FEB 29 Flashcards
the ring of fire in on a
plate boundary
what is an earthquake
a rapid release of energy
hypocenter def
focus, is the location where the fault slip occurs, it usually on fault surface
epicenter def
a land surface directly above the hypocenter, maps often portray the location of epicenters
hypocenter is _____ ground
below
epicenter is ______ ground
above
faults are
planar breaks in the earths crust
footwall is the
block below the fault
hanging wall is the
block above the fault
the fault scarp is
the chunk of rock that is exposed after a fault
the footwall moves ____ in relation to the headwall (in a regular fault)
rises up
the headwall moves ___ in relation to the
footwall (in a regular fault)
falls down
in a reverse fault the hanging wall moves _ in relation to the footwall
rises up
types of reverse faults
regular reverse fault
thrust fault
strike slip fault
strike slip faults tend to be
more vertical
to types of strike slip faults
right lateral fault
left lateral fault
the displacement of a strike slip fault is
how much this particular earthquake shifted the land surface
the displacement of a normal/reverse fault can be measured by the
length of the fault scarp
active faults generate
earthquakes
inactive faults aren’t
likely to slip
the cobequid-chedabucto fault system is
an inactive fault
active faults generate at
plate boundaries
collision zones and rifts
how do faults form
tectonic forces add stress (pull, push, or shear) to rock
as stress is added to a rock it ends slightly without breaking (elastic strain)
stored elastic energy is released all at once, creating an earthquake
when the stress on a rock is greater than the friction keeping it in place
a fault slip happens
p waves are also called
pressure waves
L waves are
s waves that intersect the land surface
R waves are
p waves that intersect with the land surface
R waves are also called
rayleigh waves
L waves are also called
Love waves
s waves are also called
shear waves
to measure earthquake waves we use a
seismograph
earthquake scale is measured in what two ways
the severity of the damage (intensity)
amplitude of waves at a given distance (magnitude)
issues with the intensity scale of earthquakes is
subjective and often misreported
in a richter scale amplitude is measured by
amplitude of the largest s waves 100km from the epicenter
p waves move faster and are picked up by seismographs
first
the time between P and S waves tell you
how far away the epicenter is
the MW magnitude scale is not
linear
its also not the richter scale
chile 1960 earthquake was
the largest ever recorded
MW amount 9.5
divergent mid ocean ridges cause what kinds of fault
strike slip faulting and normal faulting
convergent plate boundaries cause what kinds of fault
normal faults
reverse faults
megathrust faults
dangerous earthquakes are how deep
shallow
convergent plate boundaries have how deep earthquake
shallow
intermediate
deep
continental transform boundaries cause what kind faults
strike slip faults
continent rifts cause what kind of faults
normal faults
in orogenic crustal compression (mountain building) what kinds of faults occur
normal faults
megathrustal faults
strike slip faults
reverse faults
s waves cause buildings to have a
back and forth motion
p waves cause buildings to have a
up and down motion
R waves and L waves are ____ dangerous than P and S waves
more
on loose sediment earthquakes can induce
landslides and avalanches
liquefaction happens when
an earthquake causes waterlogged sand to become a quicksand
undersea faulting can be dangerous to coastal communities when it forms a
tsunami
faults cause tsunamis by
lifting up the water on the headwall causing a water ripple effect that is a massive wave
as tsunamis get closer to the shore
they grow larger
tsunamis travel at what speed
up to 800km/h
tsunamis have a wavelength of
10s-100s of kilometers
tsunamis have a ___ wave height
low typically under a 100ft
highest tsunami ever was how tall
1700 ft
in alaska
indonesia 2004 earthquake specs
9.3 MW
subduction zone
230,000 dead
caused a tsunami
moved sea floor by 10’s of cm
haiti 2010 earthquake specs
7.0 MW
strike slip
230,000 dead
no tsunami
caribbean plate sudbucted beneath the american plate
japan 2011 earthquake specs
9.0 MW
megathrust
philippine, eurasian and pacific plate
tsunami caused nuclear reactor failure fukushima
20000 deaths
turkey 2023 earthquake specs
anatolian, indian , eurasian and arabian plates
