Just as oceanic crust is formed at mid-ocean ridges, it is destroyedin subduction zones. Subduction is the important geologic process in which a tectonic plate made of dense lithospheric material melts or falls below a plate made of less-dense lithosphere at a convergent plate boundary. Why doe...
文档标题《Shield volcanoes, built almost entirely of lava flows, occur at mid-ocean ridges and hot spots[盾状火山,内置的熔岩流几乎完全,发生在大洋中脊和热点]》,总页数为37页,主要介绍了与Shield volcanoes, built almost entirely of lava flows, occur at mid-ocean ridges and hot spots[盾状火山,...
Earthquakes most often occur near the edges of tectonic plates. These enormous slabs of crustal rock — as large as countries or even entire continents — underlie all of the Earth's surface, extending some 70 kilometers (43 miles) deep. Tectonic plates may hold landmasses, water bodies or ...
SO2 and CO2 released by these submerged volcanos have two dramatic effects: convection currents and acidification of the ocean (something blamed on AGW but actually volcanic in origin). Recent tectonic activity has been observed under antarctica recorded as earthquakes along the transantarctic mountains...
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Mostearthquakesandvolcanoesoccuralongplateboundaries Newoceancrustiscreatedalongmid-oceanridges Oldoceancrustisrecycledatsubductionzones Subductionzonesarewheremountain-building(orogeny)occurs Smallpiecesofcrust(terranes)areimportantinbuildingupcontinents Hotspotsarelonglivedstationarymagmasources ...
volcanoesandepicentersofearthquakes.Someoftheboundaries,suchasthemid- Atlanticridge,areidentifiedasspreadingridges,wherebirthisgiventonewcrustal material;otherboundaries,suchasthetrenchofthewestcoastofSouthAmerica,are identifiedassubductionzoneswhereoldcrustisbeingpulledorpushedbackintothe ...
90% at plate boundaries -found at all 3 types of boundaries location of shallow earthquakes along oceanic ridge system, lack of deep focus earthquakes at ridge. Note distribution by trenches: Shallow focus earthquakes occur within or adjacent to trenches, while intermediate and deeper occur towards...
themagmaeruptsontothesurface.Strong earthquakesaccompanyrisingmagma,andthe volcanicconemayswellinappearance,justbefore aneruption,asillustratedinthispicture.White arrowsinthepictureshowthevolcanogetting biggerasmagmarisesinside.Scientistoften monitorthechangingshapeofavolcano, especiallypriortoaneruption.Thedifferent ...