MAST382 Lecture Notes - Lecture 5: Nazca Plate, Asthenosphere, Outer Core
13 Sep 2016
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Document Summary
Found evidence that plate tectonics was much more than they thought at the time. Seafloor spreading theory seems to explain why the ancestors of a green turtle which now travels 2000 km from brazil to breed at ascension island. Moho is the connection of the upper mantle and oceanic crust or continental crust. Moho depth under ocean is about 10km, pretty consistent throughout all oceans. Bigger depth under land, even bigger under some mountains (mainly andes and. Himalayas ) due to extra weight above the moho. Have never sampled the moho, attempting in the indian ocean. Sedimentary bedrocks-> continental crust -> lithospheric mantle -> asthenosphere -> transition zone-> lower mantle -> outer core -> inner core. Timing and strength of seismic waves gives us a picture of the interior----earthquakes. Average elevate weather continental or oceanic is 2070m. Ancient oceans" is panthalassa ocean and tethys sea during the time of pangea.
