Plate tectonics Flashcards
Lithosphere
The outermost rigid layer of the earth
Asthenosphere
Is the plastic layer of the mantle on which pieces of lithosphere move.
Mesosphere
The strong lower part of the mantle between the asthenosphere and the outer core.
Outer core
Is the liquid layer of the earths core that lies beneath the mantle and surrounds the inner core.
Inner core
The solid dense center of our planet that extends from the bottom of the outer core to the center of the earth.
Density
Mass of a unit volume of a material substance.
Alfred Wegener
Proposed the theory of continental drift, the idea that earth’s continents move.
Seismic waves
A wave of energy that travels through the earth and away from an earthquake in all directions.
Oceanic crust
The thin outer layer of the earth which makes up the rocky bottom of the ocean basins.
Convergent boundary
The boundary formed by the collision of two lithospheric plates
Divergent boundary
The boundary between two tectonic plates that are moving away from each other.
Transform boundary
The boundary between tectonic plates that are sliding past each other horizontally.
Sea- floor spreading
The process by which new oceanic lithosphere forms as magma rises towards the surface and solidifies.
Pangaea
A hypothetical continent including all the landmasses of the earth.
Laurasia
A hypothetical continent that broke up later into North America, Europe and Asia.
