Convergent Margin—Subduction to Tsunami (Educational) скачать в хорошем качестве

Convergent Margin—Subduction to Tsunami (Educational)

www.iris.edu/earthquake for more animations. In this animation, we are showing an ocean/continent convergent boundary. We see the denser thinner oceanic plate diving beneath the continental plate. The down-going oceanic plate eventually melts and gets absorbed into the mantle. Such destruction (recycling) of crust takes place along convergent boundaries where plates collide and a plate is subducted. (This animation does not address volcanoes formed inboard of the boundary where water released from the oceanic plate facilities magma production in the mantle wedge beneath the continent.) More info at: http://www.iris.edu/hq/programs/educa... Uploader Comments ( IRISEnO ) This animation doesn't show magma formation, which would be at depth off the right of the animation. Magma (melted rock under ground) forms when water "sweats" off the subducting plate and rises into the mantle rock of the overlying continental plate. The water lowers the melting temperature of the rock and small bits of melt rise. When it rises to the surface, it can erupt as lava. If the magma holds lots of gas, it can erupt explosively when it reaches the surface where pressures are lower. Animation by Jenda Johnson, Earth Sciences Animated Narrated by Roger Groom, Mount Tabor Middle School, Portland OR