Geology (Midterms) Flashcards
is grounding shaking caused by the sudden and rapid movement of one block of rock slipping past another along fractures in Earth’s crust
Earthquake
fractures in earth’s crust called
faults
it tends to occur along pre-existing faults where internal stresses cause the crustal rocks break into two or more units
earthquake
the location where slippage begins
hypocenter or focus
the point on Earth’s surface directl above the hypocenter
epicenter
a form of energy that travels through the lithosphere and earth’s interior
seismic waves
the energy carried by these waves causes the material that transmits them to shake
seismic waves
The famous San Francisco Earthquake
What energy is released that can generate earthquake - like waves
volcanic eruptions, massive landslides, and meteorite impacts
it have been discovered thousands of meters above sea level
fossils of marine organisms
he conducted a landmark study following the 1906 San Francisco earthquake
Harry F. Reid
it was accompanied by horizontal surface displacements of several meters along the northern portion of the San Andreas Fault
San Francisco earthquake
it keeps the fault from rupturing and slipping
friction resistance
a series of earthquake waves radiate outward as it slides
snap back
numerous earthquakes if lesswe magnitude that ahpoen after the strong earthquale
aftershocks
result from crust along the fault surface adjusting to the displacement caused by the main shock
aftershocks
small earthquakes which often, but not always, precede major earthquakes by days or, in some cases, several years
foreshocks
three types of faults
normal fault
reverse fault or thrust fault
strike-slip fault
block of rock below the fault
foot wall
block of rock about the fault
hanging wall
a fault wherein the hanging wall moves down relative to the foot wall
normal fault
a fault wherein the hanging wall moves up relative to the foot wall
reverse fault
thrust fault
a fault wherein two blocks of rocks slide past one another
strike-slip fault
mos of earth’s strongest earthquakes occur along large faults associated with _
convergent plate boundaries