Quake Basics
waves of energy that travel through the Earth
seismic waves
at which type of boundary are earthquakes most mild?
divergent
what is a fault?
a break in the earth's crust along which rocks move
What is the focus of an earthquake?
the point inside the earth where an earthquake begins
these waves travel only across the earth's surface
surface waves
true or false: humans notice the majority of earthquakes that happen
false
at what type of boundary does the highest number of earthquakes occur
convergent
Name two types of dip-slip faults
Normal and reverse
What is an epicenter of an earthquake?
The point on the earth’s surface that is directly above an earthquake
The fastest seismic waves
p waves
seismic waves can travel through all layers of the earth, but only affect this layer
lithosphere
This type of earthquake is very common and the most gentle
shallow-focus earthquake
the san andreas fault is what type of fault?
strike-slip
Energy released when plates move travels in the form of
seismic waves
Name the two types of surface waves
Love waves and Rayleigh waves
how do earthquakes occur?
earth's plates or fault blocks bump into each other
At what depths beneath the earth's surface would an intermediate earthquake occur?
70-300 km
What is a dip-slip fault?
A fault where two fault blocks move past each other vertically
the underground point in the crust where built-up pressure between plates is released
focus
p waves can travel through what state(s) of matter?
solid, liquid, and gas
explain how large earthquakes occur
Large earthquakes happen because plates get “caught” on one another. When they finally snap apart, they move quickly
most deep-focus earthquakes occur around which plate?
pacific plate
what is a strike-slip fault?
A fault where two fault blocks move past each other horizontally
Under what depth beneath the earth's surface do deep-focus earthquakes occur?
300 km
These types of waves are the last to leave the focus of an earthquake
surface waves