Finals Flashcards
Mid ocean ridge
A long undersea mountain chain that has a steep, narrow valley at its center, that forms as magma rises from the asthenosphere, and that creates new oceanic lithosphere (sea floor) as tectonic plates move apart.
Continental Drift
The theory that the continents we know today were once in a massive supercontinent called Pangaea and drifted apart across time to their current positions.
Sea-Floor Spreading
The process by which new oceanic lithosphere (sea floor) forms when magma rises to Earth’s surface at mid-ocean ridges and solidifies, as older, existing sea floor moves away from the ridge.
Paleomagnetism
The study of the alignment of magnetic minerals in rock, specifically as it relates to the reversal of Earth’s magnetic poles; also the magnetic properties that rock acquires during formation.
Relative age of sea floor
Ocean floor is very young
Land rocks are up to four billion years old
Oceanic rocks at most two hundred million years old
Sea floor rocks closer to a Mid-ocean ridge are younger than sea floor rocks farther from a ridge
Plate Tectonics
The theory that explains how large pieces of the lithosphere, called PLATES, move and change shape.
Lithosphere
The solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle.
What is the order of the layers?
Litho
Asthen
Meso
Asthenosphere
The solid, plastic layer of the mantle beneath the lithosphere
Earth’s Magnetic Field
Come back
Convergent Boundary
The boundary between tectonic plates that are colliding
Transform Boundary
The boundary between tectonic plates that are sliding past each other horizontally.
Divergent Boundary
The boundary between tectonic plates that are moving away from each other
Convection
Convection is the movement of heated materials due to differences in material
Ex: boiling water at the bottom of a pot.
Ridge Push
Newly formed rock at a mid ocean ridge is warmer and less dense than older rock nearby. The warmer, less dense rock is elevated above new rock
