Stress and Plate Boundaries
Faults
Seismic Waves
Grab Bag
Volcanoes
100
What is a break in the crust where slabs slip past each other?
A fault.
100
Anticlines and synclines are both types of _______.
Folds
100
What is the machine that measures earthquake waves called?
Seismograph
100
When the rock forming the hanging wall slides up over the footwall, which type of fault is formed?
Reverse
100
The force that causes magma to erupt at the surface is caused by ________________.
The force that causes magma to erupt at the surface is caused by the gases dissolved in the magma being under pressure. (Pressure is released and gas escapes. The magma comes up out of the volcano with the gases.)
200
This type of stress pulls on the crust and stretches it.
Tension
200
Copy and paste this link into a new tab: https://drive.google.com/open?id=0B-gZkTZrCEg7N1RwWWROaVRBVjg In the picture, which side is the hanging wall? Which side is the footwall?
Footwall = left Hanging wall = right (The footwall is NOT ALWAYS on the left, just in THIS picture.)
200
Which type of earthquake wave arrives first at a seismograph?
P waves
200
Copy and paste this link into a new tab: https://drive.google.com/open?id=0B-gZkTZrCEg7dFI2N0tLcmVoc1U What is the amplitude of the earthquake in this seismogram?
160 mm
200
What is the difference between magma and lava?
Magma is underground, and lava is on the surface.
300
Any change in the volume or shape of Earth's crust is called ______________. Stress, folds, and faults are all examples.
Deformation
300
Which type of "wall" is above the fault?
Hanging wall
300
What does the S-P interval on a seismogram tell us?
It indicates the distance that the seismograph is located from the epicenter. (epicentral distance)
300
Why do we need three sets of seismogram data (epicentral circles) to determine an earthquake's epicenter?
Using only two circles would make the possible area of the epicenter too large. Three circles narrows the possible location so that it can be pinpointed more accurately.
300
What is a hotspot?
A hotspot is where magma has melted through the crust in the middle of a plate, not at a plate boundary.
400
What type of stress occurs at a transform boundary?
Shearing
400
When the hanging wall moves downward, this type of fault occurs.
Normal Fault
400
Which state(s) of matter can P waves travel through? Which state(s) of matter can S waves travel through?
P waves can go through solids and liquids. S waves can only go through solids; they cannot go through liquids.
400
Why is the Moment Magnitude Scale better to use than the Mercalli Scale?
The Moment Magnitude Scale can be used to rate earthquakes of all sizes, whether they are closer or far away because it estimates the total energy released by the earthquake. The Mercalli scale is not precise. It indicates the amount of damage in an area and the same earthquake could have different ratings in different locations.
400
What do we call a volcano that is erupting or has shown signs of erupting in the future?
An active volcano
500
What type of stress occurs at the Mid-Atlantic Ridge?
Tension
500
Copy and paste this link into a new tab: https://drive.google.com/a/s.bcsoh.org/file/d/0B-gZkTZrCEg7czdOanVDSUdIMnc/view?usp=sharing Look at the types of stress shown in picture B, C, and D. Which type of fault occurs at each type of stress?
B (shearing) = strike-slip fault C (tension) = normal fault D (compression) =reverse fault
500
Describe how P waves and S waves vibrate as they travel through earth's interior.
P waves compress and expand like an accordion. S waves vibrate from side to side and up and down.
500
How do earthquakes cause tsunamis?
The plate movement during an earthquake causes the ocean floor to rise slightly, and pushes large amounts of water out of the way. This creates large waves that get closer together and higher as they near the shore.
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