Earth Science 6th Pangea

Pangea

Ancient landmass made up of all the continents that began to break apart about 200 mya

Continental Drift

Wegener’s hypothesis that Earth’s continents were joined as a single landmass, that broke apart about 200 mya and slowly moved

Continental shelf

Shallowest part of a continental margin, that extends into the ocean from the shore and provides a nutrient-rich home to fish

Continental slope

Sloping oceanic region found beyond the continental shelf that marks the edge of the continental crust

Deep-Sea Trench

Elongated, sometimes arc-shaped depression in the seafloor; is the deepest part of the ocean

Mid-Ocean Ridge

Chain of underwater mountains that run throughout the ocean basins, and can contain active and extinct volcanos

Seafloor Spreading

The hypothesis that new ocean crust is formed at mid-ocean ridges and destroyed at deep-sea trenches

Magnetometer

Device used to map the ocean floor that detects small changes in magnetic field

Magnectic Reversal

When Earth’s magnetic field changes polarity between normal and reversed

Isochron

Imaginary line on a map that shows points of the same age; formed at the same time