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Title: Earlier we discussed the concept of isostasy, where lower density rocks rise higher than higher dens Post by: drelog on Dec 8, 2015 Earlier we discussed the concept of isostasy, where lower density rocks rise higher than higher density rocks. How is the variation of water depth at spreading centers (ridges) controlled by isostasy?
A) Oceanic ridges are sites where the lithosphere is carried into the mantle on one side (aka subduction zones), and the volcanos along these margins produce the ridge by buildup of lower density crust. B) It has nothing to do with isostasy; the areas are simply high because there are chains of active volcanos along the ridge crest, producing the topography. C) The lithosphere cools as it moves away from the ridge axis by sea floor spreading, and cooler rocks are lower density, so the sea floor gets deeper as the lithosphere gets more dense. D) Volcanic rocks are lighter than other rocks, and so the abundant volcanic rocks at the ridges are lower density features that produce the seafloor topography. Title: Re: Earlier we discussed the concept of isostasy, where lower density rocks rise higher than higher Post by: Pulsa on Dec 10, 2015 Content hidden
Title: Re: Earlier we discussed the concept of isostasy, where lower density rocks rise higher than higher dens Post by: drelog on Dec 15, 2015 Double checked your answer with my friend, it's right :D
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