. Density of Rocks and Water 5

2. Salinity and Density 15

3. Latent Heat and Differential Heating… 25

4. Magma Viscosity and Isostasy of Mountains 33

5. Minerals and Rocks Part I 43

6. Minerals and Rocks Part II 53

7. Mineral Crystallization 61

8. Albedo Effect 69

9. Psychrometer Experiment 75

10. Coriolis Effect 85

11. Insolation Pattern 95

References 103

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Preface

Earth Science to me is a fascinating world of information, much of which is yet to be explored. It is this

unexplored part of the world which keeps the students imagining and the instructors exploring and

researching more to help students fulfill their goals. Last two spring semesters had been very rewarding in

terms of what I was able to learn in this natural field of science. As a preparation for the laboratory

portion of this course, I came across several laboratory manual textbooks that are intended to supplement

the lecture portion of the course. However, while implementing one selected laboratory manual in the labs

among many, I found that a major portion of the manual was designed to expose students again to many

core theoretical concepts. While it is good to revise and review the theoretical concepts and to give

students more opportunity to grasp the concept better, it is not so much appreciated if it has to be done in

a laboratory setting. Laboratory works should be more visual, experimental, hands-on, and hypothesis-

building.

Both I and my previous students of this course found that the available laboratory manuals were far from

meeting the above requirements. The student surveys about the course at the end of semester strongly

suggested that the available laboratory manuals were lacking the major portion of the laboratory

experience a science student would usually expect to do. I thank you all (students) for providing me a

genuine feedback for the course output and directly telling me what you would enjoy more! The more I

researched on preparing this laboratory manual, the more I understood you all about what exactly you

meant in your valuable feedbacks and surveys.

I believe that this Earth Science Lab Manual will provide simple and easy-to-follow instructions for

experimental procedures and help students understand basic principles in Earth Science. The step-wise

description of experimental procedures and corresponding data sheet pages are meant to provide students

with clear and detailed guidance to gain hands-on experimental learning experience. While some

experiments demand more safety precautions than others students are guided to follow all standard safety

precautions while using glassware, thermometers, hot objects, and gas burners etc. Use of safety goggles

is strictly required unless it is not required by the instructor to do so.

This lab manual is customized to the laboratory needs of Earth Science, PSC 104, at University of

Arkansas Rich Mountain (UARM) but can also be used by other college instructors who teach same or

similar courses in earth science, after receiving permission from the authorized personnel from UARM.

The experiments in this laboratory manual are designed for a two-hour long session once a week for a fall

or a spring semester. Same laboratory exercises can be implemented for twice-a-week schedules for

summer courses when needed.

Gaumani Gyanwali, PhD

University of Arkansas Rich Mountain

Mena, Arkansas 71953

©UARM, January 2017

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Experiment 1: Density of Rocks and Water

Objective: 1. To measure the density of various types of rocks in order to compare composition and

predict the formation process.

2. To measure the density of water at various temperatures.

Introduction

Density is a physical quantity which is the measure of compactness of particles or molecules. Density

explains how close or far apart the particles or components are to each other. The more tightly the

particles are arranged, the higher is the resulting density. You can take an example of cotton and a rock

for comparison. As you can observe, the cotton is very fluffy and light while a rock is very compact. As a

result, the density of the rock is very high as compared to cotton. Density is an intrinsic property, meaning

it is the property present in the objects depending on what they are made of.

Density also depends on other factors such as temperature. For example, in a warmer day the density of

air is low while in a colder day the density of air is high. Hotter temperature keeps the molecules of air

further apart and lowers the density and cooler temperature condenses the molecules closer and makes the

density lower.

Rocks are made of various minerals and particles. Depending on which material is the rock made of, its

density varies. If it is made of naturally harder materials or if it is more compactly arranged, its density is

high. If it is made of lighter materials or is less compactly organized, its density will be low. For example,

density of mainly iron-oxide rich minerals such as hematite is obviously high and density of silica-rich

minerals is low. Also, density of a metamorphic rock made from a sedimentary rock is high while density

of the parent sedimentary rock from which the metamorphic rock was made is low. Mainly, two factors

control the density of rocks – its mineral composition and its mode of formation.

We can calculate the density of a rock by using simple scientific techniques of finding its mass and its

volume first. Then the ratio of its mass to its volume gives its density. It means that the total quantity of

material (mass, in kilograms, grams, milligrams etc.) present in a unit volume (in m

3

, liter, cm

3

etc.) of a

substance gives its density. Density can be expressed in the form of formula as follows:

Density = Mass (kg)

Unit of Density = kg/m

3

Volume (m

3

)

After finding the density of the rocks we can roughly predict the possible mineral composition of the rock

by density comparison.

Like solids, liquids also have their own density. The liquid density also depends on its composition (the

type of molecules it has and their arrangement). Unlike solids whose density does not significantly change

over small range of temperature, liquids show density change even over small change in temperatures.

That is because the molecules of liquid are farther apart than solids and can be affected by temperature

changes easily.

Part A: Density of Rocks

Mass of the rock can be found by using the digital balance. You should tare the balance to zero before

you slowly put the rock on the pan.

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A rock is a solid whose dimensions are not regular. That means it does not have uniform length, width, or

height throughout. So to find its volume, we have to use an indirect method of finding the space it

occupies. If we dip a rock in water, it displaces water of equal volume to the volume the rock occupies

inside water. The volume of displaced water then gives the actual volume of the rock. This indirect

method of measuring volume of irregular solids such as a piece of rock is quite accurate indeed!

Figure 1.1: A rock has non-uniform dimensions

To find the volume of displaced water, we first measure the water in a container without putting the rock

(known as V

i

) and then measure the water level after putting the rock (known as V

f

). When we subtract

these two volumes we get the volume of the rock.

Volume of rock = V

f

- V

i

After we find the mass and the volume of the rocks we can calculate the density by dividing the mass by

the volume, using the above mentioned formula, density = mass/volume

Part B: Density of water at different temperatures

In water the molecules are closely packed and can slide past each other. This makes the mobility of

molecules easy and can easily be affected by temperature changes. The changes can be seen in terms of

density measurements at various temperatures. In this experiment we will measure the density of water at

three different temperatures: at room temperature, at 50-60

o

C, and at around the boiling temperature.

Measuring mass and the volume of water can be done at the same time using graduated cylinder. You

should first place the graduated cylinder on the balance and tare it to zero. When known volume of water

is added to the cylinder (you know it from the graduated scale on the cylinder), you can also read the

mass of the water you just added from the balance. Then use the formula of density to calculate the

density of water you used.

The formula is again, density = mass/volume

Materials Required

Different pieces of rocks, 100 mL graduated cylinder, 50 mL graduated cylinder, digital balance,

calculator, heating set-up (stand, wire gauze, ring clamp, Bunsen burner, lighter), 100 ml-beaker, beaker

tongs, heat gloves, thermometer.

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Procedure

Follow the given procedures for each part of the experiment in the numerical order given. Record all the

measurements in the data sheet and carry out proper calculations using appropriate formula.

Part A: Density of Rocks

1. Bring the provided rocks on your desk and record each rock’s physical appearance on the data

sheet.

2. Record the mass of each rock using the digital balance. First zero (tare) the balance and then

gently put the rock on the balance pan. Record the mass to three decimal places.

3. In a 100 ml graduated cylinder, place about half water and record the initial reading of water

level.

4. Place the rock into the cylinder carefully so that you do not splash any water. You can slide the

rock along the wall of the cylinder.

5. After the rock settles at the bottom, shake the cylinder so that any air bubbles attached to the rock

will escape. Record the level of water in the cylinder now.

6. The difference between these levels of water gives volume of water raised, which is same as the

volume of the rock submerged under water. Use appropriate units for each quantity measured.

7. Calculate the density of the rock using the mass and volume you just found by applying

appropriate formula. You must show the work of this calculation in the space provided in the data

sheet

Part B: Density of water at different temperatures

Room temperature water

1. Bring all requirements for a heating set up: Bunsen burner, wire gauge, ring clamp, stand, and a

lighter.

2. Bring a 100 mL beaker. Make sure it is clean and dry. Measure its mass using the digital balance,

zeroing it first, and record in the data sheet.

3. Bring a 50 mL graduated cylinder and fill it to 50 mL-mark with DI (deionized) water. Record the

actual volume of water taken as either exact 50 mL, or if it is not exact 50 mL, whichever is the

volume shown by the lines in the cylinder. It does not matter if it is slightly less than (not more

than) 50 mL but record the volume.

4. Place the water into the beaker. Measure its current temperature with a thermometer and record in

the data sheet.

5. Place all the water into the 100 mL-beaker and measure the mass of the beaker with water.

Record it.

6. Subtract the mass of the beaker from this water + beaker mass to get the mass of water only.

7. Now you can calculate the density of this water using appropriate formula.

50

o

C – 60

o

C water

1. Measure 50 mL DI water as above using a 50 mL-graduated cylinder and record the exact volume

taken. Again, it does not have to exact 50.0 mL but record whichever number you have.

2. Place this water in the 100 mL-beaker and set it up for heating on the wire gauge of the heating

set-up.

3. Light the burner outside of the set-up and bring it under the beaker. Use a medium to low flame.

Place the thermometer in the beaker. Caution: it may drop off the beaker if you leave it, so keep

holding it, being careful about not catching the fire.

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4. As the temperature reaches 55

o

C, first record the exact temperature in the data sheet and then

remove the beaker from the heating set-up using a beaker tong or a heat glove. Measure the mass

of this water and the beaker together. Record the mass.

5. Find the mass of the water only and calculate the density using appropriate formula.

Near-boiling water

1. Measure 50 mL DI water as above using a 50 mL-graduated cylinder and record the exact volume

taken. It has to be close to 50 mL but exact 50mL is not required.

2. Place this water in the 100 mL-beaker and set it up for heating on the wire gauge of the heating

set-up, as above

3. Use a high flame this time in the burner to heat the water. Low flame will take forever!

4. As the temperature reaches 95

o

C, first record the exact temperature in the data sheet and then

remove the beaker from the heating set-up using a beaker tong or a heat glove. Measure the mass

of this water and the beaker together. Record the mass.

5. Find the mass of the water only and calculate the density using appropriate formula.

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Experiment 1: Density of Rocks and Water

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is density? Write its formula.

Q2. Why the volume of rocks cannot be found using length, width, and height method?

Q3. An object A floats on water but another object B sinks in water. Which object has higher density?

Which object has density less than density of water?

Q4. Why is it important to measure the density of rocks?

Q5. If the unit of mass is gram and the unit of volume is cm

3

, what will be the unit of density?

Instructor’s approval____________________

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Date

Name

Lab Partner

Experiment 1: Density of Rocks and Water

Data Sheet

Part A: Density of Rocks

Write hypothesis: Simply based on your observation of the rocks, order the rocks from the

highest density to the lowest density. Give a brief explanation.

______________________________________________________________________________

_____________________________________________________________________________

Rock 1 Rock 2 Rock 3

Color of the rock ______________ ______________ ______________

Texture of the rock ______________ ______________ ______________

Mass of the rock ______________ ______________ ______________

Initial water level in the cylinder ______________ ______________ ______________

Final water level in the cylinder ______________ ______________ ______________

Volume of the rock ______________ ______________ ______________

Calculation for density of rocks (show work in the space provided below)

Rock 1 Rock 2 Rock 3

Density of the rocks from above calculation _______________________ (rock 1)

_______________________ (rock 2)

_______________________ (rock 3)

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Answer the following questions:

Q1. Was your hypothesis about the rock density proved? Reorder the rocks based on the calculated

density.

Q2. If you splashed water while placing the rock, how would it affect the density of the rock?

Q3. Why is density of rock important to measure?

Q4. How is density of rocks related to hardness?

Q5. Make a general conclusion from the observation of densities of rocks above.

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Part B: Density of water at different temperatures

Write hypothesis: Propose a hypothesis about the density of water at different temperatures,

will it decrease or increase with temperature? How drastically will it change with temperatures?

______________________________________________________________________________

Mass of the 100 mL-beaker, dry and clean ____________

Room Temp 50

o

C – 60

o

C 95

o

C – 100

o

C

Actual volume of water measured ______________ ______________ ______________

Actual temperature of water measured ______________ ______________ ______________

Mass of beaker + water ______________ ______________ ______________

Mass of water by subtraction ______________ ______________ ______________

Calculate the density of water below:

Room Temp 55

o

C – 60

o

C 95

o

C – 100

o

C

Calculated density of water from above _______________________ Room Temp

________________________ 55

o

C – 60

o

C

________________________ 95

o

C – 100

o

C

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Answer the following questions.

Q1. Was your hypothesis proved or disproved? Explain your observation with a scientific reasoning.

Q2. Make a general conclusion from your observation above

Q3. If you evaporated some of your water during the process of measuring the density, how will this

affect your result?

Q4. Is the water in the equatorial seas heavier or lighter than the polar seas? Justify your answer.

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Experiment 2: Salinity and Density

Objective: 1. To prepare saline solutions of different composition.

2. To measure and compare the density of the prepared solutions.

Introduction

Salinity is defined as the amount of dissolved salts in water. It is usually expressed in terms of parts per

thousand (ppt) i.e. parts of salt present per thousand parts water. For example, if salinity of the water

collected from an estuary is 45 ppt, the water has 45 grams of salt per 1000 grams of water (or it could be

45 kg salt per 1000 kg water). In seawater there are many dissolved salts but sodium chloride (table salt)

is the most abundant salt.

Solution is a uniform mixture of a solute (the one that gets dissolved, usually solid) and a solvent (the

dissolver, usually liquid). For example, in a sugar-water solution, the solute is sugar and the solvent is

water. However, to make a solution, it does not have to be always a liquid/solid combination, other

combinations can also make solution.

In a solution, solute is always the smaller fraction and solvent is a larger fraction. Being a larger fraction

of the solution, the solvent has the duty to dissolve the solute in order to make a proper solution. The

process of making a solution using a solute and a solvent is called dissolution.

Part A: Preparation of saline solutions

I this laboratory, we will prepare natural-like saline solutions using sodium chloride and water. Since

sodium chloride is the most common salt found in natural sea water, we will try to mimic nature by

preparing salt solutions of different concentrations using right amount of salt and water needed. We will

also learn to convert the grams of salt present in the solution into the parts per thousand using appropriate

conversions needed.

Care must be given in measuring right amount of salt and water to make proper solution. Also, the salt

must be properly dissolved to have the concentration needed for the solution. If the salt remains

undissolved, it will be counted in the mass but not in the solution, so the measurement of volume will be

wrong and the calculated density eventually becomes wrong.

Part B: Measurement of density of solutions

You have learned in pervious chapter (Experiment #1) to measure the mass and volume of the liquid at

the same time so that we can calculate the density of the solution. Here, you will follow exactly the same

procedure to measure the mass and the volume of the five solutions made in part A. You will need to

place the graduated cylinder on the digital balance pan and zero it. And add the specified amount of

solution into the cylinder to measure the mass. The volume can be read directly from the graduated scale

of the cylinder.

Once we know the mass and volume of the solution, we can use the same formula we used in previous

chapter for density of solutions, i.e. density = mass / volume

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Once you have computed the density of different solutions and the corresponding salinity, you will also

need to plot the graph in the given grid to find a correlation between the two. The graph will be used to

express the relationship between these two quantities to draw necessary conclusion.

Materials Required

Table salt, five 150-mL beakers, digital balance, five 25-mL graduated cylinders, scoop, five clean and

dry glass rods, disposable pipets.

Procedure

Follow the given procedure for each part of this experiment in the order given. Record all the

measurements in the data sheet and carry out proper calculations using appropriate formula.

Part A: Preparation of saline solutions

1. Obtain five 150-mL clean and dry beakers. If not all available, can use 100- or 50-mL beakers as

well, but use beakers of same size.

2. Label the beakers with a marker from numbers 1 through 5.

3. Place beaker #1 on the digital balance pan and zero it.

4. Add 0.2 g salt slowly and carefully to avoid spillage. If spilled, clean up your mess!

5. Add DI water with a dropper to make the total solution weigh 20 grams.

6. Stir the solution using a glass rod until the salt completely dissolves.

7. Repeat the process for beakers #2 through #5 but using 0.4 g, 0.6 g, 0.8 g and 1.0 g salt

respectively, and adding water in each one to make total mass 20 grams every time. Remember,

the water has to be added when the beaker is still on the balance pan until you read 20 grams as

the total mass on the scale, not outside of the scale.

8. Use separate stirring rods for each solution to avoid contamination.

Part B: measurement of density of solutions

1. Place a clean dry 25-mL graduated cylinder on the pan and tare it.

2. Add all the salt solution from beaker #1 into it. Record the mass of the salt solution.

3. Also record the exact volume of the solution in the cylinder to one decimal place.

4. Repeat the process for remaining four solutions and record the appropriate mass and volume of

the solutions in the data table.

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Experiment 2: Salinity and Density

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. Identify solute and solvent in the following solutions

a. 10.0 g salt and 50.0 g water solute = solvent =

b. 2.0 g salt and 3.0 g alcohol solute = solvent =

c. 10.0 g glycerol and 5.0 g methanol solute = solvent =

d. 1.0 g methanol and 0.5 g ethanol solute = solvent =

Q2. Why is salt present in oceans?

Q3. If a 50-gram solution has 2.0 g salt, what is the ppt (0/00) of the solution?

Q4. Why is it important to know the density of water with different amount of salt in it?

Q5. If you measured the mass and the volume of a solution without completely dissolving the salt, what

will be the effect in your density measurement?

Instructor’s approval____________________

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Date

Name

Lab Partner

Experiment 2: Salinity and Density

Data Sheet

Write hypothesis: Write the correlation of the salinity of water to its density. Would you expect

the increase or decrease of density with salinity will be uniform or non-uniform?

______________________________________________________________________________

_____________________________________________________________________________

Part A: Preparation of saline solutions

Solution #1: 0.2 g salt in 20 ml water

Actual grams of salt taken __________

Per 20-gram solution, amount salt present ___________

Per 100-gram solution, amount of salt present __________

Per 1000-gram solution, amount of salt present ________

0/00 (PPT) of the Solution #1 ___________

Solution #2: 0.4 g salt in 20 ml water

Actual grams of salt taken __________

Per 20-gram solution, amount salt present ___________

Per 100-gram solution, amount of salt present __________

Per 1000-gram solution, amount of salt present ________

0/00 (PPT) of the Solution #2 ___________

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Solution #3: 0.6 g salt in 20 ml water

Actual grams of salt taken __________

Per 20-gram solution, amount salt present ___________

Per 100-gram solution, amount of salt present __________

Per 1000-gram solution, amount of salt present ________

0/00 (PPT) of the Solution #3 ___________

Solution #4: 0.8 g salt in 20 ml water

Actual grams of salt taken __________

Per 20-gram solution, amount salt present ___________

Per 100-gram solution, amount of salt present __________

Per 1000-gram solution, amount of salt present ________

0/00 (PPT) of the Solution #4 ___________

Solution #5: 1.0 g salt in 20 ml water

Actual grams of salt taken __________

Per 20-gram solution, amount salt present ___________

Per 100-gram solution, amount of salt present __________

Per 1000-gram solution, amount of salt present ________

0/00 (PPT) of the Solution #5 ___________

Part B: measurement of density of solutions

Solution #1

Total mass of the solution __________

Total volume of the solution ___________

Density of the solution ___________

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Solution #2

Total mass of the solution __________

Total volume of the solution ___________

Density of the solution ___________

Solution #3

Total mass of the solution __________

Total volume of the solution ___________

Density of the solution ___________

Solution #4

Total mass of the solution __________

Total volume of the solution ___________

Density of the solution ___________

Solution #5

Total mass of the solution __________

Total volume of the solution ___________

Density of the solution ___________

In the following table copy the data for solutions #1 through #5 you calculated from above.

Solution

Salinity

Density

1

2

3

4

5

Now plot the salinity versus density curve for these solutions in the grid provided below. Use a colored

pen for the curve.

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10 20 30 40 50 60

Salinity (ppt)

Answer the following questions:

Q1. Was your hypothesis proved about density and salinity correlation? Explain briefly.

Q2. What are the possible sources of error in this experiment?

D

e

n

s

i

t

y

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Q3. In a sea there are two types of saline waters, one with salinity 35.60 ppt and another with 40.21 ppt.

which water will have higher density? Why?

Q4. Of the waters given in question 3, which water should make the lower layer in the sea? Why?

Q5. What direct conclusion could you draw from the graph you made above?

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Experiment 3: Latent Heat and Differential Heating of Land and Water

Objective: 1. To heat sand and water separately using the same source of heat for same time.

2. To plot curves for heating sand and water to compare the rates of heating of land and water.

Introduction

Latent heat is the heat given to or taken away form a substance in such a way that the temperature

change is not observed. In other words, even if heat is supplied to (or taken from) the substance, the

temperature remains the same.

To elaborate latent heat, let’s take an example of a burning candle. To convert the wax from solid to

liquid, we need to heat (i.e. supply heat to the wax). What happens as we heat wax for the first time? In

the beginning, the wax starts absorbing the supplied heat instead of increasing temperature. This absorbed

heat causes wax to change from solid to liquid, not increasing the temperature yet! This kind of heat used

to change the state of the substance rather than to change the temperature is called latent heat. After the

latent heat phase, the heat supplied is then used to increase the temperature. Latent heat also occurs during

liquid to gas phase change.

The phenomenon of latent heat is common in nature during melting of ice and vaporization of water. Ice

can change to water at 32

o

F (0

o

C) by absorbing heat from the surrounding but keeps the temperature

unchanged at 32

o

F. Formation of slippery sleet under icy road conditions is due to this nature of water.

Addition of salt to the icy roads decreases the melting temperature of ice so that ice starts melting at lower

temperatures than 32

o

F and the roads get cleared of ice easily. This is one good example of study of

science directly applied in solving problems.

In part A of this experiment, you will learn to record the latent heat phenomena for water at two stages of

change of state: one at ice to water conversion stage and another at water to vapor conversion stage. For

this you should start from the ice phase and gradually change to vapor phase over time. Since you will be

constantly supplying heat, it is assumed that the supplied heat is constantly absorbed by the contents of

the beaker. If temperature does not change even after supplying heat, this stage is known as latent heat

stage.

Heat absorbing capacity of different substances is different. This is based on the material of which the

substance is made. Land and water absorb heat very differently. Due to this difference in absorption of

heat we see several weather patterns coming in or going out from land to water and water to land i.e.

hydrosphere to geosphere heat interaction and geosphere to hydrosphere heat interaction.

In Part B of this experiment, you will see the difference between heat absorbing capacity of water and

land. Of all land components, sand (dessert) shows most significant heat absorption/loss phenomenon, so

we will use sand to represent the land mass for differential heat absorption experiment.

Materials Required

125 mL beaker, beaker tongs or heat glove, heating set up, ice, thermometer, sand, timer.

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Procedure

Part A: Latent heat

Follow the following procedure to record the data for heating ice-water.

1. Bring a clean 125-mL beaker and place on the digital balance. Add 90 grams of ice (better if

shaved). Add water to make the total mass 100 grams. Record the mass in the data sheet.

2. Immediately insert a thermometer.

3. Prepare a heating set up using stand, Bunsen burner, ring clamp, and a wire gauze.

4. Light the burner and start heating the ice. Set the timer on and record the initial constant

temperature of the ice-water in the data sheet. Keep recording the temperature every two minutes

until the water reaches to boiling and 10 more minutes (5 data points) even after boiling.

5. Stop heating by removing the burner (do not turn off the burner because you will need the same-

sized flame to keep the heat source constant for sand experiment, Part B).

6. Using a heat glove or beaker tongs, remove the beaker and throw the water into the sink. Clean

the beaker with running tap water and wipe it dry for Part B.

Part B: Land and water heating rate

Follow the following procedure to record the data for heating sand

1. Bring the 125-mL beaker you dried in Part A and place it on the digital balance. Add 100 g sand.

Record the mass in the data sheet.

2. Insert a thermometer and record the initial temperature.

3. Set the beaker for heating on the wire gauze and bring the burner in to start heating. Immediately

start the timer on.

4. Keep recording the temperature every two minutes until the temperature reaches to 100

o

C or total

of twenty data points are recorded, whichever is earlier.

5. Stop heating by turning off the burner this time. Let the beaker of sand cool for some time while

you plot your data points in the graph provided.

6. Using a heat glove or beaker tongs, remove the beaker and throw the sand into a designated

container. Clean the beaker and set it for drying.

27 | E a r t h S c i e n c e L a b M a n u a l

Experiment 3: Latent Heat and Differential Heating of Land and Water

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is latent heat?

Q2. Why does the candle melt at the beginning of its burning?

Q3. State two temperature conditions under which latent heat of ice/water/vapor system occurs.

Q4. Why do we put salts on icy roads?

Q5. On which factor does heat absorption by a matter depend?

Instructor’s approval____________________

28 | E a r t h S c i e n c e L a b M a n u a l

29 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 3: Latent Heat and Differential Heating of Land and Water

Data Sheet

Write hypothesis Part A: Around which temperatures do you think the latent heat event(s)

might occur while heating ice-water to boiling?

______________________________________________________________________________

Write hypothesis Part B: Which substance will have faster heating rate between water and

sand?

_____________________________________________________________________________

Part A: Latent heat

Mass of ice taken _______________

Mass of water added ______________

Total mass of ice-water ____________

Table for heating rate of ice water

Time

Temperature

Time

Temperature

0 min

30 | E a r t h S c i e n c e L a b M a n u a l

Part B: Land and water heating rate

Mass of sand taken ___________

Table for heating rate of sand

Time

Temperature

Time

Temperature

0 min

Answer the following questions.

Q1. What is the purpose of keeping the flame size same for both experiments?

Q2. Why is it important to keep the mass of water and sand same?

Q3. What difference did you observe from the collected data for heating rates of water and sand?

31 | E a r t h S c i e n c e L a b M a n u a l

Now Plot the graph of the heating rate of ice-water as well as heating rate of sand in the same graph sheet

given in the following page. Use different colors for ice-water and sand curves.

Time

T

e

m

p

e

r

a

t

u

r

e

32 | E a r t h S c i e n c e L a b M a n u a l

Answer the following questions.

Q1. Observe the curve in the graph for ice-water heating carefully. Find two temperature regions from the

graph where you find not a significant increase in temperature with time.

_________________ ________________

Q2. Was your hypothesis on Part A proved? Briefly explain.

Q3. From the graphical curve, explain your understanding about latent heat.

Q4. Explain what you found while comparing the heating curve for sand versus heating curve for water.

Q5. How the findings of this experiment are important in real-life situation?

33 | E a r t h S c i e n c e L a b M a n u a l

Experiment 4: Magma Viscosity and Isostasy of Mountains

Objective: 1. To study the viscosity of liquids by drop-count method

2. To study the correlation between mountain height and the mountain root

Introduction

Part A: Viscosity

Section 6.2 in the textbook (Page 142 – 144) explains about the effect of magma viscosity in determining

the nature of volcano and its nature of explosion. In the same section we also study the effect of

temperature on viscosity of magma. The main objective of this experiment is to give you first-hand

experience with the materials of different viscosity and their flow in a controlled passage. In this

experiment, we will also see the effect of temperature on the substance’s viscosity.

Viscosity is resistance to flow. You have seen that liquids flow. Some liquids flow fast and some flow

slowly. A syrup relatively flows slower than water. What does this mean about its viscosity? If substance

A flows at a slower rate than substance B, then the viscosity of A is higher than viscosity of B. This means

that A has more resistance to flow. In order to check the viscosity or flow rates of two substances, care

should be taken in that the both substances are made to flow through same, or at least, similar passages.

This minimizes the effect caused by the passage itself to the material.

In this experiment, in order to avoid discrepancy, we will use similar two pipets with similar narrow

capillary tubes and allow our test materials to flow through it. The total number of drops made by that

material while passing through the similar passage will give the relative rate of flow. The higher is the

number of drops, the faster has the material flown and lower is its viscosity. On the same token, the lower

is the number of drops, slower has the material flown and higher is the viscosity.

Viscosity also depends on temperature (Page 143, section 6.2 textbook). When temperature increases,

the mobility of the molecules increases and, as a result, the flow increases. What does this mean in terms

of viscosity? It means that the viscosity decreases.

Part B: Height of Mountains and Isostasy

Refer to Section 6.7 in our textbook (page 166 – 167) for this part of the experiment. Density of the

materials of which a mountain is made determines how tall a mountain can be and how deep it can go

under the crust. This analogy and relationship between mountain height and the density can be

demonstrated in laboratory experiments using wooden blocks and water. As you have seen in previous

experiments that if a material is compactly built, its density is high and loosely packed materials have less

density. And if the density of the material is high, its weight is also high. That means it pushes (forces

itself) downward with a greater gravitational force. This concept directly applies to the mountain height

and their push on the Earth’s crust in order to maintain that height.

Isostasy is the balance between the topography of the Earth’s crust and its thickness and the density of the

rocks it is standing on. In order to maintain this isostasy, the removal or addition of materials on the

Earth’s crust has to bring changes in the downward forces and arrangement of the rocks so that the same

balance is maintained even in the new scenario. For example, if you add some material on the top of a

mountain, the mountain becomes heavier now and its root now increases in size. That means, isostasy

compensates for added material by making the submerged root bigger thereby adding only slightly the

34 | E a r t h S c i e n c e L a b M a n u a l

total height of the mountain. Similarly, if material is removed by erosion, the root decreases in height,

and again the total height of the mountain changes only slightly.

In this experiment, you will see the changes explained above by using the wooden blocks as mountain

materials and water as the underlying crust. Even though, the exact isostasy processes and forces will be

different than what is observed between wood and water (because we are discussing totally different

materials rock and soil versus woods and water) but the underlying principle is basically same. And of

course, it is totally impossible to perform the actual experiment involving a mountain, for which, we need

to be a giant monster bigger than the mountain itself!!!

Materials

Corn syrup, honey, clay putty (paper putty), disposable pipettes, two 5-mL pipets, an empty 20 Oz pop

plastic bottle, rubber cork with only one hole to fit the pipet, pipetting pump, two 100 mL beakers,

heating set up, 250-mL beaker, wooden blocks, 2000 mL beaker, ruler, thermometer.

Procedure

Part A: Viscosity Experiment

1. Bring two 125 mL clean and dry beakers and pour about 10 mL of corn syrup in one and 10 mL

honey in the other.

2. Bring a 5-mL pipet and insert the lower tip into a rubber cork so that the tip comes out of the cork

from the other side.

3. Cut the pop bottle from the middle to separate the top part (neck) and the bottom part (base).

4. Use the top part (having the neck) to fix the cork at the neck of the bottle so that the tip of the

pipet comes out 3 inches of the mouth of the bottle.

5. Fix the set-up vertically using a clamp and a stand. The bottle and the pipet should be vertically

standing after you fix with the clamp. To check if the bottle leaks, add some tap water into the

bottle. If it leaks, you should seal the leak or use another cork, or tighten the pipet, etc. whichever

is needed.

6. After this stage, you should become pro-active and need to start heating water for the second part

of this experiment. Bring a 250 mL beaker and fill about 2/3

rd

with the tap water. Set up a heating

arrangement using burner, ring clamp, wire gauge, and a stand. Set the beaker for heating.

7. Now returning back to the first part, bring a pipetting pump and fix it on the top of the pipet. With

the lower tip dipped in the corn syrup, pull the syrup up into the pipet using the pump. Stop when

you have reached the 5-mL mark. Remove the tip from the syrup and use a small piece of clay

putty to stopper the lower tip of the pipet. After properly sealing, remove the pump form the

pipet.

8. When you are ready with your timer, remove the putty and start the timer. One of you should also

count the number of drops falling from the pipet. Note down the time required to drop all 5 mL of

syrup from the pipet and also the number of drops in the data sheet.

9. Use the pipet pump to pump 5 mL syrup second time for the next part of the experiment. Put the

putty at the bottom of the pipet as before to seal it until you are ready.

10. Now your water should be around 80-90

o

C. For the second part of the experiment, place the hot

water into the bottle and let it heat the syrup in the pipet for 2 full minutes.

11. Now run the same drop counting and timing experiment after removing the putty from the pipet.

Note down the number of drops and total time taken to drop all 5 mL of syrup in the data sheet

12. Repeat the above two experiments (one without heat and one with heat) using honey this time.

Count the number of drops and total time required to drop all 5 mL of honey, both without

heating and with heating, in the data sheet.

35 | E a r t h S c i e n c e L a b M a n u a l

Part B: Height of Mountains and Isostasy

1. Bring a 2000 mL beaker and half fill with tap water.

2. Bring three wooden blocks and place two of the blocks, lying horizontally one on top of the other,

into the beaker.

3. From outside of the beaker, measure the submerged and floating depths of the combined blocks.

Note the depths on the data sheet.

4. Now add one more block on top of the two and measure the submerged and the floating depths of

the combined three blocks.

5. Now remove top two blocks and measure the submerged and floating depths of the single

remaining block.

36 | E a r t h S c i e n c e L a b M a n u a l

37 | E a r t h S c i e n c e L a b M a n u a l

Experiment 4: Magma Viscosity and Isostasy of Mountains

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is viscosity?

Q2. How is viscosity related to density?

Q3. How is viscosity related to temperature?

Q4. How is a mountain’s height related to its materials’ density?

Q5. What is isostasy?

Instructor’s approval____________________

38 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 4: Magma Viscosity and Isostasy of Mountains

Data Sheet

Part A: Viscosity Experiment

Write hypothesis 1: Write a suitable hypothesis regarding the two liquids and number of drops they will

make during the same amount of time.

_____________________________________________________________________________________

Write hypothesis 2: Write a suitable hypothesis regarding the relationship between temperature and

number of drops.

_____________________________________________________________________________________

Room temperature experiment

Syrup Honey

Amount of material taken in the pipet ____________ _____________

Number of drops formed ____________ _____________

Total time taken to empty the pipet ____________ _____________

Elevated temperature experiment

Syrup Honey

Amount of material taken in the pipet ____________ _____________

Number of drops formed ____________ _____________

Total time taken to empty the pipet ____________ _____________

39 | E a r t h S c i e n c e L a b M a n u a l

Answer the following questions

Q1. Was your hypothesis 1 proved? Explain.

Q2. Was your hypothesis 2 proved? Explain.

Q3. Why is it important to know about the viscosity of magma?

Q4. Which type of magma cause explosive eruptions? What is the cause behind it?

Q5. What are the factors that control viscosity of a material?

40 | E a r t h S c i e n c e L a b M a n u a l

Part B: Height of Mountains and Isostasy

Write hypothesis 1: State what you think will happen to the submerged portion of the block when one

block is added.

_____________________________________________________________________________________

Write hypothesis 2: State what you think will happen to the submerged portion of the block when one

block is removed.

_____________________________________________________________________________________

Height of the submerged portion with two blocks of wood _______________________

Height of the floating portion of the two blocks of wood _______________________

Height of the submerged portion with three blocks of wood _______________________

Height of the floating portion of the three blocks of wood _______________________

Height of the submerged portion of one block of wood _______________________

Height of the floating portion of one block of wood _______________________

Ratio of submerged portions (one block: two blocks: three blocks) _____ : _______ : _______

Simplified ratio of submerged portions (one block: two blocks: three blocks) _____ : _______ : _______

(divide all three numbers by the smallest number)

Ratio of floating portions (one block: two blocks: three blocks) _____ : _______ : _______

Simplified ratio of floating portions (one block: two blocks: three blocks) _____ : _______ : _______

(divide all three numbers by the smallest number)

Answer the following questions.

Q1. Was your hypothesis 1 proved or disproved? Explain.

41 | E a r t h S c i e n c e L a b M a n u a l

Q2. Was your hypothesis 2 proved or disproved? Explain.

Q3. Is there a correlation between submerged portion and the floating portion? If yes, what type of

correlation? If no, why should there be no correlation?

Q4. By looking at the height of a mountain, what hypothesis can be made regarding its root?

Q5. How will the results change if used syrup instead of water? Would the ratios be still the same?

42 | E a r t h S c i e n c e L a b M a n u a l

43 | E a r t h S c i e n c e L a b M a n u a l

Experiment 5: Minerals and Rocks: Part I

Objective: 1. To observe and record prominent features of provided minerals and igneous rocks

2. To identify the provided unknown minerals and igneous rocks

Introduction

Minerals are naturally found inorganic solids. However, some minerals are also synthesized in

laboratory. Minerals are composed of various types of atoms arranged in a specific regular pattern. The

regular nature of the atomic arrangement gives unique shape, size, and color - characteristic to that

particular mineral, wherever it is formed and wherever it is found.

Quartz Crystals Mystic Cavern in Arkansas (Photo: mysticcaverns.com)

Figure 5.1: Typical pyramidal quartz crystal and inside of a cave where minerals form from their

solutions by deposition on a surface.

Minerals are usually formed from their solutions in nature. Crystallization is a common process of

formation of a mineral. Evaporation of the solution and deposition of the mineral on the surface causes

crystals to be formed. Sometimes one mineral solution mixes with other solution and precipitate out the

insoluble mineral. The precipitated mineral is solidified under pressure. This is an example of chemical

method of formation of minerals.

Most minerals are crystalline in shape. It means that the minerals have certain regular repeating shape.

You will get to prepare crystals of borax in Experiment 7 yourself to see exactly how crystals are formed

from their solution. For now, we will study the given mineral crystals and observe their properties. Atoms

and molecules in crystals align themselves in a way to minimize the energy needed to form. Some

possible crystal shapes are needles, cubes, prism, pyramid, and sheets. Note the pyramidal shape of the

quartz crystal in the above figure 5.1.

Crystals tend to break along one or more planes. Such a propensity of crystals is called Cleavage. If the

bonding in the mineral is ionic (metal/non-metal bond) the mineral tends to break easily as compared to

the covalent bonding (non-metal/non-metal bond) minerals. Micas are very good examples of single-

cleavage-plane minerals where the thin sheets, one lying on top of the other, easily separate along that

parallel planes to make thin sheets. Note that cleavages are the regular break planes and not any breaking

lines. Quartz, for example, does not have any cleavage plane and thus the breaking pattern is irregular.

Some minerals have good metallic luster which means they can reflect light like metals and thus appear

like metals. Pyrite has a good metallic luster (Fig 7.12, textbook). Some minerals tarnish after being

exposed and are called to have sub-metallic luster, which is a dull, faded luster. Some non-metallic lusters

are described as vitreous (glassy), dull (earthly), pearly (like pearl), silky (like satin cloth or silk), greasy

(oily) etc.

44 | E a r t h S c i e n c e L a b M a n u a l

Igneous rocks are formed by cooling of magma in two ways. If the cooling occurs outside the volcano,

now the magma is called lava, the igneous rocks are called volcanic rocks. However, if the magma cools

inside the Earth’s crust, the igneous rocks are called Plutonic rocks.

Texture of the rocks depend on the grain size of the mineral crystals that form the rock. Volcanic

igneous rocks cool very fast and have smaller grain size. This is because there is no time for slow and

continuous growth of the crystals once the lava is exposed outside the surface of Earth. Plutonic igneous

rocks cool slowly and have big grain size, because slow cooling allows the growth of large crystals over

time. According to texture the igneous rocks are classified as follows:

1. Phaneritic – coarse-grained, roughly equal size, and evenly distributed throughout - plutonic

2. Aphanitic – fine grained, grains not visible without magnification –volcanic

3. Porphyritic – mixture of coarse and fine grained, results when cools in two different

environments, phenocrysts (large grains) embedded in matrix (small-grained mass) - both

4. Glassy – resembles processed glass, formed by very quick cooling even before atoms arrange to

crystals, shiny/slippery surface – volcanic.

5. Vesicular – with voids for gases that escaped, fine grained glassy fibers with vesicles – volcanic

6. Pyroclastic – fragmental, fragments of vent walls in ashes or blobs, light-weight – both

Color of igneous rocks is an important indication of their composition of silica. Whether they are

volcanic or plutonic, the light-colored ones have high silica content and dark-colored ones have low

silica content. Refer to Fig. 7.20 of Textbook (page 186) to identify the silica content based on color.

Materials Required

Provided samples of minerals and rocks, feldspar, mica, pyrite, halite, quartz, amphibole, textbook, test

tubes, hydrochloric acid, provided igneous rocks.

Procedure

Part A: Minerals

1. Record the features of given rocks such as name, color, crystal shape, cleavage, luster, and any

additional features that will be helpful to identify the rock when no name is given.

2. Also write any additional features not visible to our eyes such as its formation, source, location it

was found or is mostly found, if it is provided on the mineral information.

3. Bring a piece of mineral calcite provided and place it in a test tube. Add a drop or two of

hydrochloric acid. Record the observations.

4. Dispose of the waste as directed by your instructor.

Part B: Igneous Rocks

1. Record the features of given rocks such as name, color, grain size, texture, silica content, whether

plutonic or volcanic, and any other feature which will be helpful for identifying the unknown

rocks.

2. Also write any additional features not visible to our eyes such as its formation, source, location it

was found or is mostly found, if it is provided on the mineral information.

45 | E a r t h S c i e n c e L a b M a n u a l

Part C: Unknown Minerals and Rocks

1. Record the features of given minerals and rocks just as you did for the known minerals and rocks

in order to identify them

2. Write the name of the given unknown minerals and rocks that is mostly suitable for the studied

mineral or rock.

46 | E a r t h S c i e n c e L a b M a n u a l

47 | E a r t h S c i e n c e L a b M a n u a l

Experiment 5: Minerals and Rocks Part I

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What are minerals?

Q2. How are minerals formed?

Q3. What type of bond creates minerals with more cleavage? What is the reason behind it?

Q4. How do you distinguish volcanic and plutonic rocks based on their grain size?

Q5. How do you distinguish low or high silica content based on the rock color?

Instructor’s approval____________________

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49 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 5: Minerals and Rocks Part I

Data Sheet

Part A: Minerals

Name of the

provided

mineral

Color

Crystal shape

Cleavage

Luster

Other notable

features

50 | E a r t h S c i e n c e L a b M a n u a l

Observation of calcite mineral before adding hydrochloric acid __________________________________

Observation of calcite mineral after adding acid _____________________________________________

Identification of unknown Minerals

Sample

Number

Color

Crystal shape

Cleavage

Luster

Other notable

features

Name of the

Mineral

1

2

3

4

Answer the following questions:

Q1. Which mineral had the most distinct color that helped in its identification?

Q2. Which of the minerals provided had good metallic luster, a sub-metallic luster, or a non-metallic

luster?

Q3. Why do minerals have different crystals shapes?

51 | E a r t h S c i e n c e L a b M a n u a l

Q4. Which mineral had many cleavage? What is the reason behind it?

Part B: Igneous Rocks

Name of

the

Provided

Rock

Grain

Size

(small/

large)

Texture

(one of six

types)

Color

Silica Content

(High/intermediate

/low)

Volcanic

or plutonic

Additional info

52 | E a r t h S c i e n c e L a b M a n u a l

Identification of Unknown Igneous Rocks

Sample

number

Grain Size

Texture

Color

Silica Content

Volcanic or

plutonic

Name of the

Unknown

Rock

1

2

3

4

Answer the following questions:

Q1. Which rocks provided had a distinct texture regarding its grain size? Did you have any rock that was

hard to distinguish the texture? Mention the name.

Q2. How many of your rocks were volcanic and how many plutonic?

Q3. What is the most distinguishing feature of a volcanic rock?

Q4. Classify the given known rocks based on silica content.

High: ________________________________

Intermediate: ________________________________

Low: ______________________________________

53 | E a r t h S c i e n c e L a b M a n u a l

Experiment 6: Minerals and Rocks Part II

Objective: 1. To observe and record prominent features of provided sedimentary and metamorphic rocks

2. To identify the provided unknown sedimentary and metamorphic rocks

Introduction

Sedimentary Rocks are stratified rocks. This means that they form layers or beds, one over the other. If

you see a clearly distinguishable regularly arranged layers of rocks on an exposed rocky surface, most

possibly it is a sedimentary rock layer laid there millions of years ago.

Formation of sedimentary rocks occurs in a wide range of environments from dunes, to lagoons, beaches,

continental shelves, river deltas, ocean basin, reefs, alluvial plains, stream shores, and swamps.

Sedimentary rocks give valuable information about the past geological events from mountain formation to

climate to plate movements.

Three different types of sedimentary rocks are based on composition and formation: clastic, biochemical,

and chemical sedimentary rocks. Clastic sedimentary rocks are formed from previous rocks after

erosion. First the parent rock is eroded into pieces (generation), secondly they are transported to

different places (transportation), and finally they are deposited (lithification). The type of

sedimentary rock that will finally be made depends on the grain size (smallest to largest: clay, silt, sand,

gravel), velocity of the transporting medium (sorts out the grain size), and the location of lithification.

If the lithification process occurs due to the action of living organisms or if the living organisms are

trapped along with the minerals the resulting rocks are biochemical sedimentary rocks. E.g. calcite is

precipitated from seawater to make limestone, a biochemical sedimentary rock, from the actions of corals.

Chalks are made of dead organisms called coccolithophores. When plants are deposited in layers and are

trapped under high pressure and temperature, coal results. Oil and gas are results of similar sedimentation

of animals.

Precipitation and crystallization of minerals from their solutions results into chemical sedimentary

rocks. Most common example is the table salt. When a salty seawater collects in a hot area the

evaporation of water makes the solution concentrated and the salt is finally precipitated. The precipitated

salt is trapped under layers and becomes a future underground salt mine. More on this is discussed in

Chapter 7, when you study and practice crystallization process.

Metamorphic rocks are made from pre-existing rocks by pressure or heat. When heated or pressurized,

the mineral composition and the particle arrangement changes and consolidates the materials already

present changing the final form of rock – metamorphosed rocks! Remember, the rocks should only be

heated to a certain degree (usually ranging from 200

o

C to 1100

o

C) and pressurized accordingly to make

metamorphic rocks. At higher temperatures plutonic igneous rocks will be formed.

According to how the rocks are made, there are two types of metamorphic rocks: contact and regional

metamorphic rocks.

When rocks (sedimentary or igneous) are subjected to high temperature (baked! without melting), their

chemical composition remains the same but the crystal pattern is deformed or re-formed. Such denser

rocks formed due to the effect of heat (contact) are called contact metamorphic rocks. The heating

process usually occurs near the magma inside the earth. Marble made from limestone (sedimentary) and

Quartzite made from quartz (igneous) are examples of contact metamorphism.

54 | E a r t h S c i e n c e L a b M a n u a l

Regional metamorphism results due to high temperature as well as high pressure. Since pressure is

applied along with high heat, the crystals grow in a directional way and the resulting crystals are oriented

in the same direction. This usually results into foliation because the unidirectional orientation of minerals

produces streaks of regular lines within the rock. Some sedimentary and igneous rocks also show some

degree of foliation but we can easily distinguish metamorphic foliation by the high degree of alignment

including bending and folding due to tremendous pressure. Whether foliation occurs or not depends not

only on applied pressure and heat but also whether the parent rock has suitable mineral grains.

Materials Required

Provided samples of sedimentary and metamorphic rocks, textbook, unknown rock samples.

Procedure

Part A: Sedimentary Rocks

1. Record the features of given rocks such as color, texture, composition, and their possible

classification in the data table provided.

2. Write other non-visible features such as its formation, source, and location it was found or is

mostly found.

Part B: Unknown sedimentary Rocks

1. Record the features of given rocks as you would do for known sedimentary rocks such as color,

texture, composition etc.

2. Classify whether it is a clastic, chemical, or biochemical sedimentary rock.

3. Write the name of the given unknown rocks that is closest for the given properties.

Part C: Metamorphic Rocks

1. Record the features of given rocks such as color, composition, grain type, how it was formed, etc.

2. Write other features not visible to our eyes such as its source, location it was collected from etc.

Part D: Unknown Metamorphic Rocks

1. Record the features of given unknown rocks as you would do for the known metamorphic rocks.

2. Classify whether it is a contact or a regional type and then foliated or non-foliated. Also write

other features that are helpful.

3. Write the name of the given unknown metamorphic rock that is closest to the known

metamorphic rocks.

55 | E a r t h S c i e n c e L a b M a n u a l

Experiment 6: Minerals and Rocks Part II

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What are the sources of sedimentary rocks? Write four types of grain particles that make sedimentary

rocks.

Q2. What are three basic types of sedimentary rocks? Briefly describe each.

Q3. What are three steps by which clastic sedimentary rocks are made?

Q4. Why is temperature critical to form metamorphic rocks?

Q5. What is the main difference between contact metamorphic rocks and regional metamorphic rocks?

Instructor’s approval____________________

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57 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 6: Minerals and Rocks Part II

Data Sheet

Part A: Sedimentary Rocks

Name of

the

Provided

Rock

Color

Composition

(what could it

be made of)

Texture

(Soft/

hard/

grainy)

Location or

origin

Clastic,

biochemical,

or chemical

Additional info

58 | E a r t h S c i e n c e L a b M a n u a l

Part B: Unknown Sedimentary Rocks

Sample

number

Color

Composition

(what could it

be made of)

Texture

(Soft/

hard/

grainy)

Location or

origin

Clastic,

biochemical,

or chemical

Identification of

the unknown

rock

1

2

3

4

Answer the following questions

Q1. What role did you find of animals or plants to make some of the sedimentary rocks you studied?

Q2. What type of sedimentary rock are you studying if you see that the rock was actually formed by

precipitation of minerals from its solution?

Q3. From what you observed while studying the rocks, can sedimentary rocks be made from any other

pre-existing rocks? How do you support your answer?

59 | E a r t h S c i e n c e L a b M a n u a l

Part C: Metamorphic Rocks

Name of

Provided

Rock

Color

Composition

(what could it

be made of)

Foliated or

Non-

foliated

Contact or

Regional

Parent rock

(sedimentary

or igneous)

Additional info

Answer the following question

Q1. Which metamorphic rock provided was with most prominent foliation feature? Why do you think this

type of foliation might have occurred?

60 | E a r t h S c i e n c e L a b M a n u a l

Part D: Unknown Metamorphic Rocks

Sample

Number

Color

Composition

(what could it

be made of)

Foliated

or Non-

foliated

Contact or

Regional

Parent rock

(sedimentary

or igneous)

Name of the

unknown rock

1

2

3

4

Answer the following questions

Q2. What are the features you could observe in your unknown rocks that help you to distinguish whether

they are contact or regional metamorphic rocks?

Q3. From what you studied, can we clearly say whether the rock was metamorphosed from a sedimentary

or an igneous rock? Give a brief reason.

61 | E a r t h S c i e n c e L a b M a n u a l

Experiment 7: Mineral Crystallization

Objective: 1. To prepare the saturated solution of borax

2. To make crystals of borax using the saturated solution

Introduction

We studied and observed minerals in Experiment 5. We studied that minerals are naturally found

inorganic compounds made of one or more common elements of earth. Minerals are formed from their

solutions in nature in a slow process on or under the surface of earth. This chapter is more focused on

crystallization process which is one of the process of formation of minerals in nature or in laboratory or

industry.

Crystallization is the process of formation of solid crystals from their solution. When the solution

containing the minerals in high concentration slowly cools down the solid crystals start to form. The

beginning of formation of crystals from the solution is called seeding. Once seeding starts, it accelerates

the growth of many crystals around and starts formation of more crystals in every direction. The slower is

the process of formation of crystals, more uniform and regular crystals can be prepared.

We studied in Experiment 2 that a solution is made of solute and solvent and is a homogenous mixture.

We also prepared some solutions and measured their density. In order to make crystals though we cannot

use an ordinary solution, we have to use something called saturated solution. A saturated solution is a

solution of a very large amount of solute in the solution to the extent that the solution does not dissolve

some of the added solute. We also need to heat the solution so that the dissolving proves becomes faster.

When the hot saturated solution of a mineral is cooled slowly over time, crystals of that mineral are

formed.

Figure 11.1 Salt evaporation lake in Thar, India

In nature, the crystallization process occurs in various ways. In some cases, the solution on a flat surface

such as a lake dries out to give a residue of salt crystals. Playa Lakes in Thar Desert area in India are one

of the great sources of salt in the world. Here, a hyper saline brine is subjected to extreme sunlight (and

no rainfall) causing the solution to precipitate in the form of salt crystals (see picture above). Solution

62 | E a r t h S c i e n c e L a b M a n u a l

mining is the most common way of obtaining commercial table salt form salt beds. Wells are make over

the salt beds and fresh water is sent into the wells. The resulting brine is pumped out and evaporated in

production plants. The resulting salt is purified. The USA is the current top producer of world’s salt.

In this lab, we will learn to prepare a saturated solution of borax and then to prepare crystals from the

saturated solution. We will use borax as our salt to prepare crystals. Borax is a tetra borate salt of sodium

and is not same as the table salt which in turn is sodium chloride. Borax also has 10 molecules of water in

its fully crystalline form with the formula Na

2

B

4

O

7

·10H

2

O. Evaporation by sunlight is a natural process of

making table salt but we will use crystallization method for obtaining borax salt from its appropriately

prepared solution.

For more information on minerals and crystals see page 180-184 in Textbook.

Materials

Borax, heating set-up, stirring rod, 250-mL beaker, 100-mL beaker, petri dish or watch glass, beaker

tongs or heat gloves, weigh boat, scoop, digital balance, pipe cleaners.

Procedure

Use following procedure in the order given.

1. Assemble the heating set-up.

2. Bring a 250-mL beaker and place exactly 100 mL of DI water.

3. Set the water for heating.

4. Bring a clean and dry 100-mL beaker and record its mass.

5. Bring a weigh boat and weigh out 10 grams of borax using a scoop form the stock container.

6. As the water starts boiling, add borax using a scoop, a little at a time to allow the proper

dissolution. Keep stirring every time you add borax into the solution until it completely dissolves.

7. If you are out of the weighed borax and still keeps dissolving, get more but keep track of the

borax added.

8. Once you see the added borax does not dissolve any more, you should stop adding more borax

and stop heating.

9. To find the total amount of borax added, subtract the amount left behind from the total you

weighed. Record the total mass of borax dissolved. You will need this amount to find the

10. Using the beaker tongs or heating gloves, transfer the solution only, not the undissolved borax,

slowly to a 100-mL beaker.

11. This is your saturated solution of borax.

12. This is the time to add some color to the solution if you want to prepare colorful crystals.

13. Bring a clean and dry petri dish and record its mass.

14. Pour a little of the solution into a petri-dish using the glass stirring rod to cover the bottom and set

it aside for cooling, undisturbed.

15. Bring a pipe cleaner and make a shape of your choice out of it but it should fit into the beaker

while hanging. Record the mass of the pipe cleaner. Hang the pipe cleaner from the top of the

beaker using a glass rod. Set this set-up aside for cooling.

16. Observe the petri-dish for any formation of crystals and record your observation in the data sheet.

17. Write your group’s name on the petri-dish and the beaker and let them sit for overnight. If you

have class next day, do not forget to check your crystallization process. If you wait until next

class time, you will probably miss the process of formation of crystals in the intermediate stage

and you will only see the fully crystallized product.

63 | E a r t h S c i e n c e L a b M a n u a l

18. After full crystallization process is complete, decant any water left behind in the petri-dish and

the beaker and set them for drying. When completely dry record the mass of the petri-dish with

the crystals as well as the beaker plus the crystals.

19. Form the total mass of everything, subtract the mass of the beaker, the petri dish and the pipe

cleaner to find how much total crystals you made.

64 | E a r t h S c i e n c e L a b M a n u a l

65 | E a r t h S c i e n c e L a b M a n u a l

Experiment 7: Mineral Crystallization

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is crystallization? What are conditions needed for crystallization process?

Q2. What substances undergo crystallization? Give some examples.

Q3. Define a saturated solution. What does heat do to a saturated solution?

Q4. What happens when a saturated solution cools under normal temperature?

Q5. Where in nature does crystallization occur? Give examples.

Instructor’s approval____________________

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67 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 7: Mineral Crystallization

Data Sheet

Write hypothesis: State how do you expect the process of crystallization will occur. Will you get the

amount you started with at the end of the process?

_____________________________________________________________________________________

Mass of clean dry 100-mL beaker ______________

Amount of water used to make solution (mL) ___________________

Total amount of borax used in making saturated solution ____________________________

Appearance of borax before dissolution ______________________________________

Mass of the petri-dish _______________________

Mass of the pipe cleaner used for crystallization ___________________________

Appearance of the petri-dish as it is cooling __________________________

Description of the observation of the process of crystallization (next day)

Description of the final product after completing crystallization

68 | E a r t h S c i e n c e L a b M a n u a l

Total mass of crystals recovered from the whole experiment ______________________

(Don’t forget to subtract the beaker, petri-dish, and the pipe cleaner masses)

Change in mass than what you started with _______________________

Answer the following questions

Q1. Were your hypotheses proved? To which extent?

Q2. What was the purpose of dissolving the borax a little at a time?

Q3. Why should the process be allowed so much time?

Q4. What difference would you expect to find if the process was expedited by placing the solution in a

fridge?

Q5. What are the possible sources of error in this experiment?

Q6. Which natural processes are very close to the crystallization in the petri-dish and which process is

close to one in the beaker?

69 | E a r t h S c i e n c e L a b M a n u a l

Experiment 8: Albedo Effect

Objective: 1. To record the temperatures of various landmasses.

2. To identify and discuss the role of particular landmass in maintaining Earth’s temperature

Introduction

The ultimate source of light and heat for earth is sun. The electromagnetic radiation from sun reaches the

Earth through the atmosphere and in the process, much of the harmful radiations are captured and blocked

by the atmosphere. The remaining solar radiation that reaches the Earth surface is used to harvest energy

for plants for photosynthesis and is passed onto the other life forms. However, several processes happen

in the atmosphere and on the surface of Earth after receiving solar energy. Some of the processes are

described below.

Scattering of electromagnetic radiation causes the energy to scatter or spread out into the atmosphere and

beyond. When the electromagnetic radiation strikes small particles such as dust and gas molecules in the

atmosphere, it changes the direction. The sky looks blue due to this property of the radiation. Blue light is

scattered more easily than other colors and reaches to our eyes, making the sky appear blue. Same

phenomenon happens when light strikes the water molecule. They scatter the blue light which comes to

our eye.

Some of the electromagnetic radiation gets reflected back to the space from the particle or object which it

strikes. This is the property we will mainly focus on in this experiment. Light can be reflected by various

objects such as atmosphere itself (gases, dust, smoke etc.), clouds, trees, snow and ice, rocks, water, man-

made structures etc. The extent of reflection of radiation depends what the object is made of, what color it

is, and how smooth the surface is. The measure of reflecting capacity of objects is called albedo. Albedo

is usually measured in percentage unit. Above 90% albedo naturally means very high reflectivity and

below 10% albedo means very low reflectivity.

Some of the radiation gets absorbed by the molecules in which case the molecules do not give back the

energy but keep in themselves and change into other forms such as heat. If the object is keeping the

radiation it gets, obviously it is reflecting less, which means it has low albedo effect. Carbon dioxide gas

is very good absorber of heat because it can trap the solar radiation and gets itself heated. That is why, the

area that produces carbon dioxide a lot is relatively warm. Besides carbon dioxide, black soot from

burning object also have a very good absorbing capacity.

Greenhouse effect is a scenario where, like in a greenhouse, the incoming radiation is trapped in the

molecules themselves and will not be reflected back into the space. This increases the average

temperature of the atmosphere and the underlying places because after absorbing the radiation they

radiate hot infrared radiation. Therefore, places with less albedo have more greenhouse effect and have

higher temperature than places with high albedo.

For more information on albedo effect see Textbook page 388-389 and related content.

Materials

Temperature sensor probe, computer interface.

70 | E a r t h S c i e n c e L a b M a n u a l

Procedure

1. Bring a Vernier temperature probe and connect to the correct port of the Lab Quest computer

interface.

2. You should be able to see the temperature of the probe in the interface already. If it does not give

you the temperature, it is not well connected or is broken.

3. Check the probe by gripping between your fingers and see the temperature increase.

4. Bring the data page with you and get ready to collect data at different locations outside as

mentioned in the data sheet.

5. Record the temperatures in the shade and light of the same type at two different locations and find

the average.

6. Repeat the same for other locations and answer the given questions.

71 | E a r t h S c i e n c e L a b M a n u a l

Experiment 8: Albedo Effect

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What represents Earth’s albedo?

Q2. What are three possibilities that happen to incoming solar radiation?

Q3. What types of objects absorb more sunlight and what types of objects reflect more?

Q4. What is greenhouse effect? What gas is mainly responsible for it?

Q5. Which area will usually have high temperature - right above the surface or high above the surface?

Why?

Instructor’s Approval____________________

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73 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 8: Albedo Effect

Data Sheet

Write hypothesis: State which landmass will have the highest temperature and which will have the

lowest temperatures.

_____________________________________________________________________________________

Record the temperature of the following places around campus.

Location 1 Location 2 Average

Parking lot asphalt (shaded area) ____________ ____________ _____________

Parking lot asphalt (lighted area) ____________ ____________ _____________

Sidewalk cement (shaded area) ____________ ____________ _____________

Sidewalk cement (lighted area) ____________ ____________ _____________

Grass (shaded area) ____________ ____________ _____________

Grass (lighted area) ____________ ____________ _____________

Edge of a pond (shaded area) ____________ ____________ _____________

Edge of a pond (lighted area) ____________ ____________ _____________

Answer the following questions.

Q1. Was your hypothesis proved? Explain your observation.

74 | E a r t h S c i e n c e L a b M a n u a l

Q2. Between the lighted and shaded area of the same location, which one had the higher temperature?

What could be the possible cause of this?

Q3. Which location had the greatest albedo? What may be the possible cause of that?

Q4. Which location can cause the greatest greenhouse effect and keep the atmosphere warm?

Q5. Use the above data to interpret why we feel cool by a lakeside in a summer day.

Q6. Which roof color (dark or light) do you suggest for a house in an area that has yearly average

temperature of 40

o

F? Explain. What if the house was in Miami, Florida?

75 | E a r t h S c i e n c e L a b M a n u a l

Experiment 9: Psychrometer Experiment

Objective: 1. To use a psychrometer to measure temperatures of dry and moist air

2. To determine the relative humidity and the dew point temperature of surrounding air using

these temperatures and given standard tables

Introduction

Water vapor is one of the components of the atmosphere along with nitrogen, oxygen, carbon dioxide,

ozone, and other gases. Even though water vapor occupies only a little fraction of total volume of

atmospheric gases (0.1 to 4%), it actually has lot more importance regarding its role in maintaining the

atmospheric condition of a particular location. In simple terms the water vapor content of air is called its

humidity.

Water is continuously evaporating from the Earth’s surface into atmosphere. The pressure of water vapor

in the atmosphere is called vapor pressure. The vapor pressure increases when water keeps evaporating

from the surface. As soon as the vapor pressure reaches to a limit, the atmosphere can no longer hold any

more water vapor. This situation is called saturation. You have worked with a saturated solution in

Experiment 7 in which you prepared crystals from a saturated solution: the solution can no longer any

more solid. This is a similar analogy, but with water vapor this time. After saturation level is reached, the

water vapor accumulated in the atmosphere starts to gather more water molecules together (clumping) and

becomes heavy. This causes precipitation in the form of rain, hail, ice, or snowfall depending on

temperature.

Rather than absolute humidity, we frequently hear relative humidity in weather statements. Relative

humidity is a term used to express how close the air is from saturation level. Relative humidity is

mathematically calculated by finding the percentage of actual water vapor content in per kg of air

compared with the amount of water vapor needed per kg of air to make the air saturated.

Relative humidity = Actual amount of water vapor per kg x 100

Amount of water vapor needed per kg air to make it saturated

The amount of water vapor needed per kg of air to make the air saturated with water vapor is also called

mixing ratio. The value of relative humidity is expressed in percentage. The precipitation condition

mentioned above is reached when the relative humidity is 100%.

In this lab we will measure the relative humidity by using an instrument called psychrometer. This is the

method of finding the relative humidity using temperature difference. A typical psychrometer has two

thermometers: dry-bulb thermometer and wet-bulb thermometer. The bulb of a dry-bulb thermometer

directly measures the temperature of the surrounding air. The bulb of a wet-bulb thermometer is wrapped

around by a piece of a cloth which is made wet before actually measuring the temperature. When the

psychrometer is spun by using the handle, the wet bulb starts accelerated evaporation of water and cools

down the bulb fast. The difference between the dry- and wet-bulb temperatures is called the depression

of the wet bulb (how much below the wet-bulb temperature is from the dry-bulb temperature) and is used

to determine relative humidity using Table 1.

Dew-point temperature is the temperature at which the air can no longer hold the water vapor mixed in it

and starts forming liquid water. High dew-point temperature in a particular day means that there is high

amount of water vapor in the air and the formation of dew starts at that high temperature that day. Lower

dew-point temperature means that the dew formation starts only after reaching that lower temperature

76 | E a r t h S c i e n c e L a b M a n u a l

because the air has less water vapor in it. Dew-point temperature is also determined using the

psychrometer and a standard conversion table. You will use Table 2 below to determine the dew-point.

Table 1: Relative Humidity Conversion Table

Dry Bulb

Tempera-

ture (

o

C)

Difference between Dry bulb and Wet bulb temperatures (

o

C)

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

-20

100

28

-18

100

40

-16

100

48

-14

100

55

11

-12

100

61

23

-10

100

66

33

-8

100

71

41

13

-6

100

73

48

20

-4

100

77

54

32

11

-2

100

79

58

37

20

1

0

100

81

63

45

28

11

2

100

83

67

51

36

20

6

4

100

85

70

56

42

27

14

6

100

86

72

59

46

35

22

10

8

100

87

74

62

51

39

28

17

6

10

100

88

76

65

54

43

33

24

13

4

12

100

88

78

67

57

48

38

28

19

10

2

14

100

89

79

69

60

50

41

33

25

16

8

1

16

100

90

80

71

62

54

45

37

29

21

14

7

1

18

100

91

81

72

64

56

48

40

33

26

19

12

6

20

100

91

82

74

66

58

51

44

36

30

23

17

11

5

22

100

92

83

75

68

60

53

46

40

33

27

21

15

10

4

24

100

92

84

76

69

62

55

49

42

36

30

25

20

14

9

4

26

100

92

85

77

70

64

57

51

45

39

34

28

23

18

13

9

28

100

93

86

78

71

65

59

53

47

42

36

31

26

21

17

12

30

100

93

86

79

72

66

61

55

49

44

39

34

29

25

20

16

Materials

A psychrometer, beaker, the relative humidity chart, dew point chart, calculator

Procedure

Follow the given procedure.

1. Bring a psychrometer provided. Check if the cloth wrapped around the wet bulb thermometer is

loose. If it is loose, the chances are it will get removed while spinning the psychrometer. Also

make sure that the thermometer liquid (if red, it should be ethanol) is uniform all throughout the

capillary. If there are gaps, it will not give the right temperature.

2. Read the constant dry air temperature using the dry bulb thermometer and record it in the data

sheet

(… Continued after Table 2)

77 | E a r t h S c i e n c e L a b M a n u a l

Table 2: Dew-Point Conversion Table

Dry Bulb

Tempera-

ture (

o

C)

Difference between Dry bulb and Wet bulb temperatures (

o

C)

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

-20

-33

-18

-28

-16

-24

-14

-21

-36

-12

-18

-28

-10

-14

-22

-8

-12

-18

-29

-6

-10

-14

-22

-4

-7

-12

-17

-29

-2

-5

-8

-13

-20

0

-3

-6

-9

-15

-24

2

-1

-3

-6

-11

-17

4

1

-1

-4

-7

-11

-19

6

4

1

-1

-4

-7

-13

-21

8

6

3

1

-2

-5

-9

-14

10

8

6

4

1

-2

-5

-9

-14

-28

12

10

8

6

4

1

-2

-5

-9

-16

14

12

11

9

6

4

1

-2

-5

-10

-17

16

14

13

11

9

7

4

1

-1

-6

-10

-17

18

16

15

13

11

9

7

4

2

-2

-5

-10

-19

20

19

17

15

14

12

10

7

4

2

-2

-5

-10

-19

22

21

19

17

16

14

12

10

8

5

3

-1

-5

-10

-19

24

23

21

20

18

16

14

12

10

8

6

2

-1

-5

-10

-18

26

25

23

22

20

18

17

15

13

11

9

6

3

0

-4

-9

28

27

25

24

22

21

19

17

16

14

11

9

7

4

1

-3

30

29

27

26

24

23

21

19

18

16

14

12

10

8

5

1

Procedure (Continued…)

3. Bring a beaker (size does not matter) and half fill it with tap water.

4. Now dip the wet bulb of the psychrometer fully into water.

5. Lift the psychrometer up, make sure you have enough space for spinning, hold the handle firmly,

and spin the psychrometer for 1 full minute. Measure the lowest temperature reached and record

in the data sheet. You should do two more trials to make sure that you measured the lowest

temperature. If one of the trials does not seem right, repeat it.

6. Repeat above process of recording the dry bulb and wet bulb temperatures for two more

locations: one outside in the parking lot, and another near the pond. Take your beakers with water

with you while performing the experiment outside.

7. After recording all three location data, use the tables and appropriate formula to find the relative

humidity of air at these three locations.

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79 | E a r t h S c i e n c e L a b M a n u a l

Experiment 9: Psychrometer Experiment

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is humidity?

Q2. Which air is called a saturated air?

Q3. What is the difference between humidity and relative humidity?

Q4. How do you calculate depression of the wet-bulb temperature? If the dry bulb temperature is 32

o

C

and wet bulb temperature is 28.5

o

C, what is the depression of the wet-bulb?

Q5. What are the conditions of a rainfall to occur?

Instructor’s approval____________________

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81 | E a r t h S c i e n c e L a b M a n u a l

Date

Name

Lab Partner

Experiment 9: Psychrometer Experiment

Write hypothesis: Which area among the three mentioned in the data sheet probably has highest relative

humidity and which one has the lowest? Why do you think so?

_____________________________________________________________________________________

Data Sheet

Relative Humidity of a Laboratory Room

Trial 1 Trial 2 Trial 3

Dry-bulb thermometer temperature __________ __________ __________

Wet-bulb thermometer temperature __________ __________ __________

Difference between dry- and wet-bulb temperatures __________ __________ __________

Relative humidity using the table provided __________ __________ __________

Dew-point temperature using the table provided __________ __________ __________

Average relative humidity of the laboratory ____________

Dew-point temperature of the laboratory ____________

Relative Humidity of a Parking Lot

Trial 1 Trial 2 Trial 3

Dry-bulb thermometer temperature __________ __________ __________

Wet-bulb thermometer temperature __________ __________ __________

Difference between dry- and wet-bulb temperatures __________ __________ __________

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Relative humidity using the table provided __________ __________ __________

Dew-point temperature using the table provided __________ __________ __________

Average relative humidity of the parking lot ____________

Dew-point temperature of the parking lot ____________

Relative Humidity near a pond

Trial 1 Trial 2 Trial 3

Dry-bulb thermometer temperature __________ __________ __________

Wet-bulb thermometer temperature __________ __________ __________

Difference between dry- and wet-bulb temperatures __________ __________ __________

Relative humidity using the table provided __________ __________ __________

Dew-point temperature using the table provided __________ __________ __________

Average relative humidity near the pond ____________

Dew-point temperature near the pond ____________

Answer the following questions.

Q1. Was your hypothesis proved? Explain.

Q2. What may be the reason behind the average relative humidity values being not vastly different among

the places you experimented?

83 | E a r t h S c i e n c e L a b M a n u a l

Q3. Using the tables, determine the relative humidity and the dew point temperature of a place where the

dry bulb temperature is 40

o

C and the wet bulb temperature is 35

o

C.

Relative humidity value ______________

Dew-point temperature value _________________

Q4. Write your observation about the dew-point temperature values of three different places you tested.

Q5. What does it mean if the dew-point temperature of your location during mid-March is 32

o

F?

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Experiment 10: Coriolis Effect

Objective: 1. To construct a Coriolis Effect experiment set-up

2. To observe the Coriolis Effect in the Northern and the Southern Hemispheres.

Introduction

Coriolis Effect is a deflective effect on moving objects such as wind and water on or above the surface of

Earth because of Earth’s rotation. It states that all free-moving objects are deflected to the right of their

path of motion in the Northern Hemisphere and to the left in the Southern Hemisphere. For Example, (See

Figure 10.1) if the wind is blowing in the direction from Oklahoma City to Tulsa, as the original route,

due to Coriolis Effect the wind will be deflected to somewhere near Muskogee, as shown in the map. This

deflection is to the right of the original direction since this location is in the Northern Hemisphere.

Figure 10.1: Coriolis Effect in Northern Hemisphere

Similar deflection occurs in the Southern Hemisphere, but to the left of the original direction.

Laws of physics and vector calculations can be used to compute exactly where the objects such as wind

will end up if we know the initial velocity of wind. Discussion, understanding of the laws and calculation

of these values is beyond the limit of this laboratory manual. But it will be a valuable information to

know the actual cause of Coriolis Effect, which is discussed below.

The Earth is rotating about its rotational axis at an approximate speed of 25,000 miles per day at the

equator region. Note that this speed is at the equator only and if you move towards the poles, the speed

goes on decreasing. At the pole the object is only rotating about its own axis because the rotation axis of

Earth passes right through the North and the South poles. 25,000 miles per day of speed means that an

object (or a man) right on the equator is moving at about the speed of 1042 mph! That is indeed a very

high speed and is hard to imagine. Why do we not feel it then? That is because along with us, every other

objects are also moving at the same speed, and relatively speaking we are not moving at all. This is like a

seat and a passenger in a moving car. Relative to the seat the passenger is not moving. This becomes more

imaginable if you take an example of a passenger in a flying plane in the very middle row with no

windows to compare the motion with outside objects.

Original route

Route after

Coriolis Effect

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Let’s go back to the point, what is the cause of Coriolis Effect? Since objects at different latitude are

moving at a different speed along with Earth’s rotation, the moving objects such as wind will be relatively

moving faster than the ground below, it reaches a further location earlier. Take the example of wind from

Oklahoma City to Tulsa. Since OKC is rotating faster than Tulsa (since it is close to equator than Tulsa),

the wind from OKC is travelling even faster than Tulsa (since wind itself has a speed), wind reaches to a

location further east of Tulsa, which is in right direction. If you were to throw a projectile from Tulsa to

OKC, it will reach to a place right of OKC, because by the time the projectile has reached OKC would

have moved further east due to its higher speed.

Now you can easily analyze that if the speed of rotation of the planet were to increase, we will observe

more Coriolis Effect, and if the speed of rotation decreases the Coriolis Effect decreases. If the size of

the planet were to increase keeping the rotation time same, the Coriolis Effect also increases. This is

because the object on the equator of a bigger planet has to cover much more distance in the same time

than the object on the equator of the smaller planet.

Ocean water currents are caused also due to Coriolis Effect and the atmospheric currents. The upper 100

meters of ocean water follows the overlying wind current and its force to determine where to go. The

ocean water follows the direction of the wind until blocked by a landmass. As a result, the ocean water

currents, known as gyres, rotate clockwise if it is the Northern Hemisphere and anticlockwise if it is the

Southern Hemisphere. It is these gyres which circulate the waters of the oceans from tropical regions to

the poles and from poles back to the tropical regions. This helps in maintaining the temperature and saline

content of the ocean waters.

In this lab you will learn to draw imaginary gyres of material (air or water) movement due to Coriolis

Effect and see the effect of rotation speed and direction in formation of these gyres. You will use simple

geometric techniques to construct your own Coriolis Effect diagrams.

For more information on Coriolis Effect see page 356 of textbook.

Materials

Blank white heavy paper, Cardboard paper, thumb tack, ruler, pencil, tape, scissors,

Procedure

1. Bring a flat head thumb tack and a piece of cardboard paper provided.

2. At the center of the cardboard paper, mark a circle and place the thumb tack on the circle with the

pin turning upward.

3. Use a piece or two of tape to hold the thumb tack in position.

4. You can tape the cardboard on the table top of your station so that it does not move when you

work with it.

5. Now bring a heavy paper and label it ‘no rotation’. Insert the pin of the thumb tack through the

center of the paper so that it sticks out of paper when the paper lies flat on the table.

6. Bring a ruler and place the straight edge of it, the side does not matter, against the pin of the

thumb tack.

7. With a pencil draw a straight line on the paper through the edge of the ruler passing through the

pin and along the whole length of the ruler. This line represents no rotation of the Earth. That is to

say “if the Earth were not rotating,” which means there is no Coriolis Effect. Draw an arrow

pointing from the starting point to the ending point of the line drawn.

8. To represent the Coriolis Effect on the Northern Hemisphere, bring another paper and label it

‘Northern Hemisphere’. Let your partner slowly rotate the paper counterclockwise while fixing

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the ruler in its position and draw the line through the straight edge of the ruler, just like you did in

the ‘no rotation’ case. Draw an arrow in the direction of the movement of the pencil. Label this

line (curve) ‘slow rotation’.

9. Now starting from the same point of the ruler, repeat step 8 two more times with the speed of

rotation increasing slightly each time. Label the second rotation curve ‘fast rotation’ and the third

rotation curve ‘very fast rotation’.

10. To represent the Coriolis Effect on the Southern Hemisphere, bring a new paper and label it

‘Southern Hemisphere’. Follow all procedures you did in step 9, except the rotation direction is

opposite, i.e. clockwise. Label all three arrows accordingly.

11. Compare and contrast the curves and lines in each case in the data sheet. Save these papers for

next week to attach with your lab report next week at the end of it, with the name of your lab

partner.

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Experiment 10: Coriolis Effect

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What is a Coriolis Effect?

Q2. Why does Coriolis Effect occur in opposite direction in the Northern and the Southern Hemispheres?

Q3. Why do we not feel that the Earth is rotating at a very high speed?

Q4. What effect is seen in Coriolis Effect if the rotation of Earth were to occur faster or slower?

Q5. What causes the ocean water circulation gyres? What would happen to the speed of gyres if the Earth

were to rotate faster?

Instructor’s approval____________________

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Date

Name

Lab Partner

Experiment 10: Coriolis Effect

Write hypothesis: How are your results probably going to come out in all three cases mentioned below

in the data sheet?

_____________________________________________________________________________________

Data Sheet

No rotation

Shape of the arrow drawn _____________

Statement about the shape of the arrow drawn

_____________________________________________________________________________________

Northern Hemisphere

Shape of the curve drawn ‘slow rotation’ _____________

Shape of the curve drawn ‘fast rotation’ _____________

Shape of the curve drawn ‘very fast rotation’ _____________

Statement about the shapes of the curves drawn

_____________________________________________________________________________________

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Southern Hemisphere

Shape of the curve drawn ‘slow rotation’ _____________

Shape of the curve drawn ‘fast rotation’ _____________

Shape of the curve drawn ‘very fast rotation’ _____________

Statement about the shapes of the curves drawn

_____________________________________________________________________________________

Answer the following questions.

Q1. Was your hypothesis proved about the rotation patterns and the curves built? Explain.

Q2. What are the possible ways of errors in this experiment?

Q3. What was the effect of faster rotation compared to slower rotation in Coriolis Effect? Will Coriolis

Effect in Earth change over time?

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Q4. From what you have learned in this experiment, analyze the Coriolis Effect in the following two

planets:

a) Venus: about the same size as Earth, rotation period 244 days of Earth

b) Jupiter: much larger than Earth, rotation period 10 hours of Earth

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Experiment 11: Insolation Pattern

Objective: 1. To measure the solar angle of your location over the spring season

2. To analyze the angle and solar energy distribution pattern based on the data collected

Introduction

As you are aware that sun plays vital role in not only providing the energy needed for life on Earth but

also for change of seasons, regulation of its temperature, and different atmospheric phenomena. Earth’s

orbit around the sun is not perfectly circular but is slightly elliptical. Due to this reason, the Earth comes a

little closer to the sun during the month of January and goes slightly farther in the month of July. If so,

why is the summer hot and winter cold in the Northern Hemisphere? This is where you should be careful

not to get confused. It is not the distance of the sun that is causing the seasons, it is the angle the solar

rays are falling on the surface of Earth. The amount of solar radiation distributed on Earth is called

Insolation. Insolation is high when the sun’s rays are falling vertically (at larger angle) on the Earth

surface and is low when the rays are falling at a slanting, smaller angle.

January is a winter month in the Northern Hemisphere. What does this mean? It means that the solar rays

reach the Earth’s surface at a smaller angle and have longer path through the atmosphere. This causes loss

of heat to the atmosphere. It also means that the solar rays cover the curved surface of the Earth causing

the energy to distribute over large area. So the temperature in the Northern Hemisphere during these

months are low.

What happens in the Equator region during these months then? Equator is directly facing the sun and

therefore gets direct solar rays during this time of year. Total amount of energy per unit area is high here

so the average temperature in this tropical region is high. Equator receives 2.5 times higher amount of

solar radiation than polar region.

Since the Earth’s rotation axis is tilted at 23.5

o

from the revolution plane (the vertical axis), days and

nights in the hemispheres are not equal and keep changing throughout the year. Only on the Equinoxes

(Spring Equinox, March 20 and Fall Equinox, September 22) the days and the nights are equal because

the sun is directly overhead at the Equator. Sun is overhead at the Tropic of Cancer (23.5

o

north of

Equator) on June 21(Summer Solstice) and at the Tropic of Capricorn (23.5

o

south of Equator) on

December 21 (Winter Solstice). These statistical values and data help us to analyze the differences in the

insolation pattern at different places on Earth.

In this experiment you will use a simple trigonometry formula to find the sun’s angle using a meter-stick

and measuring tape. A vertically standing meter-stick casts a shadow on the ground in a sunny day. The

stick represents the height of a right triangle and the shadow represents the base of the triangle as shown

in Figure 11.1. The sun’s angle is then represented by the angle on the base as shown in the diagram.

This angle decreases when the shadow gets longer, which is shown in the second triangle. The angle can

be calculated by using following formula:

Tan θ = height / base where, θ is the sun’s angle.

Or, θ = Tan

-1

(height / base)

To find θ, first divide the height by the base. Now, in your calculator use Tan

-1

(answer). This gives the

required angle.

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height same height

sun’s angle, θ smaller sun’s angle, θ

shadow = base longer shadow = longer base

Figure 11.1: Representation of a right triangle and dependence of its angle.

For more information on insolation see page 43 of Textbook.

Materials

A meter-stick, a piece of chalk, measuring tape, scientific calculator.

Procedure

This is a whole semester project. You will need to record the data each week on a sunny day afternoon.

Follow the procedure below to record data each day starting your first lab period of semester.

1. Bring a meter-stick, a piece of chalk, and a measuring tape with you outside of the building. Find

a spot on the side walk, parking lot, or any place that is suitable to record the data without

disturbance for the whole semester. Also identify a distinct mark on the spot so that you do not

forget it because you will need to do this experiment on the same spot every time.

2. After you and your partner agree upon the spot, one of you should position the meter-stick

vertically upright so that the shadow falls on a plane surface. If something comes on the way of

shadow, either remove the object or you should change the spot.

3. One of you should mark the tip of the shadow with a piece of chalk while the other holds the

meter stick upright. Now measure the distance between the bottom of the meter stick and the

chalk mark. This gives the base of the triangle. Measure the actual height of the meter-stick,

which is the height of the triangle. Now follow the method described above to find the sun’s

angle.

4. Repeat the steps 1-3 next week on the same day and time. Do this process until the semester ends

or your instructor tells that you have enough data.

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Experiment 11: Insolation Pattern

Pre-laboratory Questions

Complete this page before coming to the lab. Read the information given to answer the following

questions.

Q1. What do you mean by insolation?

Q2. On which factors does the insolation depend?

Q3. Why is January a cold month in the Northern Hemisphere?

Q4. Which places are above average temperatures throughout the year? What is the cause behind this

constantly high temperatures?

Q3. If the height of a right triangle is 4.5 cm and the base (of the shadow) is 8.0 cm, what is the sun’s

angle?

Instructor’s Approval __________________

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Date

Name

Lab Partner

Experiment 11: Insolation Pattern

Write hypothesis: Write how the insolation pattern would change over the semester.

_____________________________________________________________________________________

Data Sheet

Fill out the following table for height and shadow length to find the sun’s angle.

Week

Date

Height (h)

Shadow length

(b)

b/h

θ (sun’s angle)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Show calculation of the sun’s angle for one of the data points in the space below.

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Plot the sun’s angle against the date (time of the year) in the graph below. The time of the year is

represented along the x-axis and the angle is represented along the y-axis. Use the format Jan 18, Feb 17

etc. for the date along the x-axis.

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Answer the following questions.

Q1. Was your hypothesis proved or disproved? Explain.

Q2. What were the limitations and obstacles during your experiment? How could they be possibly

overcome?

Q3. You did this experiment on the location (your college campus) which is about 34.6

o

north of Equator,

i.e. Northern Hemisphere. If you were to perform this experiment on the 34.6

o

south of Equator I.e.

Southern Hemisphere on the same days and time, how will the results be affected? Explain.

Q4. You did this experiment after December 21

st

, the shortest day, Winter Solstice. If you were to do the

same experiment after the Summer Solstice, June 21

st

, how will your results be affected? Explain.

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References

1. Lutgens, F. K. and Tarbuck, E.J., Foundations of Earth Science, Seventh Edition, 2014, Pearson

Education Inc.

2. Ludman, A. and Marshak, S., Laboratory Manual for Introductory Geology, Second Edition,

2012, Norton Company, Inc.

3. McConnell, D. and Steer, D., The Good Earth Introduction to Earth Science, Third Edition, 2015,

McGraw Hill Education

4. Lutgens, F. K., Tarbuck, E.J., and Pinzke K. G., Applications and Investigations in Earth Science,

Eighth Edition, 2015, Pearson Education Inc.