Earthquake Notes

Question 1

What is an earthquake?

Answer 1

The shaking of the earth’s crust due to a release of energy/pressure along a fault line

Question 2

Fault:

Answer 2

A crack in the earth’s crust where there is movement

Question 3

What do earthquakes result from?

Answer 3

• Movement along a plate boundary
• Volcanic eruptions
• Plates

Question 4

Plates:

Answer 4

A section of the earth’s crust or lithosphere which moves

it includes oceanic and continental crust, either or both

Question 5

Elastic Rebound Theory:

Answer 5

This theory explains movement. It says that strain builds up between 2 sections of crust and deforms them. When the stress overcomes friction, crust shifts and goes back to its original shape (in a new place).

Question 6

Seismic Wave:

Answer 6

How energy travels through the earth from the earthquake

Question 7

Focus:

Answer 7

Point of origin of the earthquake underground

Question 8

Epicenter:

Answer 8

Point of origin of the earthquake on the surface

Question 9

How do we measure earthquake strength or magnitude?

Answer 9

Richter Scale

Question 10

Richter Scale:

Answer 10

Based on powers of ten, calculated from amplitude of highest S-Wave on the siesmogram

Question 11

What does the Richter Scale measure from?

Answer 11

1-10
1=1
2=10x more powerful
3=100x more powerful

Question 12

How do we measure earthquake intensity?

Answer 12

Modified Mercalli Scale

Question 13

Modified Mercalli Scale:

Answer 13

Based upon peoples observations, ranges from 1-12

Question 14

Seismic Waves:

Answer 14

P-Waves
S-Waves
L-Waves

Question 15

P-Wave

Answer 15

first wave, compressional, body wave, travels through solids, liquids and gases

Question 16

S-Wave

Answer 16

Secondary wave, shear, transverse, body wave, travels through solids only

Question 17

L-Wave

Answer 17

Longitudinal, surface wave, p/s convert to this when they reach the surface, two types: Love and Rayleigh Wave