Yale scientists are claiming to have figure out one of geology ’s great puzzles : Why do tectonic plates sometimes make fleet , dramatic shifts after abyssal eons of microscopic progress ? By “ swift ” geologists mean something that can take up to a million year , rather than the sorting of effect thatwreaks havocon those last near fracture lines . Nevertheless , the study may provide insight to help prognosticate those chemise speedy enough to pose a threat to life and branch .
" Our planet is probably most distinctly marked by the fact that it has denture tectonics , " says Professor David Bercovici , lead writer of the paper published inProceedings of the National Academy of Sciences . " Our work here looks at the evolution of plate tectonics . How and why do plates commute management over time ? "
The standard explanation of plate plate tectonics is that slabs near the Earth ’s Earth’s surface become cold than the spicy inside , and sink , or subduct , into the Earth . As they do so , they drag the surface plate behind them . Rapid alteration in direction occur when slabs unclothe off the plate they are attached to , but geologists have been dumbfound by how this occurs . Cold unbendable slabs should not be detachable , yet in Hawaii and Timor we see evidence of home plate moving at speeds that models ca n’t excuse .
However , Bercovici says that crustal cloth is washed into the subduction zona and this affects the slab ’s behavior . cloth plug away up the zone is enough to start the unconscious process of separating the slab from the photographic plate , and this is accelerated when vast forces take place at such depths shrink mineral cereal , weakening the slab .
Freed from its slab , the tectonic shell may slide sidelong , or in the case of a continent , rise relative to the oceanic plate around it .
Bercovici has been working on explaining plate tectonics for much of his career . Last class alone , he publishednine report related to this subject , admit explanation of why Venus does n’t seem to havedeveloped exchangeable geologyto Earth , despite being so alike in sizing and composition . Bercovici propose that Venus was too red-hot at the open for the formation of dampen slab , preventing the banquet of plate deportment .
When plate movements were first affirm , it was widely assumed that they were drive by effect from below , and that what take place at the surface was irrelevant . However , in recent years , it has become increasingly clear that the whole planet is an interwoven system , and that events at the control surface , include those driven by biota , can have an encroachment on even the mightiest appendage below .
