3 sources of earth's heat?
radioactive decay, primordial heat, and solar energy
raft like structure floating on mantle
below lithosphere, drawn up into mid-ocean ridge
convection creating trade winds
types of plate boundaries
divergent, convergent, transform
plate boundary that's generally non-threatening because of the hot, thin brittle zone
plate boundary that requires great amounts of energy because of the cold, thick brittle zone and shallow angle
plate boundaries slide past, but get stuck at irregularities and bends- generally moderate to warm with a modest brittle zone
what indicates continental shift?
magma magnetized by Earth's magnetic field
two types of faults
dip-slip and strike-slip
two types of Dip-slip faults and their dominant force
normal-extension and thrust-compression
in a strike slip fault, if you are standing on one side and the other side moves left, you have a...
left lateral fault
plates moving at the same rate/direction
point directly above hypocenter on surface
earthquake first occurs at this point
study of earthquakes and earthquake waves
two types of seismic waves
body waves and surface waves
two types of body waves (fastest to slowest)
P and S
body wave that is first to arrive, faster through more solid
body wave that is 2nd to arrive; does not go through liquid or gas
slower seismic waves, more concentrated on the surface
surface wave that moves up and down and side to side (like the ocean)
surface wave that moves side to side and makes building fall
hot stuff goes up, cold stuff goes down- involved with sun, rain, and mantle
subducting cold plates make the planet...?
cool off faster
Three ways to measure magnitude:
Richter, Seismic moment, Mercalli Scale
What determines the magnitude of an earthquake?
the size of rock being subducted and how cold and brittle the rock is
largest earthquakes found here:
why do subduction zones cause the largest earthquakes?
subduction causes cooling and increases brittle facture; low angle dip means the area of the fault in the brittle zone will be larger
conspicuous area missing earthquakes