Lesson 4 Flashcards
crust
the thin and solid outermost layer of the Earth above the mantle
mantle
the layer of rock between the Earth’s crust and core
core
the central part of Earth below the mantle
lithosphere
the solid, outermost layer of the Earth that consists of the crust and the rigid upper part of the mantle
asthenosphere
the soft layer of the mantle on which the tectonic plates move
mesosphere
the strong, lower part of the mantle between the asthenosphere and outer core
tectonic plate
a block of lithosphere that consists of the crust, and the rigid, outermost part of the mantle
continental drift
the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
sea-floor spreading
the process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies
plate tectonics
the theory that explains how large pieces of the Earth’s outermost layer, called tectonic plates, move and change shape
convergent boundary
the boundary formed by the collision of two lithospheric plates
divergent boundary
the boundary between two tectonic plates moving away from each other
transform boundary
the boundary between tectonic plates that are sliding past each other horizontally
compression
stress that occurs when forces act to squeeze an object
tension
stress that occurs when forces act to stretch an object
