Where oceanic and continental plates collide, the denser oceanic plate (2.9
grams per cubic centimetre) is subducted under the light continental plate
(2.7 grams per cubic centimetre). Where the oceanic plate is forced below the
continental plate a trench is formed e.g. the Peru-Chile trench.
The oceanic plate is moving into the asthenosphere, due to this the pressure builds which results in major earthquakes. For example, the 2010 Chile earthquake was the 6th largest earthquake recorded by a seismograph. It had a magnitude of 8.8 and 525 people died and it also triggered a Tsunami and 53 countries where warned. Moreover, as the plate descends further the oceanic plate beings to melts due to a huge amount of friction, it begins to melt in the Benioff Zone. The crust becomes molten, which is called magma, and this is less dense than the asthenosphere and it begins to rise. This eventually makes volcanoes. The lava is andesitic which is viscous and creates composite, explosive volcanoes.
Finally, With the Nazca plate moving a 12 cm per year and the south American plate moving at 1 cm per year, the continental plate beings to crumple and form fold mountains. this along with the volcanoes form the Andes mountain range along the western coast of South America.
grams per cubic centimetre) is subducted under the light continental plate
(2.7 grams per cubic centimetre). Where the oceanic plate is forced below the
continental plate a trench is formed e.g. the Peru-Chile trench.
The oceanic plate is moving into the asthenosphere, due to this the pressure builds which results in major earthquakes. For example, the 2010 Chile earthquake was the 6th largest earthquake recorded by a seismograph. It had a magnitude of 8.8 and 525 people died and it also triggered a Tsunami and 53 countries where warned. Moreover, as the plate descends further the oceanic plate beings to melts due to a huge amount of friction, it begins to melt in the Benioff Zone. The crust becomes molten, which is called magma, and this is less dense than the asthenosphere and it begins to rise. This eventually makes volcanoes. The lava is andesitic which is viscous and creates composite, explosive volcanoes.
Finally, With the Nazca plate moving a 12 cm per year and the south American plate moving at 1 cm per year, the continental plate beings to crumple and form fold mountains. this along with the volcanoes form the Andes mountain range along the western coast of South America.