earthquakes, faults, and folds Flashcards
the focus is…
the location underground where the initial movement occurred
the epicenter is…
the location on the ground surface directly above the focus
At subduction zones, earthquakes can be mapped according to…
their depth
The direction
(or angle) of subduction is indicated by…
the direction of shallow to deep epicenters on a map
There are two kinds of seismic waves…
P waves and S waves
P waves…
primary waves, compressional waves, travel faster than S waves (arrive first at a seismic station)
S waves…
secondary waves, shear waves;
Plate tectonic movement (convergence, divergence, and transform) causes…
increased pressure on the rocks
this pressure is called…
stress
The three kinds of stress are:
compressional, tensional, and shear
Rocks react to stress by deforming, also known as…
strain
the two main types of strain observed in rocks…
Plastic and brittle
because of these types of strain…
Rocks are folded or faulted
