earthquakes Flashcards
ring of fire
a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
Strike-slip fault
vertical (or nearly vertical) fractures where the blocks have mostly moved horizontally.
Normal fault
inclined fractures where the blocks have mostly shifted vertically.
Reverse fault
the block above the fault moves up relative to the block below the fault.
P-waves
the fastest seismic waves and can move through solid, liquid, or gas.
S-waves
transverse waves that travel slower than P-waves.
epicenter
the point on the earth’s surface vertically above the focus of an earthquake.
focus
the center of interest or activity.
Richter magnitude scale
each one-point increase on the scale represents a 10-fold increase in the magnitude of the quake.
explosive volcano
depends on the composition of the magma (molten rock) and how readily gas can escape from it.
nonexplosive volcano
appears to result from rapid, sub-surface gas release from magma ascending as a permeable foam.
Krakatoa
one of the deadliest and most destructive volcanic events in recorded history.
Yellowstone supervolcano
is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States.
San Andreas fault
is a continental transform fault that extends roughly 1,200 kilometers through California.
Mid-oceanic ridge
a seafloor mountain system formed by plate tectonics.
