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8th Science U7 L1
| Definition | Term |
|---|---|
| Hypothesis that a single large landmass broke up into smaller land masses to form new continents,which then drafted to the present location; the movement of continents | continental drift |
| The process by which Earth's magnetic north pole and magnetic south pole switch positions periodically; a change in the direction in which Earth's magnetic field points | magnetic reversals |
| The theory that Earth's outer layer is made up of large, moving pieces called tonic plates; The theory explain how the plates interact and how those interactions relate to processes such as earthquakes in mountain building | plate tectonics |
| A system of ideas that explains many related observations and is supported by a large body of evidence acquired Scientific investigation. | theory |
| The process by which new oceanic lithosphere ( sea floor) forms when the magma rises to Earth's surface at mid-ocean ridges and solidifies, as older, existing seafloor moves away from the ridge. | sea-floor spreading |
| The process by which one lithospheric plate moves beneath another plate as a result of tectonic forces. | subduction |
| A block of lithosphere that consists of the crust and the rigid, outermost part of the mantle. | tectonic plates |
| The solid outer layer of Earth that consists of the crust and the rigid upper part of the mantle. | lithosphere |
| The soft layer of the mantle on which the tectonic plates move. | asthenosphere |
| a long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading. | mid-ocean ridge |