earthquake/volcano Flashcards
ring of fire
a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
Strike-slip fault
a fault on which the two blocks slide past one another.
Normal fault
a dip-slip fault in which the block above the fault has moved downward relative to the block below.
Reverse fault
the block above the fault moves up relative to the block below the fault.
P-waves
seismic body waves meaning that they travel through the Earth’s interior.
S-waves
the second wave to hit the seismographs.
epicenter
point on the surface of the Earth that is directly above the underground point (called the focus) where fault rupture commences, producing an earthquake.
focus
“a point at which rays of light, heat, or other radiation meet after being refracted or reflected.”
Richter magnitude scale
quantitative measure of an earthquake’s magnitude
explosive volcano
If a lot of gas is trapped within magma, pressure will build and build until eventually the magma erupts explosively out of the volcano.
nonexplosive volcano
generally occur when magma is thin and flows easily.
Krakatoa
a small volcanic island in Indonesia between Java and Sumatra
Yellowstone supervolcano
a volcanic center that has had an eruption of magnitude 8 on the Volcano Explosivity Index
San Andreas fault
a continental transform fault that extends roughly 1,200 kilometers (750 mi) through California.
Mid-oceanic ridge
an elevated region with a central valley on an ocean floor at the boundary between two diverging tectonic plates where new crust forms from upwelling magma.
