Plate data: Bird (2003), PB2002, converted by Hugo Ahlenius, Nordpil (ODC-By 1.0). Land: Natural Earth (India POV).
The Indian Plate carries the Indian subcontinent and part of the Indian Ocean floor. PB2002 maps it separately from the Australian Plate. Older maps often join the two as one Indo-Australian Plate.
Its northern edge is a continent-to-continent collision. USGS explains that when two continents meet head-on, neither sinks, because continental rock is light. The crust buckles and is pushed up instead. India collided with Asia 50 million years ago, and slow convergence since then built the Himalayas and the Tibetan Plateau, most of it in the past 10 million years.
USGS traces India's long trip north. About 225 million years ago, India was a large island off the Australian coast, separated from Asia by a vast ocean called the Tethys Sea. When Pangaea broke apart about 200 million years ago, India began to move north. About 80 million years ago it lay roughly 6,400 km south of Asia, moving north at about 9 m a century, and when it rammed into Asia its advance slowed by about half. The impact has not ended: the Himalayas still rise more than 1 cm a year, and the push of India squeezes parts of Asia eastward toward the Pacific (USGS). On this map Mount Everest sits just north of the boundary, on the Eurasian Plate.1
Bird (2003) keeps India and Australia apart because of the fast and significant motions between them. He lists the India-Australia boundary among those drawn mainly from the pattern of earthquakes, a method he used where new plate boundaries are developing in former plate interiors. In the northwest, the Indian Plate meets the Arabian and Somali Plates at a triple junction whose shape Bird takes from a 2001 study by Fournier and others (Bird 2003).
Indian Plate in numbers
Measured from its PB2002 outline, the Indian Plate covers about 12.4 million km², or 2.4% of the
Earth's surface. That makes it number 10 by area of the 52 plates in the model.
It spans from 7°S to 35°N and from 56°E to 97°E.
Its edge is about 17,119 km long, mostly convergent:
23.1%divergentDivergent boundary. Plates pull away from each other and new crust forms between them. Source (3,957 km)
, 51.5%convergentConvergent boundary. Plates move toward each other and crust is destroyed as one plate dives under another. Source (8,818 km)
and 25.4%transformTransform boundary. Plates slide horizontally past each other. Crust is neither made nor destroyed. Source (4,344 km)
.
Countries whose main landmass sits on this plate: Bangladesh, India, Myanmar, Nepal, Pakistan and Sri Lanka. Countries that straddle a boundary
are listed under the plate that holds the center of their largest landmass.
Along its boundaries it moves a mean 2.8 cm/yr relative to its neighbors, fastest against the Eurasian Plate. Bird (2003)
Neighboring plates Neighbors. Plates that share a boundary with this plate. Most plate movement happens along these narrow zones between plates. Source
The Indian Plate shares a boundary with 5 plates in PB2002, longest shared edge first.
The longest, about 6,038 km, is with the Eurasian Plate; the shortest, about 1,655 km, is with the Arabian Plate.
