110 likes | 363 Views
volcanism. Types of volcanoes. Underwater Volcanism!. The formation of underwater volcanoes is very similar to the ones on dry land. The pressure of the magma builds up and when it finds a weak spot on the crust it rips it open and starts an eruption .
E N D
volcanism Types of volcanoes
Underwater Volcanism! • The formation of underwater volcanoes is very similar to the ones on dry land. The pressure of the magma builds up and when it finds a weak spot on the crust it rips it open and starts an eruption. • Over time, underwater volcanoes will grow in size and may eventually become islands.
Most underwater volcanoes are found at mid ocean ridges and erupt basaltic lava in a form called pillow basalts. The volcanoes at mid ocean ridges contribute to sea floor spreading. • Volcanoes that develop underwater at hot spots or sub-duction zones are likely to build up into island.
Volcanism at Destructive Plate Boundary • Volcanoes are caused by the dense oceanic plate being sub ducted under the lighter continental plate, this causes immense pressure as the oceanic crust enters the mantle it melts, this magma is forced to create a chamber creating rock as it cools, this results in a volcano being formed. • Volcanoes have to erupt occasionally to disperse the pressure that is built up by the oceanic plate going under and melting under the continental plate.
Underwater volcanism Volcanism at destructive plate boundary
Volcanism At Hotspot • A hot spot is a very hot region deep within the Earth. It is usually responsible for volcanic activity. Volcanic activity happens whenever red-hot material from the Earths thickest layer, the mantle, rises up and leaks through to the Earths surface, the crust. The red-hot material, called magma, sometimes erupts in the form of lava. Lava is the red-orange substance that spills out of a volcano onto the surface. • The magma heats up groundwater under the Earths surface, which causes water and steam to erupt like a volcano.
There are 40 to 50 hot spots around the world, including near the Galapagos Islands and Iceland. Scientists use hot spots to track the movement of the Earths plates. The Pacific plate is just one of many tectonic plates that make up the Earth.
WE HOPE YOU ENJOYED IT!
MADE BY:- MARYAM SHAHID, MISHAL FATIMA & ANSHARAH IMRAN VIII-E