EARTHSC 1G03 Lecture Notes - Lecture 3: Oceanic Crust, Plate Tectonics, Seafloor Spreading
4 Oct 2016
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Document Summary
With the invention of sonar, regional bathymetry* could now be mapped: * bathymetry: the measurement of depth of water in oceans, seas, or lakes. This was a vital piece to the continental drift puzzle. Mors are: submerged mountain regions usually characterized by the central rift valley. Boiling milk layer on top forms, is eventually ripped apart by new layers. Central rift valleys: the crvs have dropped between huge parallel faults fractures in bedrock along which rocks move relative to one another. Unless the earth is expanding or contracting, the earth must be destroyed somewhere. The pacific ring of fire shows the volcanic and earthquake activity now known to be associated with convergence and destruction of lithospheric plates. All the previous observations are best explained by the seafloor spreading hypothesis, which suggests that oceanic crust: Is created at the mid-ocean ridges: spreads laterally, finally descends back into the mantle at deep-sea trenches.
