Answer Key

Discussion and Hyperstudio Questions




Lesson 4 "Earthquakes-The Rolling Earth"


Thought and Discussion Questions

1. Describe in your own words what a fault is.
A fault is a long crack in the crust of the Earth. They can be associated with plate boundaries or can be produced from earthquakes.

2. How is a strike-slip boundary different from a convergent and divergent boundary?
A strike-slip boundary occurs where two plates are sliding past each other in opposite directions. It is like a tear in the crust of the Earth.
A convergent boundary occurs where two plates collide. Sometimes one plate is driven under the other, other times the two plates force themselves up into high mountains.
A divergent boundary occurs where two plates are separating. The two plates are moving in opposite directions causing new crust to be formed. These occur at mid-ocean ridges.

3. What is a tsunami?
A tsunami is a very large sea wave. These waves can be up to 100 feet high when they break on the coastline.
4. How does a tsunami form?
Tsunamis are caused by 1) an earthquake 2) an underwater landslide 3) or a volcanic eruption.
Hyperstudio Questions
1. How are earthquake waves produced?
When an earthquake occurs the energy produced from the movement of the plates of the Earth radiates out from the focus in the form of seismic waves.

2. What does a Richter Scale show?
The Richter scale is a measure of the strength and length of time that earthquake lasts.

3. What are the differences between compression, shear, and surface
waves?
Compression waves are the fastest waves produced from an earthquake. Because of their speed they arrive at the surface first and are also called P (Primary) waves. They hit the surface with a pounding or jackhammer motion.
Shear waves are about half the speed of P waves. They arrive later and thus called S (Secondary) waves. They hit the surface with a rolling, up and down motion.
Surface waves are the last waves to strike the surface and are confined to the upper layers of the Earth. The are the slowest waves and cause the most damage. There are two kinds of surface waves Love and Rayleigh waves.



Lesson #5 Volcanoes
Discussion Questions #5
1. What caused the death of so many people during the second eruption of Vesuvius?
The pyroclastic flow of very hot steam, gas, and ash. The flow was probably over 700 degrees and moving at a rate of over 70 miles per hour.
2. What is a pyroclastic flow?
A very turbulent mixture of steam, gases, ash, and small pieces of rock that is heavier than air and moves at a high rates of speed. Some pyroclastic flows are over 900 degrees F. with speeds in excess of 100 miles per hour.

Hyper Studio Questions #5
1. Where do volcanoes form?
Volcanoes form at subduction zones, mid-ocean or rift zones, and at hot spots
2. What are the two definitions for the term volcano.
1) A volcano is an opening in the Earth's surface in which molten rock called magma and gases can escape. 2) The mountain that is formed by repeated volcanic eruptions.
3. Write definitions in your own word for the following terms:
a) Active Volcano-A volcano that is currently erupting or has erupted in recorded time.
b) Dormant Volcano-A volcano that is not currently erupting but has erupted in recorded time and is considered likely to do so again.
c) Extinct Volcano-A volcano that has not erupted in recorded time and is not likely to do so.

Lesson #6 Volcanic Terms
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Hyperstudio Questions
Label the following parts of a volcano by writing your answers on a sheet of paper.
A. Magma Chamber
B. Dike
C. Side Vent
D. Conduit
E. Crater
F. Layers of lava and ash

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