Question | Answer |
Asthenosphere | Plastic like layer of Earth on which the lithospheric plates float and move around. |
Continental Drift | Hypothesis that continents were once connected in a single large land mass that broke apart about 200 mil. years ago. |
Convection Current | Current in Earth's mantle that transfers heat in Earth inteior and is the driving force for plate tectionics. |
Lithosphere | Rigid layer of Earth about 100km thick, made of the crust and part of the upper mantle. |
Pangaea | largte ancient landmass that was composed of all the continents joined together. |
Plate | a large section of Earth's oceanic or continental crust and rigid upper mantle that moves around on the asthenosphere. |
Plate Tectonics | Theory that Earth's crust and upper mantle are broken into plates that float and move around on a plasticlike layer of the mantle. |
Seafloor spreading | Theory that new seafloor is formed when magma is forced upward toward the surface at a mid ocean ridge. |
Who theory was seafloor spreading? | Hess |
Who theory was continental drift? | Wegener |
Subduction Zone | Area where an oceanic plate goes down into the mantle. |
Divergent Boundary | Boundary between two plates that are moving apart. |
Convergent Boundary | Boundary between two plates that are moving together. |
Transform Boundary | Plate boundary that occurs when two plates slide past one another. |
Magneticometer | Sensing device that detects magnetic fields, helping to confirm seafloor spreading. |
Mantle | Largest layer of Earht's surface, composed mostly of silicon, oxygen, magnesium, and iron |
Crust | Outer most layer of Earth's surface. |
Convergent boundarys form | deep sea trenches, volcanic islands, and colcanic mountains. |
Divergent boundarys form | Mid ocean rifts, rift vally |
Transform boundarys form | major earthquakes |