Pangaea is: Large, ancient landmass that was composed of all the continents joined together

Theory of PlateTectonics is: Theory that the Earth’s crust and upper mantle are broken into plates that float and move around on a plastic-like layer of the mantle

Continental Drift is: Wegener’s hypothesis that all continents were once connected in a single , large land mass that broke apart about 200million years ago and drifted slowly to their current positions

Sea Floor Spreading is: Hess’s theory that new seafloor is formed when magma is forced upwards toward the surface at the mid-oceanic ridge

Convection current is: Currents in Earth’s mantle that transfers heat in Earth’s interior and is the driving force for plate tectonics

Subsidence is: Motion of the Earth’s surface as it shifts downward relative to a datum such as sea=level

Boundary: Indicates a border

Convergent boundary is: Formed when two sections of Earth’s crust is colliding – coming together

Divergent Boundary is: Forms where lithospheric plates are moving away from each other.

Transform Boundary is: Boundary between two lithospheric plates that are sliding past each other.

Rift is: Long crack that forms between tectonic plates moving apart at plate boundaries

Fault is: Fracture that occurs when rocks change their shape by breaking can form as a result ofcompression, being pulled apart by shear

Subduction zone is: Area in which one lithospheric plate slides under another, occurs at converging plate boundaries

Ridge is: A chain of mountains or hills that form as continuous elevated crest for some distance

Trench is: Depression in the ground, generally defined by being deeper than they are wide.

Asthenosphere is: Plastic-like layer of the Earth on which the lithospheric plates float and move around

Lithosphere is: Rigid layer of Earth about 100 km thick, plates moving apart at plate boundaries

Relief map is: A physical map showing vertical features with a drawing such as shaded mountains

Topography is: Features of a land area caused by differences in elevation.

Topographic Map is: A map that shows the shape and elevation of the land surface using contour lines, and shows other land features using symbols and colors

Contour lines are: On a map, lines that connect point of equal elevation above sea level.

Elevation is: Height above average sea level

Intervals is: Distance between contour lines on a topographic map

Benchmark is: A permanently affixed mark that establishes the exact elevation of a place; used by surveyors in measuring site elevations