Describe the formation of hotspots and explain their relationship to plate movement. | MyTutor
Plate tectonics has been on the curriculum for a while now. molten rock push against continental plates and drive their movement. Around The Great Rift Valley in eastern Africa, shown in the photograph above, is a good example of a continental rift valley. It is getting wider as the African Plate splits. Mantle plumes are areas of hot, upwelling mantle. A hot spot develops above the plume. Magma generated by the hot spot rises through the rigid plates of the.
Mantle plumes appear to be largely unaffected by plate motions.
While a plume that feeds hot spot volcanoes remains stationary relative to the mantle, the plate above it usually moves. The result is that a chain of progressively older volcanoes are created on the overlying plate. The best examples of such "hot spot tracks" are found in the Pacific Ocean.
The Pacific plate contains several linear belts of extinct submarine volcanoes, called seamounts. The formation of at least some of these intraplate seamount chains can be attributed to volcanism above a mantle hotspot to form a linear, age-progressive hotspot track.
Intraplate (hot-spot) volcanism
As the Pacific plate move across stationary hotspots, volcanism will generate volcanoes either as active submarine seamounts or volcanic islands that only are active as long as they are above the mantle plume. As the plate moves them away from their source, their magma supply is eventually cut off and they become extinct, while new volcanoes are formed above the hot spot. Thus, a linear chain of seamounts and island volcanoes is formed.
When an individual volcano has moved away from the source, erosion and sinking caused by its own weight take over and most islands become seamounts again with time. On a smaller timescale, plate tectonics is responsible for earthquakes, volcanoes and tidal waves.
Now, scientists at the Scripps Institution of Oceanography have identified a new force driving plate tectonics: Published in the journal Naturethe research shows that these hotspots, or "mantle plumes", are responsible for the movement of whole continents.Hawaii's Hotspot
These plumes of incredibly hot, molten rock push against continental plates and drive their movement. Around 70 million years ago, the tectonic plate that now includes the Indian subcontinent lay northeast of Madagascar. Suddenly, it started moving incredibly quickly - by geological standards - at 10 centimetres per year. Around the same time, a spate of huge volcanoes occurred at the Deccan Plateau, sited in the area that is now India.
How are hot spots related to plate tectonics? + Example
Molten lava was thrown over around 1. Steve Cande and Dave Stegman, who led the study for Scripps Institution of Oceanography, tracked movements of continental plates throughout Earth's history. Their research suggests that the Indian subcontinent tectonic plate sat over a powerful mantle plume which began around 70 million years ago, around what is now the Reunion Islands. This rising mass of hot rock hit the Earth's crust and spread out.
The pushing force of the mantle plume sent the Indian plate hurtling towards what is now Asia.