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CMSScience8-Unit10
Term | Definition |
---|---|
Lithosphere | Cool, rigid, outermost layer of Earth divided into enormous pieces called tectonic plates; consists of the crust and the rigid uppermost part of the mantle |
Plate Tectonic Theory | Theory the lithosphere is divided into tectonic plates that slowly move on top of the asthenosphere |
Subduction | A plate is forced below when one plate is denser than another as they converge |
Continental Drift | The theory continents were once connected but have drifted apart |
Contour Line | A line (as on a map) connecting the points having the same elevation on a land surface |
Convergent Boundary | The boundary between two tectonic plates moving toward each other |
Divergent Boundary | The boundary between two tectonic plates moving away from each other; on land creates rift valleys, on the sea floor created new ocean crust |
Elevation | Indicates the height of somehting in relation to sea level |
Pangaea | Hypothetical land area believed to have once connected all landmasses |
Plate | A large piece of the Earth’s crust |
Seafloor Spreading | A parallel pattern of rock material found at identical locations on each side of the Mid-Atlantic Ridge reveals rock of the same geologic age and polarity |
Topographic Map | A map showing changes in elevation of Earth's surface |
Transform Boundary | The boundary between two plates where they slide pass one another; sudden shifts result in major geological events such as earthquakes and the release of stored energy |
Fault | A crack in the lithosphere, resulting from movement |
Trench | A long narrow steep-sided depression in the ocean floor, ocurring at the point of subduction |
Mid-Ocean Ridge | An underwater mountain range, formed by plate tectonics |
Rift Valley | A long valley formed by a divergent boundary, when the sinking of the earth's crust between two parallel or nearly parallel faults or groups of faults |