Manchester Community College Wk 2 Convection Currents Lab Report

LAB TOPIC: Using Time Travel Curves to Locate Epicenters(B)
Introduction
Seismograms are records of earthquake activity. They record both the severity and
duration of the shocks produced by earthquakes. There are seismograph stations all over
the world which are constantly recording information about earthquakes as they occur.
Seismologists use this information to create a time-travel curve that tells them how far
away from the epicenter their station is. They determine the distance by the arrival time
of the P, S, and surface waves and share this with other stations. With the information
from at least three different stations seismologist can determine the location of the
epicenter. (See page 129) In this exercise you will recreate how seismologists locate
epicenters using seismograms.
Materials
3 Earthquake maps
Compass and pencil
Procedure
You will need to download the pictures to a word file and print them out. Do your work
on them and then scan them into a word file or take pictures and submit with your report.
1. On map 1 there are three different seismograph stations named A, B, and C. there
are also three areas marked with an X that correspond to the distance from each
station that the epicenter was determined to be.
2. Place the compass point on station A and set the pencil point on the area AX.
Using the compass draw an arc or circle (whatever fits) around A. Repeat this
procedure with B and BX and C and CX.
3. Circle and highlight the area where all the lines intersect. This corresponds to the
epicenter. You may not have them all together exactly but the closest you come
will indicate your epicenter. Remember there is only one epicenter per
earthquake. There is only one epicenter in any given earthquake.
4. Repeat this procedure for maps 2 and 3. These are two more earthquakes.
5. Answer the analysis questions.
LAB TOPIC: Using Time Travel Curves to Locate Epicenters 22 points
NAME: _______________________________
DUE DATE: ___________
Analysis (See your text for information about time travel curves.)
Please remember that you are not just answering these questions. You are writing a lab
report and you start with this information and expand on it. Things like time travel curves
should be explained and linked to how the epicenters are determined.
Scroll all the way down to see the 3 maps you are using.
What do the areas indicated by X (AX, BX, CX) represent?
Explain how this information is usually obtained. Include recording station
usefulness and how many are used.
How many recording stations would give the best information? Is there a set
number or can it vary?
Should seismograph stations be located only near fault zones? Why or why not?
LAB TOPIC: Convection Currents
Read through the entire lab before beginning.
Introduction
In this experiment we will study how convection cells are formed in the Earth’s
asthenosphere. This layer has a fluid quality because it is heated from the inside by the
Earth’s core. The area that is closest to the Earth’s crust cools because it is further away
from the heat source. The molecules that make up any form of matter are generally closer
together when cold and further apart when hot. Because of this cold matter is denser and
will tend to sink. Matter that is warm is less dense and tends to rise. This concept will
hold true for liquid magma, water, and air. Therefore the fluid magma nearest to the crust
sinks and the fluid magma that was closer to the core rises. This sets up a current of
magma and helps to explain why the tectonic plates of the crust are moved.
Materials
Ice cubes (4-5)
Pitcher
Large mouth clear liter jar (like a wide top mason jar used in canning)
Small clear jar (like a baby food jar)
Very warm tap water
Green or blue food coloring
Aluminum foil (4-inch square)
Rubber band
Pencil
Procedure
1. Place the ice cubes in the pitcher and fill it with cold water
2. Fill the small jar to the brim (we don’t want air bubbles in here) with very warm
water (not boiling as it will break when placed inside the cold water jar). Add
about 10 drops of food coloring and stir.
3. Carefully cover the small jar with the aluminum foil and secure it in place with a
rubber band.
4. Place the small jar inside the large jar.
5. Remove the ice cubes from the pitcher and poor the cold water into the large jar
filling it about three fourths of the way. Don’t pour directly on the small jar and
make sure that the small jar is completely submerged
6. Using the point of the pencil, make a small hole a bit off center in the foil.
7. From the side observe the contents of both jars for about 10 seconds. Note if any
colored water leaves the small jar or if it stays inside the jar. If it doesn’t leave the
jar make a second small hole as you did previously.
8. Again observe what happens. Look for any movement of colored water into the
larger jar. Observe the contents every five minutes for 20 minutes.
(Remember to answer in complete sentences with correct grammar and spelling.)
Do not return the lab assignment to me. Just submit your report. You can copy the
materials and procedure from the instructions if you wish.
20 points
These questions are to help you write your report. You are not just answering questions.
This is not a worksheet but a report.
Observations (This should be in paragraph form. It will take more than 2 sentences to
report your observations.)
Describe what happened when you made the hole or holes.
Describe fully what happened over the 20 minutes of your observations.
Analysis (This should also be in paragraph form. The questions posed are to help you
formulate your analysis of what occurred.)
Describe what types of movement hot and cold materials undergo.
Explain the reasons for what you observed over the 20 minutes you were watching
the colored water’s movements. Be sure to use scientific terms that apply and define
them.
Account for how this model shows the movement of convection currents. Read about
these in you textbook. Explain why your model cannot keep the currents going as
they do in the Earth’s crust. (Be careful not to plagiarize; rather tell in your own
words what happens that keep convection cells going.)
Boundaries Study Assignment
Answer the questions below and return this worksheet but not the diagrams.
Name and define the type of boundary in the given diagram.
1. a.
22 points
b.
c.
2. What formation is created in the rift of a spreading sea floor?
3. What is formed, besides a trench where an oceanic plate begins to move down in
a subduction zone?
4. When continents collide, rock layers are folded and produce what landforms?
5. What phenomenon might occur when 2 plates move past each other or move into
each other?
6. What type of boundary is at the San Andreas fault?
7. What two major plates meet at the San Andreas fault?
8. What process is believed to be responsible for the movement of the tectonic
plates? Explain the process.
Earthquake Waves 20 points
Reading a Seismogram
Label the P-waves, S-waves, and Surface waves, on or above the diagrams below and
then answer the questions. Note there is only one set of P-waves, S-waves and surface
waves on each seismogram.
Station A
Station B
5
10
15
20
25
Time in Minutes from start of Earthquake
30
1. Describe each type of seismic wave. Be sure to include how they move, through
what kinds of materials, and speed. 4 pts each
a. P-wave:
b. S-wave:
c. Surface wave:
2. Was the epicenter closer to Station A or to Station B? Explain your answer.4 pts
3. At which station was the greatest intensity of the quake felt, A or B? Why do you
make this assumption? 4 pts
NAME: ____________________________
DUE DATE: __________ 32 points
Complete the chart below about five intrusive features formed by volcanoes. 2pts each
Intrusive
Description
Feature
Pluton
Dike
Stock
Batholith
Sill
1
Complete the chart below about the three main categories of volcanoes.
2 pts each
Category
Example (Name one
specific volcano)
How Does the Cone Form
Cinder Cone
Shield Cone
Composite
Cone
2
Matching. Match the words in column A with the definition or descriptions in column B.
1 pt. each
_____ 1. Hawaiian Islands
A. Lava that forms smooth ropey ridges
_____ 2. Flood basalt
B. A chain of subduction zones that encircles the Pacific
Ocean
_____ 3. Caldera
C. A chaotic mix of volcanic ash and rock
_____ 4. Crater
D. Fluid magma that flows on the Earth’s surface
_____ 5. Pahoehoe
E. A feature created by a fissure eruption
_____ 6. Fissures
F. The collapsed roof a magma chamber
_____ 7. Ash-flow tuff
_____ 8. Ring of Fire
G. Explosive ejection of liquid magma and solid
rock
H. Islands formed above hot spots
_____ 9. Pyroclastic eruption
I. Bowl shaped depression at summit of a volcano
_____ 10. Lava
J. Cracks in land surfaces that can ooze magma
3
EXAMPLE LAB REPORT
This is a sample lab to help you understand how to do your lab reports.
LAB TOPIC: Sedimentation
Sedimentary rock is often formed when weathered rock settles to the bottom of
rivers, lakes, and oceans. We will recreate this in a model.
Hypothesis: If the particles are larger, they will settle to the bottom of the container first.
Materials:
Sand
Flour
Water
Baking pan
Procedure
1.
2.
3.
4.
5.
6.
Mix ¼ cup of san with one cup of water.
Stir the mixture well.
Pour this into the baking pan and let it sit for 1 hour.
Mix ¼ cup flour with 1 cup water.
Mix this well and gently pour into the standing water in the baking pan.
Let this sit for another hour.
Observations
Describe what the mixture of sand and water looked like before you poured it into the
pan. Describe what it looked like after an hour. Describe the flour mixture before you
poured it in the pan. Describe what the pan looked like after the second hour.
Analysis
Why did sand and water change in appearance? Why did the flour and water change in
appearance? Account for what happened. How would you relate this to sedimentation in
water bodies on the Earth?
Here’s an example lab report.
The lab I posted are your instructions and should not be submitted as part of your report.
Sedimentation Lab
Introduction
Sedimentary rocks form when layers of sediment are covered by more layers of
sediment and over geologic time are compressed. This pressure causes them to harden
into rock.
Hypothesis: If the particles are larger, then they will settle to the bottom of the container
first.
Materials:
Sand
Flour
Water
Baking pan
Procedure
1.
2.
3.
4.
5.
6.
Mix ¼ cup of san with one cup of water.
Stir the mixture well.
Pour this into the baking pan and let it sit for 1 hour.
Mix ¼ cup flour with 1 cup water.
Mix this well and gently pour into the standing water in the baking pan.
Let this sit for another hour.
Observations
When I first mixed the sand and water it had the appearance of silt laden water.
The sand appeared well distributed through the cup. After the hour elapsed the mixture
was different. All the sand had settled to the bottom of the pan and the water over it
looked almost clear. The same thing seemed to happen with the flour. At first the mixture
was cloudy and the same throughout. After another hour passed I could see the flour had
settled out on the sand at the bottom of the pan. The water over this was again almost
clear. The flour seemed to settle among the sand grains and not form a separate layer of
flour.
Analysis
Both the sand and flour formed mixtures with the water but because they were
mixtures they did retain their own identities. The sand was still sand and the four was still
flour. Because of their weight they settled out of the water once the water was stilled. I
imagine many things would react the same, gravel and water, sugar and water, etc.
Rivers carry much debris as they flow towards a larger body of water. These are a result
of rocks breaking down in the process of weathering. The heavier objects would probably
settle out first and then the lighter ones. As rivers enter larger bodies of water the flow
slows enough that much of what they carry settles out or precipitates. Over time the
constant influx of materials builds up and the pressure on the bottom layers causes them
to form sedimentary rocks.