Indian Plate

The Indian plate is a medium sized continental plate. Along with some large, several medium and many small continental plates to add these plates together according to the theory of plate tectonics, the Earth's crust. The one part of the Indian tectonic plate consists of oceanic crust, the northern part of the Indian Ocean, and the other part of continental crust, the Indian subcontinent. To some extent, the Indian plate with the Australian plate which carries the entire Australian continent, the island of New Guinea, a part of New Zealand and the eastern Indian Ocean and part of the Pacific, summarized the Indo -Australian plate.

Geographical location

The Indian plate is bordered to the north in the Himalayas and the Hindu Kush and in the east in Burma to the Eurasian plate, where the Sunda Trench is the small Burma plate between Eurasian and Indian plate, in the south- east on the Australian Plate, in the south- west the African plate and on the west by the Arabian plate.

The on the firm to tough -plastic mantle " floating " lithospheric plate moves with an average of about 5.4 cm in the northeast, where the local velocity can vary by several centimeters per year.

Plate edge

The Indian plate is in the Indian Ocean from a divergent plate boundary ( divergently ) surrounded, facing the African plate which is the northern part of the Central Indian Ridge, which is also known as the Northwest Indian back or Carlsberg back.

A convergent plate boundary ( crashing ) is the northern Sunda Trench in the eastern Indian Ocean, caused by the subduction of the Indo -Australian lithospheric plate and leaves the northern Sunda arc, a 6,000- kilometer long island arc can occur. Another convergent plate boundary is located in the northern part of the Indian plate. Here it comes into collision with the Eurasian land mass, whereby the Himalayas and the Tibetan Plateau unfolds.

Between the Indian and the Australian plate is available in large sections no clear demarcation so that the Indian plate is sometimes grouped with the Australian plate to the Indo -Australian plate. However, some scientists believe that since a few million years, the two plates begin to separate from each other.

A conservative plate boundary ( sliding past each other ) is located opposite the Arabian plate, called the Owen Fracture Zone.

Plate surface

In the Indian Ocean, is the 4000 km long undersea mountains of the Ninety- East or East Indian Ridge, which was generated by a plume. The Chagos - Laccadive ridge is also caused by hot-spot volcanism. It extends in places up to the sea surface, which he built the atolls and coral reefs of the Maldives, the Chagos Archipelago, the island groups of Lakshadweep and amine divas and the island of Minicoy.

Geological History

Before 130-125 million years ago, a continent, which at the time of the Indian subcontinent, today's island of Madagascar and the islands of the Seychelles were, from Antarctica and Australia, which were part of the supercontinent Gondwana at that time. Separated 90 million years ago also Madagascar separated from the Indian plate, while the remaining part began with the geological high speed of up to 20 cm / year to migrate northward. The cause of this extraordinary speeds is believed by some scientists that the lithosphere of the Indian plate at 100 km is only about half as thick as the lithosphere of the other fragments of Gondwana. About 65 million years separated the islands of the Seychelles of the Indian plate, the new interface is now called Carlsberg back.

Before about 65 million years ago the Indian plate ran over a hot spot. Witnesses of this event are the Deccan Traps in what is now western India. This in some places more than 2000 m thick layer of basalt, which forms the Indian landscape of the Deccan, it now covers an area of ​​more than 500,000 square kilometers. The hot spot caused by the passage of the Indian subcontinent, then the formation of the Chagos - Laccadive Ridge and is now the territory of the volcanic island of Réunion, below the African plate.

40 million years ago the collision of the Indian subcontinent with Asia began. Since then, the continental crust of the Indian plate is pushed beneath the Eurasian plate ( thrust ). Furthermore, the Eurasian plate is thickened, so that the crust beneath the Himalayas and the highlands of Tibet today reached a thickness of 60 km. The global average of the thickness of the crust is 35 km. The subcontinent today still comes with 5 cm or more in the year to the northeast into Asia, with the rising mountains is simultaneously eroded and shaped by erosion. The average altitude of the Himalayas and the highlands of Tibet is slightly less than 5 km. , Although individual project in the Himalayas mountains far above the average height also. Over the past million years, large amounts of rock were shipped from the mountains. Calculations show that have accumulated about 8.5 million cubic kilometers of rock in front of the Himalayas and the Ganges delta.

Earthquake

Progress of the Indian plate and Eurasian plate produces stresses in the earth's crust, which not only leads to unfolding of the Himalayas, the uplift of the Tibetan Plateau and the evasion of crustal material to the east, but also cause numerous strong earthquakes.

In 1934 an earthquake in the Kathmandu Valley, Nepal had a magnitude of 8.3 on the Richter scale.

In December 2004, there were in the area between the Indian, the Australian and the Burma plate to the Indian Ocean Tsunami of 2004. The earthquake in Burma - plate had a magnitude of about 9.0 on the Richter scale with hypocenter off the north west coast Sumatra (3 ° 19 ' N, 95 ° 51' O3.31695.854 ). It caused by several tsunamis devastating damage in coastal regions in the Bay of Bengal, the Andaman Sea, in large parts of South Asia and also on the coast of East Africa. It is estimated that the quake urged some 230,000 lives.

The cause of the earthquake of December 2004 was a sudden shift in the earth's crust. Thus, the Simeulue Island closest to the epicenter was shifted about 15 meters in southwestern direction. Another consequence is the sinking of 15 smaller of the 572 islands of the Andaman and Nicobar Islands below sea level.

With the earthquake off Sumatra in 2005 a large aftershocks in the region ( 2 ° 5 ' N, 97 ° 1' O2.076388888888997.016111111111 ), which had a magnitude of 8.7 on the Richter Scale, occurred in March 2005, in addition to many smaller aftershocks, and about 1300 human lives.

On 8 October 2005, the Kashmir earthquake occurred near Muzaffarabad (34 ° 26 ' N, 73 ° 32' O34.43194444444473.536944444444 ). Almost 85,000 people came primarily in Pakistan but also in India killed and many villages were destroyed.

Even the severe earthquake in Sichuan in 2008 went back to the advance of the Indian plate and Eurasian. The compressed between the rigid interior of the Eurasian and Indian plate rocks of the Tibetan Plateau and its surrounding soft to the east and run over while the Sichuan Basin. Also the recurrence of major earthquakes on the fault zones existing there.

Research

In 2011 it was announced that in the area of the highlands of Tibet should be a microplate, the so-called Tibetan plate. Both the Eurasian plate and the Indian plate to be pushed under the newly discovered Tibetan plate, which moves at five centimeters per year to the northeast.