Thick layers of sediment may accumulate in the trench, and these and the subducting plate rocks contain water that subduction transports to depth, which at higher temperatures and pressures enables melting to occur and ‘magmas’ to form. The hot buoyant magma rises up to the surface, forming chains of volcanoes.Read More →
Subduction zones are where the cold oceanic lithosphere sinks back into the mantle and is recycled. They are found at convergent plate boundaries, where the oceanic lithosphere of one plate converges with the less dense lithosphere of another plate. Does subduction occur at all boundaries? Subduction occurs when two platesRead More →
Most earthquakes occur at the boundaries where the plates meet. … Earthquakes at transform faults tend to occur at shallow depths and form fairly straight linear patterns. Subduction zones are found where one plate overrides, or subducts, another, pushing it downward into the mantle where it melts. Why do deepRead More →
Subduction zones occur all around the edge of the Pacific Ocean, offshore of Washington, Canada, Alaska, Russia, Japan and Indonesia. Called the “Ring of Fire,” these subduction zones are responsible for the world’s biggest earthquakes, the most terrible tsunamis and some of the worst volcanic eruptions. Why do subduction zonesRead More →
It is simply not scientifically feasible to predict, or even estimate, when the next Cascadia earthquake will occur, but the calculated odds that a Cascadia earthquake will occur in the next 50 years range from 7-15 percent for a great earthquake affecting the entire Pacific Northwest to about 37 percentRead More →
As the plate sinks it heats up and dehydrates, water is released from minerals and cracks in the sinking plate. This water is hotter than the surrounding rocks and rises up into the mantle. The addition of these hot fluids lowers the pressure and causes the mantle rocks to melt.Read More →
Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth’s interior. … When an oceanic plate collides with a continental plate, the denser oceanic plate is bent downward and slides under the edge of the continent. What areRead More →
These subduction zones can create deep trenches. As the denser plate edge moves downward, the pressure and temperature surrounding it increases, which causes changes to the plate that melt the mantle above, and the melted rock rises through the plate, sometimes reaching its surface as part of a volcano. WhyRead More →