Chapter 13 Flashcards
elastic rebound theory
as the crustal blocks on either side of a fault are deformed by tectonic forces, they remain locked in place by friction until they fracture and rebound to an undeformed state
fault slip
the distance of displacement
recurrence interval
the time between ruptures of the buildup and release of elastic energy
focus
the point at which the fault slipping begins
epicenter
the point on the surface of the Earth directly above the focus
afterchocks
smaller earthquakes after the mainshock
foreshock
small earthquake before the mainshock
seismograph
an instrument that records seismic waves
types of seismic waves
p waves
s waves
surface waves
p waves
primary waves
s waves
secondary waves
surface waves
slower waves that travel around the Earth’s surface
what type of wave is a p wave?
compressional wave - push-pull wave
what can p waves travel through?
solids, liquids or gaseous materials
what type of wave is an s wave
shear waves - displace material at right angle to their path
what can s waves travel through and how fast?
solids only
a little more than half the speed of p waves
fault mechanism
the orientation of the fault rupture anf the direction of slipping
Mercalli intensity scale
assigns a roman numeral (I - XII) to the intensity of the earthquake
what type of faulting occurs at divergent boundaries?
normal faulting
how deep are earthquakes at divergent boundaries?
shallow
what type of faulting occurs at transform-fault boundaries?
strike-slip faulting
at what plate boundary do the largest earthquakes occur?
convergent boundaries
how deep are the earthquakes at convergent boundaries?
the deepest earthquakes occur at convergent boundaries
how deep are intraplate earthquakes?
relatively shallow
what type of earthquakes cause tsunamis?
megathrust events (compressional)
