EAPS 106 - 96 Exam 1
How do earthquake early warning systems work? - ✔ ✔ seismic waves travel
below the speed of light; therefore, a warning can arrive seconds before an
earthquake (since EM radiation travels at the speed of light)
Why does the mantle below the asthenosphere not flow easily? - ✔ ✔ it is at
higher pressure than the asthenosphere
Why does the US Geological Survey believe there is high seismic hazard in the
Midwest? - ✔ ✔ historical data from previous earthquakes shows that a 500
year old fault has been reactivated
Why is the Earth layered? - ✔ ✔ differences in density: more dense layers sink
below less dense ones (called differentiation)
Why is the inner core solid despite being hotter than the outer core? - ✔ ✔
the inner core is under higher pressure than the outer core
Why was an Italian seismologist sent to prison in 2012? - ✔ ✔ they didn't
predict any earthquake based on foreshocks; they were released a year later
How do earthquake isolation systems work? - ✔ ✔ buildings are isolated from
ground-shaking by mounting them on isolators made of layers of steel and rubber
that absorb side-to-side motion
How do loose, unconsolidated sediments influence earthquake shaking? - ✔ ✔
they magnify the intensity and duration of the shaking (like Jello)
How do we infer the build-up of stress on a fault? - ✔ ✔ GPS measurements of
the velocity at which plates are moving
How do we know that the outer core is liquid? - ✔ ✔ the discovery of S wave
shadow zones indicating that there was a part of the Earth's interior they could
not propagate through
, How do we know the Earth is not hollow? - ✔ ✔ the rock is too weak at high
temperatures to support voids, the passage of seismic waves shows no voids, the
magnitude of gravity requires a dense, continuous interior
How do we know the inner core is solid? - ✔ ✔ the refraction of P waves as
they cross over the inner-outer core boundary create P and S wave shadow zones
How do we know the magnetic poles reverse? - ✔ ✔ alternating patterns in
the magnetic polarity of volcanic rock
How do we use GPS measurements to estimate earthquake potential? - ✔ ✔
we measure slip-deficit rates which indicate the amount a fault will need to slip
to cause an earthquake
How long after surface waves arrive do poorly constructed buildings generally
collapse? - ✔ ✔ within a few seconds
How many earthquakes occur each year? - ✔ ✔ about 1.3 million
How many seismograms are needed to locate an earthquake? - ✔ ✔ 3
How may have plates tectonics influenced the evolution of whales and dolphins? -
✔ ✔ when India broke off from Africa and moved towards Asia, it created
shallow marshy areas where land animals could slowly become aquatic
How often do large earthquakes occur on the San Andreas fault? - ✔ ✔ about
every 150 years
How should one respond to an earthquake if indoors in a first-world country? - ✔
✔ take cover under a table or load-bearing door frame; stay away from glass
and anything that could fall; don't attempt to go outdoors; don't use elevators
How should one respond to an earthquake if indoors in a third-world country? -
✔ ✔ get out quickly
How should one respond to an earthquake if outdoors? - ✔ ✔ stay outdoors;
get away from buildings
How do earthquake early warning systems work? - ✔ ✔ seismic waves travel
below the speed of light; therefore, a warning can arrive seconds before an
earthquake (since EM radiation travels at the speed of light)
Why does the mantle below the asthenosphere not flow easily? - ✔ ✔ it is at
higher pressure than the asthenosphere
Why does the US Geological Survey believe there is high seismic hazard in the
Midwest? - ✔ ✔ historical data from previous earthquakes shows that a 500
year old fault has been reactivated
Why is the Earth layered? - ✔ ✔ differences in density: more dense layers sink
below less dense ones (called differentiation)
Why is the inner core solid despite being hotter than the outer core? - ✔ ✔
the inner core is under higher pressure than the outer core
Why was an Italian seismologist sent to prison in 2012? - ✔ ✔ they didn't
predict any earthquake based on foreshocks; they were released a year later
How do earthquake isolation systems work? - ✔ ✔ buildings are isolated from
ground-shaking by mounting them on isolators made of layers of steel and rubber
that absorb side-to-side motion
How do loose, unconsolidated sediments influence earthquake shaking? - ✔ ✔
they magnify the intensity and duration of the shaking (like Jello)
How do we infer the build-up of stress on a fault? - ✔ ✔ GPS measurements of
the velocity at which plates are moving
How do we know that the outer core is liquid? - ✔ ✔ the discovery of S wave
shadow zones indicating that there was a part of the Earth's interior they could
not propagate through
, How do we know the Earth is not hollow? - ✔ ✔ the rock is too weak at high
temperatures to support voids, the passage of seismic waves shows no voids, the
magnitude of gravity requires a dense, continuous interior
How do we know the inner core is solid? - ✔ ✔ the refraction of P waves as
they cross over the inner-outer core boundary create P and S wave shadow zones
How do we know the magnetic poles reverse? - ✔ ✔ alternating patterns in
the magnetic polarity of volcanic rock
How do we use GPS measurements to estimate earthquake potential? - ✔ ✔
we measure slip-deficit rates which indicate the amount a fault will need to slip
to cause an earthquake
How long after surface waves arrive do poorly constructed buildings generally
collapse? - ✔ ✔ within a few seconds
How many earthquakes occur each year? - ✔ ✔ about 1.3 million
How many seismograms are needed to locate an earthquake? - ✔ ✔ 3
How may have plates tectonics influenced the evolution of whales and dolphins? -
✔ ✔ when India broke off from Africa and moved towards Asia, it created
shallow marshy areas where land animals could slowly become aquatic
How often do large earthquakes occur on the San Andreas fault? - ✔ ✔ about
every 150 years
How should one respond to an earthquake if indoors in a first-world country? - ✔
✔ take cover under a table or load-bearing door frame; stay away from glass
and anything that could fall; don't attempt to go outdoors; don't use elevators
How should one respond to an earthquake if indoors in a third-world country? -
✔ ✔ get out quickly
How should one respond to an earthquake if outdoors? - ✔ ✔ stay outdoors;
get away from buildings
