plate boundaries Flashcards
how can you record the earth’s pole
Rocks permanently freeze recording the polarity at the time
What is the force of plate motion
Gravity
slab pull
pull of gravity on a subduciton zone
Divergent
rifting apart
convergent
coming together
transform
sliding past (fault)
avg depth of plates
100km (height of lithosphere)
ridge push
mid ocean ridges pushing apart
subduction
oceanic lithosphere subducting under continental lithosphere
mantle convection
-denser (colder) moves down
-less dense (hotter) moves up
Earthquakes
outline plate boundaries, continents and ocean basin.
-mid ocean ridges do not have many earthquakes
-land that surrounds the ocean
aesthenosphere
melts, rises.
-youngest rocks are in the ridge
light blue on the map
mid ocean ridge (divergent)
furthest rock from plate boundary
Will become dense and subduct
oldest rock
Mid ocean ridges
Atlantic (divergent)
Indian (Divergent)
East Pacific Rise; very active (divergent)
Southwest Indian ridge
Iceland volcanoes
convergent boundaries
earthquakes
volcanic eruptions
subduction zones
landslides
tsunami waves
subduction zones
Can have mega thrust earthquakes
Largest ever recorded was a 9.5 in chile
plates colliding
subduction zones (oceanic plates going down, more denser than continent)
deep sea trenches
are the boundaries at subduction zones
gravity
the force that is being applied to the plate boundary
plates colliding examples
Andes mountains
Japan (fiji mountains)
mt hood, st helen
continent collison
convergent boundaries
2 continents colliding by previous subduction zones
low density continents
cannot subduct, they collide with other continents
ex. Himalayan mountains
can cause organisms from the bottom of the ocean to be in mountains.
(only one continent moves)
california plate boundaries
tranform boundary ex. San Andreas fault