Earth Layers
The outermost layer of Earth
Crust
Two plate colliding
Convergent Boundary
The landmass that existed when all continents were joined.
Pangaea
Located on the Pacific Plate
The Ring of Fire
Scale used to rate the San Francisco Earthquake
Richter Scale
Composed of the rigid crust and upper portion of the mantle.
Lithosphere
Two plates scraping past each other
Transform Boundary
The process of new oceanic crust forming as magma rises toward the surface and solidifies.
Sea-Floor Spreading
Have not erupted in recorded history and probably never will erupt again.
Extinct
More destructive seismic waves
Surface Waves
____________ of Earth's surface is composed primarily of water.
75%
Stress that causes plates to thin in the middle due to the pull of a plate in opposite directions.
Tension
The theory that explains how large pieces of Earth’s outermost layer, called tectonic plates, move and change shape.
The Theory of Plate Tectonics
Volcanically active places on Earth’s surface that are far from tectonic plate boundaries
Hotspots
Fault responsible for many earthquakes in California.
San Andreas Fault
Under great pressure due to the weight and gravity of other layers.
Inner core
Effects of an oceanic crust and continental crust colliding and causing crust to be DESTROYED
Subduction Zone
A professor of geology at Princeton University, was very influential in setting the stage for Sea-Floor Spreading.
Harry Hess
Gently sloping hillsides but can be HUGE!
Shield Volcano
A wave of energy that travels through the Earth, away from an earthquake in all directions
Seismic waves
Denser than the crust and mantle, about 2200km thick.
Outer Core
Rift valleys are an effect of this type of boundary.
Divergent Boundary
A German scientist born in 1880, noticed that the continents looked as if they all once fit together.
Alfred Wegener
“Resistance to flow”
Viscosity
90% of earthquakes occur at plate boundaries. 10% occur here.
Middle of a plate/Fault Lines