Pourquoi la lithosphère?
La lithosphère est l’enveloppe rigide de la surface de la Terre. Elle comprend la croûte terrestre et une partie du manteau supérieur. Elle est divisée en un certain nombre de plaques tectoniques, également appelées plaques lithosphériques.
Comment est la lithosphère?
La lithosphère représente l’enveloppe solide externe de la Terre. Elle se compose de la croûte (continentale ou océanique) ainsi que de la partie supérieure du manteau. De composition variable, elle se différencie de l’asthénosphère sous-jacente en plusieurs points.
What are the effects of subduction on Earth’s crust?
Metamorphism. Subduction zones host a unique variety of rock types created by the high-pressure,low-temperature conditions a subducting slab encounters during its descent.
Where is subduction most likely to occur?
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.
What are the effects of subduction?
Another side effect of the subduction process is the creation of volcanoes, as well as increased volcanic activity above subduction zones. These subduction zone-created volcanoes occur in one of two formations: island arc or continental arc.
How and why does subduction occur?
Subduction occurs when two plates collide at a convergent boundary , and one plate is driven beneath the other, back into the Earth’s interior. Not all convergence leads to subduction. Continental rocks are too buoyant to be forced downward, so when continents collide, they crumple but stay at the surface.