Chapter 7 & 8
Plate-A slab of the earths lithosphere that can move around.
Boundaries
Ocean
Theories
Uniformitarianism- It is the saying that the present is the key to the past.
People
plate boundary- where two plates meet.
Convection currents and hotspot- A convection current is what moves the plates and a hot spot is a spot where magma rushes up and sometimes causes a volcano.
Lithosphere- the layer that is a mix of the crust and the mantle.
Alfred Wegner- came up with the theory the continental drift.
Harold Hess- supports the thoery of the continental drift with seafloor spreading.
Maps
topographical- a map showing the elevation of the ground.
Geological- a map that shows the different kinds of rocks on the surface.
bathymetric- a map with the sea level and surface of the ocean.
Transform plate boundary- when two plates slide across one another.
Divergent plate boundary- when the plates go opposite directions and away from each other.
Convergent plate boundary- when two plates go head on and there are three types
oceanic-continental is when a ocean and continental plate collide
continental-continental is when two Continental plates collide and usually make a mountain
oceanic-oceanic when two oceanic plates hit
trench- the deepest parts of the ocean.
seafloor spreading-The fromation of new seafloor crust is caused by magma pushing upward and outward on the earths mantle.
Echo sounding- A way to how deep the ocean is and to find trenches and ridges.
Mid-ocean ridge- has the youngest rock and is where sea floor spreading occurs to help replenish the rock that was removed from
subduction.
Continental drift theory- states that the continents were once together and created a super continent called Pangaea then it drifted apart and came to be what it is now..
Plate tectonics theory- It states that earths plates are moving and there moving cause of convection currents and its also moving the worlds continents