Download Earth Structure

GEOLOGY STUDY GUIDE
Module exam GL1 June 2005
EARTH’S STRUCTURE
Geology Department, Greenhead College, Huddersfield.
Your name .....…………………….................................................
Date .........……………...........
LEARNING TARGETS
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When you have completed this study guide, you will:
● know about the structure of the earth
● understand the movement of earthquake waves
● know about the evidence geologists use to find out about the earth
● have researched your own example of an earthquake
● learnt many useful geological terms.
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VC/Dept/Geol/009
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GEOLOGY STUDY GUIDE
Module exam GL1 June 2005
Resources
Here is a choice of resources to use. You do not need to look at them all but clearly the more you read the
better your knowledge of case studies will be. Tick the box once you have used the resource.
If you read a photocopied extract then highlight it to help you reread it for revision. If you make notes
from a video tape make sure that the notes are headed with the name of the tape so that you know the
source of your information
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ES1
ES2
ES3
ES4
ES5
ES6
ES7
ES8
ES9
ES10
ES11
ES12
ES13
ES14
ES15
ES16
ES17
Understanding Geology David Webster p 9-13
Geoscience Edwards and King p.21-31
Geological Science by Andrew McLeish p.115-128
Earthquakes HMSO booklet in Thordur Centre – extract on Richter and Mercalli scales
Handout on earthquake focus and epicentre Sheet 5
Isoseismal map
Video Seismology at Work. Tapes 3, 4, 5, 6, 7, 13 Alaskan earthquake 4.5 mins - watch
twice
Activity sheets 7 and 8 on refraction and reflection of earthquake waves
Activity 28 and 31 on travel time curves – Plotting the Epicentre
Summary Table on Earth composition and structure
Earth Story Programme 8 A World Apart 50 mins Library video and Tape 41
Structure of the Earth. New Scientist Feb 1988
Graph of Velocity/Depth curves
Hutchinson R. and Graham A. Meteorites HMSO Library
Video Meteorites Tape 18 10 mins
Diagram to show paths of earthquake waves
Skinner, B.J. and Porter, S.C., The Dynamic Earth Chap 15 Library
Websites
www.geolsoc.org.uk/ Go to Teaching Resources
www.gsrg.nmh.ac.uk/
www.earthquake.usgs.gov/
www.iris.washington.edu/seismic/60_2040_1_8.html
www.gps.caltech.edu/~polet/events90-96.html
www.geo.arizona.edu/saso/Earthquakes/Recent/
There are many other websites you could search.
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GEOLOGY STUDY GUIDE
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Module exam GL1 June 2005
TASK 1 EARTH’S STRUCTURE
The earth has a layered structure of crust (two main types), mantle, outer and inner
core, each layer having a distinctive thickness, composition, density and physical
state. Write notes using your textbooks (ES 1, ES 2 and ES 3) about each layer in
the earth.
TASK 2 EVIDENCE USED TO DISCOVER ABOUT THE EARTH
Discuss with your group about how scientists can find out about what is inside the
earth. Draw a spider diagram or mindmap in your group to show your ideas.
TASK 3 EARTHQUAKE SCALES
You will have established that earthquake (or seismic) waves are the most
important evidence used by scientists. Using ES 1 and ES 4 describe the two
scales which measure the magnitude and the intensity of earthquakes. What are
the main differences between the two scales?
TASK 4 FOCUS, EPICENTRE AND ISOSEISMALS
Using the handout ES 5 label the focus, epicentre and isoseismals. Check your
textbooks for definitions of each to make sure that you know what they are.
Use ES6 to draw the isoseismal map for an earth quake.
TASK 5 EARTHQUAKE WAVES
 Find a way of demonstrating how P, S and L waves move through the earth.
 Write a note to yourself to remind you about the differences between the three
types of waves. You can use diagrams, tables or a written account of each type
of wave.
 Draw a seismograph to show arrival times of P, S and L waves at a seismometer
station
TASK 6 ALASKAN EARTHQUAKE 1964
Watch ES 7 twice. Comment on the earthquake’s origin and the effects it had.
What was the magnitude and intensity of the Alaskan earthquake? Make further
notes from ES 4 if you would like to find out more.
TASK 7
Research a specific earthquake using any resources you can find. The internet has
proved to be very popular in the past to find out about recent earthquakes but there
are many books and videos in the Library to borrow. Find out about the magnitude
and intensity of the earthquake and the effects it had. Maps and photographs help
with your explanation
Use this box for notes
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VC/Dept/Geol/009
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GEOLOGY STUDY GUIDE
Module exam GL1 June 2005
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TASK 8 MOVEMENT OF WAVES THROUGH THE EARTH
Waves can be reflected and refracted as they travel through the earth. Carry out
Activities 7 and 8 on ES 8 to show how these processes work.
TASK 9
VELOCITY/DENSITY CHANGES AND THE STRUCTURE OF THE
EARTH
 Draw the graph from ES 3 p.123 which shows how velocity of P and S waves
changes as waves pass into the centre of the earth.
 Summarise in bullet points what the graph tells you about P and S waves.
Identify and label the Low Velocity Zone (LVZ) which is also known as the
asthenosphere.
 Use ES13 to label layers within the Earth.
TASK 10
Draw the graph from ES 3 p.124 which shows how density of each layer changes.
On your graph label the main layers and discontinuities within the earth.
TASK 11 DISCONTINUITIES
Find the best definition of a discontinuity by checking through your textbooks.
There are two main discontinuities within the earth, so identify which layers they
separate and the changes in densities and composition which take place at the
discontinuity. Label the discontinuities on the graph you drew for Task 9.
TASK 12 WHAT EARTHQUAKE WAVES DO AS THEY TRAVEL THROUGH
THE EARTH
Use ES16, which shows how earthquake waves curve as they pass through the
earth, and explain how the P and S wave shadow zones occur. Draw a full page
version with plenty of space for explanations in your own words. Label your
diagram fully, including each layer in the earth, the Mohorovicic and Gutenberg
discontinuities, the importance of the epicentral angles and the two shadow
zones.
TASK 13 TRAVEL TIME CURVES – PLOTTING THE EPICENTRE
Complete the exercise ES 9 Activity 28 and 31 on travel time curves. You will
need a drawing compass to finish this accurately.
TASK 14 METEORITES
Meteorites have provided very valuable information on the composition of the
earth. Read about them in your textbooks. Learn about the two main types – stony
meteorites and iron meteorites - and what they tell us about the composition of
the mantle and the core.
Use this box for notes
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VC/Dept/Geol/009
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GEOLOGY STUDY GUIDE
Module exam GL1 June 2005
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TASK 15 OTHER EVIDENCE FOR EARTH STRUCTURE
Make notes on the evidence given by hot springs, mantle rocks at surface, deep
bore holes, volcanoes, the earth’s magnetic field and meteorites.
TASK 16 SUMMARY OF EARTH STRUCTURE
Now fill in the table ES 10 which summarises the thickness, composition, nature
and density of each layer. This table is a way of reminding yourself what you know
about earth layers and what evidence geoscientists can use in the study of the earth.
TASK 17
GLOSSARY
This topic contains plenty of geological jargon. Here is a list of words that you need to be
familiar with. Write out their definitions to help with your long-term learning.
Isoseismals
Asthenosphere
continental lithosphere
iron meteorites
shadow zone
refraction
outer core
Richter Scale
oceanic lithosphere
time-travel curves
discontinuity
mantle
reflection
epicentre
Mercalli Scale
focus
stony meteorites
Mohorovicic discontinuity
epicentral angles
inner core
Gutenberg discontinuity
TASK 18
SUMMARY NOTES
You need to learn this topic now.
Summary notes deadline……………………………………
Use this box for notes
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VC/Dept/Geol/009
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