Earth Systems
this sphere contains all the liquid on earth
Hydrosphere
Contour lines
Plates moving apart is called a _______ boundary
Divergent
Point beneath earth’s surface where slippage occurs
focus (hypocenter)
Science often begins with this
observation
This sphere contains the earth’s magnetic field
magnetosphere
The change in elevation between adjacent contour lines
contour interval
Stress most associated with transform boundaries
Shear stress
Point on earth’s surface directly above the focus
epicenter
If the S-P lag time is bigger, the station is (closer/farther) from the epicenter
farther
The principle that “the present is the key to the past”
Uniformitarianism
Close contour lines indicate this
Steep slope or high gradient
When one plate sinks beneath another
The body wave that arrives first at a station; particles move parallel to wave travel
P-wave
Saturated sediments can behave like a fluid during shaking
liquefaction
A testable, tentative explanation for an observation
Hypothesis
Hachurged contour lines represent this feature
A depression
Plate boundaries where the largest earthquakes often occur (hint: big locked faults)
Convergent (especially subduction zones)
The body wave that arrives second; particles move perpendicular to wave travel
S-wave
Rule of V’s: the “V” in contour lines points __________ when crossing a stream valley
Upstream (toward higher elevation)
Convert 315,000 years to Ka
315 Ka
If elevation changes 300 m in 6 km, calculate the gradient
50 m/km
Earthquake locations worldwide often “trace” this global pattern
tectonic plate boundaries
Method using distances from at least three stations (circles on a map) to locate the epicenter
triangulation
Tsunamis are most often caused by major offset along a fault at what type of boundary, and the fault must be where?
Convergent/subduction boundary; fault must be underwater (seafloor displacement)