Indian Plate

The Indian Plate or India Plate is a major tectonic plate straddling the equator in the eastern hemisphere. Originally a part of the ancient continent of Gondwana, India broke away from the other fragments of Gondwana 100 million years ago and began moving north.[2] Once fused with the adjacent Australia to form a single Indo-Australian Plate, recent studies suggest that India and Australia have been separate plates for at least 3 million years and likely longer.[3] The Indian Plate includes most of South Asia—i.e. the Indian subcontinent—and a portion of the basin under the Indian Ocean, including parts of South China and western Indonesia,[4][5] and extending up to but not including Ladakh, Kohistan and Balochistan.[6][7][8]

Indian Plate
The Indian Plate
TypeMajor
Coordinates34°25′55″N 73°32′13″E / 34.43194°N 73.53694°ECoordinates: 34°25′55″N 73°32′13″E / 34.43194°N 73.53694°E
Approximate area11,900,000 km2 (4,600,000 sq mi)[1]
Movement1north-east
Speed126–36 millimetres per year (1.0–1.4 in/year)
FeaturesIndian Ocean, Himalayas
1Relative to the African Plate

Plate movements

Himalaya-formation
Due to plate tectonics, the India Plate split from Madagascar and collided (c. 55 Mya) with the Eurasian Plate, resulting in the formation of the Himalayas.

Until roughly 140 million years ago, the Indian Plate formed part of the supercontinent Gondwana together with modern Africa, Australia, Antarctica, and South America. Gondwana broke up as these continents drifted apart at different velocities,[9] a process which led to the opening of the Indian Ocean.[10]

In the late Cretaceous, approximately 100 million years ago and subsequent to the splitting off from Gondwana of conjoined Madagascar and India, the Indian Plate split from Madagascar. It began moving north, at about 20 centimetres (7.9 in) per year,[9] and is believed to have begun colliding with Asia as early as 55 million years ago,[11] in the Eocene epoch of the Cenozoic. However, some authors suggest that the collision between India and Eurasia occurred much later, around 35 million years ago.[12] If the collision occurred between 55 and 50 Mya, the Indian Plate would have covered a distance of 3,000 to 2,000 kilometres (1,900–1,200 mi), moving faster than any other known plate. In 2012, paleomagnetic data from the Greater Himalaya was used to propose two collisions to reconcile the discrepancy between the amount of crustal shortening in the Himalaya (~1,300 kilometres or 800 miles) and the amount of convergence between India and Asia (~3,600 kilometres or 2,200 miles).[13] These authors propose a continental fragment of northern Gondwana rifted from India, traveled northward, and initiated the "soft collision" between the Greater Himalaya and Asia at ~50 Mya. This was followed by the "hard collision" between India and Asia occurred at ~25 Mya. Subduction of the resulting ocean basin that formed between the Greater Himalayan fragment and India explains the apparent discrepancy between the crustal shortening estimates in the Himalaya and paleomagnetic data from India and Asia. However, the proposed ocean basin was not constrained by paleomagnetic data from the key time interval of ~120 Mya to ~60 Mya. New paleomagnetic results of this critical time interval from southern Tibet do not support this Greater Indian Ocean basin hypothesis and the associated dual collision model.[14]

In 2007, German geologists[9] suggested that the reason the Indian Plate moved so quickly is that it is only half as thick (100 kilometres or 62 miles) as the other plates[15] which formerly constituted Gondwana. The mantle plume that once broke up Gondwana might also have melted the lower part of the Indian subcontinent, which allowed it to move both faster and further than the other parts.[9] The remains of this plume today form the Marion Hotspot (Prince Edward Islands), the Kerguelen hotspot, and the Réunion hotspots.[10][16] As India moved north, it is possible that the thickness of the Indian Plate degenerated further as it passed over the hotspots and magmatic extrusions associated with the Deccan and Rajmahal Traps.[10] The massive amounts of volcanic gases released during the passage of the Indian Plate over the hotspots have been theorised to have played a role in the Cretaceous–Paleogene extinction event, generally held to be due to a large asteroid impact.[17]

The collision with the Eurasian Plate along the boundary between India and Nepal formed the orogenic belt that created the Tibetan Plateau and the Himalaya Mountains, as sediment bunched up like earth before a plow.

The Indian Plate is currently moving north-east at five centimetres (2.0 in) per year, while the Eurasian Plate is moving north at only two centimetres (0.79 in) per year. This is causing the Eurasian Plate to deform, and the Indian Plate to compress at a rate of four millimetres (0.16 in) per year.

Geography

The westerly side of the Indian Plate is a transform boundary with the Arabian Plate called the Owen Fracture Zone, and a divergent boundary with the African Plate called the Central Indian Ridge (CIR). The northerly side of the Plate is a convergent boundary with the Eurasian Plate forming the Himalaya and Hindu Kush mountains.

See also

Notes

  1. ^ "Sizes of Tectonic or Lithospheric Plates". Geology.about.com. 2014-03-05. Retrieved 2016-01-13.
  2. ^ Oskin, Becky (2013-07-05). "New Look at Gondwana's Breakup". Livescience.com. Retrieved 2016-01-13.
  3. ^ Stein, Seth; Sella, Giovanni F.; Okai, Emile A. (2002). "The January 26, 2001 Bhuj Earthquake and the Diffuse Western Boundary of the Indian Plate" (PDF). Geodynamics Series. American Geophysical Union: 243–254. doi:10.1029/GD030p0243. ISBN 9781118670446. Retrieved 2015-12-25.
  4. ^ Sinvhal, Understanding Earthquake Disasters, p. 52, Tata McGraw-Hill Education, 2010, ISBN 978-0-07-014456-9
  5. ^ Harsh K. Gupta, Disaster management, p. 85, Universities Press, 2003, ISBN 978-81-7371-456-6
  6. ^ M. Asif Khan, Tectonics of the Nanga Parbat syntaxis and the Western Himalaya, p. 375, Geological Society of London, 2000, ISBN 978-1-86239-061-4
  7. ^ Srikrishna Prapnnachari, Concepts in Frame Design, page 152, Srikrishna Prapnnachari, ISBN 978-99929-52-21-4
  8. ^ A. M. Celâl Şengör, Tectonic evolution of the Tethyan Region, Springer, 1989, ISBN 978-0-7923-0067-0
  9. ^ a b c d Kind 2007
  10. ^ a b c Kumar et al. 2007
  11. ^ Scotese 2001
  12. ^ Aitchison, Ali & Davis 2007
  13. ^ van Hinsbergen, D.; Lippert, P.; Dupont-Nivet, G.; McQuarrie, N.; Doubrivine, P.; Spakman, W.; Torsvik, T. (2012). "Greater India Basin hypothesis and a two-stage Cenozoic collision between India and Asia". Proceedings of the National Academy of Sciences. 109 (20): 7659–7664. Bibcode:2012PNAS..109.7659V. doi:10.1073/pnas.1117262109. PMC 3356651. PMID 22547792.
  14. ^ Qin, Shi-Xin; Li, Yong-Xiang; Li, Xiang-Hui; Xu, Bo; Luo, Hui (2019-01-17). "Paleomagnetic results of Cretaceous cherts from Zhongba, southern Tibet: New constraints on the India-Asia collision". Journal of Asian Earth Sciences. 173: 42–53. doi:10.1016/j.jseaes.2019.01.012. ISSN 1367-9120.
  15. ^ The lithospheric roots in South Africa, Australia, and Antarctica are 300 to 180 kilometres (190 to 110 mi) thick. (Kumar et al. 2007) See also Kumar et al. 2007, figure 1
  16. ^ Meert, J.G.; Tamrat, Endale (2006). "Paleomagnetic evidence for a stationary Marion hotspot: Additional paleomagnetic data from Madagascar". Gondwana Research. 10 (3–4): 340–348. Bibcode:2006GondR..10..340M. doi:10.1016/j.gr.2006.04.008.
  17. ^ Schulte, Peter; et al. (5 March 2010). "The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary" (PDF). Science. AAAS. 327 (5970): 1214–1218. Bibcode:2010Sci...327.1214S. doi:10.1126/science.1177265. ISSN 1095-9203. PMID 20203042.

References

External links

2014 Yingjiang earthquake

The 2014 Yingjiang earthquake occurred on 24 May at 4:49 a.m. local time in Yingjiang County, Yunnan Province, China, with a moment magnitude of 5.6 and a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. The epicenter was in the town of Kachang. There were 14 aftershocks, according to the Yunnan provincial seismological bureau.The earthquake affected about 23,800 people and destroyed 9,412 homes. More than 8,000 people were evacuated and a power outage occurred around the epicenter. The Yunnan region is seismically active, lying within the complex zone of deformation caused by the ongoing collision between the Eurasian Plate and Indian Plate.

Alpine orogeny

The Alpine orogeny or Alpide orogeny is an orogenic phase in the Late Mesozoic (Eoalpine) and the current Cenozoic that has formed the mountain ranges of the Alpide belt. These mountains include (from west to east) the Atlas, the Rif, the Baetic Cordillera, the Cantabrian Mountains, the Pyrenees, the Alps, the Apennine Mountains, the Dinaric Alps, the Pindus (Hellenides), the Carpathians, the Balkanides - Balkan Mountains and Rila-Rhodope massifs, the Pontic Mountains, the Taurus, the Armenian Highlands, the Caucasus, the Alborz, the Zagros, the Hindu Kush, the Pamir, the Karakoram, and the Himalayas. Sometimes other names occur to describe the formation of separate mountain ranges: for example Carpathian orogeny for the Carpathians, Hellenic orogeny for the Pindus, Altai orogeny for Altai Mountains or the Himalayan orogeny for the Himalayas.

The Alpine orogeny has also led to the formation of more distant and smaller geological features such as the Weald–Artois Anticline in southern England and northern France, the remains of which can be seen in the chalk ridges of the North and South Downs in southern England. Its effects are particularly visible on the Isle of Wight, where the Chalk Group and overlying Eocene strata are folded to near-vertical, as seen in exposures at Alum Bay and Whitecliff Bay, and on the Dorset coast near Lulworth Cove. Stresses arising from the Alpine orogeny caused the Cenozoic uplift of the Sudetes mountain range and possibly faulted rocks as far away as Öland in southern Sweden during the Paleocene.The Alpine orogeny is caused by the continents Africa and India and the small Cimmerian plate colliding (from the south) with Eurasia in the north. Convergent movements between the tectonic plates (the Indian plate and the African plate from the south, the Eurasian plate from the north, and many smaller plates and microplates) had already begun in the early Cretaceous, but the major phases of mountain building began in the Paleocene to Eocene. The process continues currently in some of the Alpide mountain ranges.

The Alpine orogeny is considered one of the three major phases of orogeny in Europe that define the geology of that continent, along with the Caledonian orogeny that formed the Old Red Sandstone Continent when the continents Baltica and Laurentia collided in the early Paleozoic, and the Hercynian or Variscan orogeny that formed Pangaea when Gondwana and the Old Red Sandstone Continent collided in the middle to late Paleozoic.

Australian Plate

The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately 100 million years ago when India broke away and began moving north. Australia and Antarctica began rifting 85 million years ago and completely separated roughly 45 million years ago. The Australian plate later fused with the adjacent Indian Plate beneath the Indian Ocean to form a single Indo-Australian Plate. However, recent studies suggest that the two plates have once again split apart and have been separate plates for at least 3 million years and likely longer. The Australian Plate includes the continent of Australia, including Tasmania, as well portions of New Guinea, New Zealand, and the Indian Ocean basin.

Bengal Fan

The Bengal Fan, also known as the Ganges Fan, is the largest submarine fan on Earth. The fan is about 3,000 km (1,900 mi) long, 1,430 km (890 mi) wide with a maximum thickness of 16.5 km (10.3 mi). The fan resulted from the uplift and erosion of the Himalayas and the Tibetan Plateau produced by the collision between the Indian Plate and the Eurasian Plate. Most of the sediment is supplied by the Ganges and Brahmaputra rivers which supply the Lower Meghna delta in Bangladesh and the Hoogly delta in West Bengal (India). Several other large rivers in Bangladesh and India provide smaller contributions. Turbidity currents have transported the sediment through a series of submarine canyons, some of which are more than 1,500 miles (2,414 km) in length, to be deposited in the Bay of Bengal up to 30 degrees latitude from where it began. To date, the oldest sediments recovered from the Bengal fan are from Early Miocene age. Their mineralogical and geochemical characteristics allow to identify their Himalayan origin and demonstrate that the Himalaya was already a major mountain range 20 million years ago.The fan completely covers the floor of the Bay of Bengal. It is bordered to the west by the continental slope of eastern India, to the north by the continental slope of Bangladesh and to east by the northern part of Sunda Trench off Myanmar and the Andaman Islands, the accretionary wedge associated with subduction of the Indo-Australian Plate beneath the Sunda Plate and continues along the west side of the Ninety East Ridge. The Nicobar Fan, another lobe of the fan, lies east of the Ninety East Ridge.The fan is now being explored as a possible source of fossil fuels for the surrounding developing nations.

The fan was first identified by bathymetric survey in the sixties by Bruce C. Heezen and Marie Tharp which identified the abyssal cone and canyon structures. It was delineated and named by Joseph Curray and David Moore following a geological and geophysical survey in 1968.A deep sea canyon called Swatch of no Ground is located south of Sundarbans National Park and the island of Dublar Char. This area hosts important habitats for cetaceans including endangered species such as various dolphins, Irrawaddy dolphins, and Bryde's whales (see Sundarbans National Park).

Capricorn Plate

The Capricorn Plate is a proposed minor tectonic plate lying beneath the Indian Ocean basin in the southern and eastern hemispheres. The original theory of plate tectonics as accepted by the scientific community in the 1960s assumed fully rigid plates and relatively narrow, distinct plate boundaries. However, research in the late 20th and early 21st centuries suggests that certain plate junctions are diffuse across several dozen or even hundred kilometres. The Capricorn Plate is a relatively rigid piece of oceanic crust along the far western edge of the former Indo-Australian Plate. The Capricorn Plate was once joined with the Indian Plate and the Australian Plate to form the Indo-Australian Plate, but recent studies suggest that the Capricorn Plate began separating from the Indian and Australian Plates between 18 million years ago and 8 million years ago along a wide, diffuse boundary.

Earthquake zones of India

The Indian subcontinent has a history of devastating earthquakes. The major reason for the high frequency and intensity of the earthquakes is that the Indian plate is driving into Asia at a rate of approximately 47 mm/year. Geographical statistics of India show that almost 54% of the land is vulnerable to earthquakes. A World Bank and United Nations report shows estimates that around 200 million city dwellers in India will be exposed to storms and earthquakes by 2050. The latest version of seismic zoning map of India given in the earthquake resistant design code of India [IS 1893 (Part 1) 2002] assigns four levels of seismicity for India in terms of zone factors. In other words, the earthquake zoning map of India divides India into 4 seismic zones (Zone 2, 3, 4 and 5) unlike its previous version, which consisted of five or six zones for the country. According to the present zoning map, Zone 5 expects the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity.

Geography of India

India lies on the Indian Plate, the northern portion of the Indo-Australian Plate, whose continental crust forms the Indian subcontinent. The country is situated north of the equator between 8°04' to 37°06' north latitude and 68°07' to 97°25' east longitude. It is the seventh-largest country in the world, with a total area of 3,287,263 square kilometres (1,269,219 sq mi). India measures 3,214 km (1,997 mi) from north to south and 2,933 km (1,822 mi) from east to west. It has a land frontier of 15,200 km (9,445 mi) and a coastline of 7,516.6 km (4,671 mi).On the south, India projects into and is bounded by the Indian Ocean—in particular, by the Arabian Sea on the west, the Lakshadweep Sea to the southwest, the Bay of Bengal on the east, and the Indian Ocean proper to the south. The Palk Strait and Gulf of Mannar separate India from Sri Lanka to its immediate southeast, and the Maldives are some 125 kilometres (78 mi) to the south of India's Lakshadweep Islands across the Eight Degree Channel. India's Andaman and Nicobar Islands, some 1,200 kilometres (750 mi) southeast of the mainland, share maritime borders with Myanmar, Thailand and Indonesia. Kanyakumari at 8°4′41″N and 77°55′230″E is the southernmost tip of the Indian mainland, while the southernmost point in India is Indira Point on Great Nicobar Island. The northernmost point which is under Indian administration is Indira Col, Siachen Glacier. India's territorial waters extend into the sea to a distance of 12 nautical miles (13.8 mi; 22.2 km) from the coast baseline. India has the 18th largest Exclusive Economic Zone of 2,305,143 km2 (890,021 sq mi).

The northern frontiers of India are defined largely by the Himalayan mountain range, where the country borders China, Bhutan, and Nepal. Its western border with Pakistan lies in the Karakoram range, Punjab Plains, the Thar Desert and the Rann of Kutch salt marshes. In the far northeast, the Chin Hills and Kachin Hills, deeply forested mountainous regions, separate India from Burma. On the east, its border with Bangladesh is largely defined by the Khasi Hills and Mizo Hills, and the watershed region of the Indo-Gangetic Plain.The Ganga is the longest river originating in India. The Ganga–Brahmaputra system occupies most of northern, central, and eastern India, while the Deccan Plateau occupies most of southern India. Kangchenjunga, in the Indian state of Sikkim, is the highest point in India at 8,586 m (28,169 ft) and the world's third highest peak. Climate across India ranges from equatorial in the far south, to alpine and tundra in the upper reaches of the Himalayas. the geographic view of India is pretty expository and vivid in the terms of area, mountains and relief.

Geography of Pakistan

The Geography of Pakistan (Urdu: جغرافیۂ پاکِستان‎) is a profound blend of landscapes varying from plains to deserts, forests, hills, and plateaus ranging from the coastal areas of the Arabian Sea in the south to the mountains of the Karakoram range in the north. Pakistan geologically overlaps both with the Indian and the Eurasian tectonic plates where its Sindh and Punjab provinces lie on the north-western corner of the Indian plate while Balochistan and most of the Khyber Pakhtunkhwa lie within the Eurasian plate which mainly comprises the Iranian Plateau. Gilgit-Baltistan and Azad Kashmir lie along the edge of the Indian plate and hence are prone to violent earthquakes where the two tectonic plates collide.

Pakistan is bordered by India to the east, Afghanistan to the northwest and Iran to the west while China borders the country in the northeast. The nation is geopolitically placed within some of the most controversial regional boundaries which share disputes and have many-a-times escalated military tensions between the nations, e.g., that of Kashmir with India and the Durand Line with Afghanistan. Its western borders include the Khyber Pass and Bolan Pass that have served as traditional migration routes between Central Eurasia and South Asia.

At 796,096 square kilometres (307,374 sq mi), Pakistan is the 36th largest country by area, more than twice the size of the US state of Montana, and slightly larger than the Canadian province of Alberta.

Geology of India

The geology of India is diverse. Different regions of India contain rocks belonging to different geologic periods, dating as far back as the Eoarchean Era. Some of the rocks are very deformed and altered. Other deposits include recently deposited alluvium that has yet to undergo diagenesis. Mineral deposits of great variety are found in the Indian subcontinent in huge quantity. Even India's fossil record is impressive in which stromatolites, invertebrates, vertebrates and plant fossils are included.

India's geographical land area can be classified into the Deccan Traps, Gondwana and Vindhyan.

The Deccan Traps covers almost all of Maharashtra, a part of Gujarat, Karnataka, Madhya Pradesh and Andhra Pradesh marginally. During its journey northward after breaking off from the rest of Gondwana, the Indian Plate passed over a geologic hotspot, the Réunion hotspot, which caused extensive melting underneath the Indian Craton. The melting broke through the surface of the craton in a massive flood basalt event, creating the Deccan Traps. It is also thought that the Reunion hotspot caused the separation of Madagascar and India.

The Gondwana and Vindhyan include within its fold parts of Madhya Pradesh, Chhattisgarh, Odisha, Bihar, Jharkhand, West Bengal, Andhra Pradesh, Maharashtra, Jammu and Kashmir, Punjab, Himachal Pradesh, Rajasthan and Uttarakhand. The Gondwana sediments form a unique sequence of fluviatile rocks deposited in Permo-Carboniferous time. The Damodar and Sone river valleys and Rajmahal hills in eastern India contain a record of the Gondwana rocks.

The Geological Survey of India has published the List of National Geological Monuments in India.

Geology of Myanmar

The geology of Myanmar is shaped by dramatic, ongoing tectonic processes controlled by shifting tectonic components as the Indian plate slides northwards and towards Southeast Asia. Myanmar spans across parts of three tectonic plates (the Indian Plate, Burma microplate and Shan Thai Block) separated by north-trending faults. To the west, a highly oblique subduction zone separates the offshore Indian plate from the Burma microplate, which underlies most of the country. In the center-east of Myanmar, a right lateral strike slip fault extends from south to north across more than 1,000 km (620 mi). These tectonic zones are responsible for large earthquakes in the region. The India-Eurasia plate collision which initiated in the Eocene provides the last geological pieces of Myanmar, and thus Myanmar preserves a more extensive Cenozoic geological record as compared to records of the Mesozoic and Paleozoic eras. Myanmar is physiographically divided into three regions: the Indo-Burman Range, Myanmar Central Belt and the Shan Plateau; these all display an arcuate shape bulging westwards. The varying regional tectonic settings of Myanmar not only give rise to disparate regional features, but they also foster the formation of petroleum basins and a diverse mix of mineral resources.

Himalayacetus

Himalayacetus is an extinct genus of carnivorous aquatic mammal of the family Ambulocetidae. The holotype was found in Himachal Pradesh, India, (31.0°N 77.0°E / 31.0; 77.0: paleocoordinates 3.5°N 69.7°E / 3.5; 69.7) in what was the remnants of the ancient Tethys Ocean during the Early Eocene. This makes Himalayacetus the oldest archaeocete known, extending the fossil record of whales some 3.5 million years.Himalayacetus lived in the ancient coastline of the ancient Tethys Ocean before the Indian Plate had collided with the Cimmerian coast. Just like Gandakasia, Himalayacetus is only known from a single jaw fragment, making comparisons to other Ambulocetids difficult.

Himalayas

The Himalayas, or Himalaya (), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has many of Earth's highest peaks, including the highest, Mount Everest (Nepal/China). The Himalayas include over fifty mountains exceeding 7,200 m (23,600 ft) in elevation, including ten of the fourteen 8,000-metre peaks. By contrast, the highest peak outside Asia (Aconcagua, in the Andes) is 6,961 m (22,838 ft) tall.Lifted by the subduction of the Indian tectonic plate under the Eurasian Plate, the Himalayan mountain range runs west-northwest to east-southeast in an arc 2,400 km (1,500 mi) long. Its western anchor, Nanga Parbat, lies just south of the northernmost bend of Indus river. Its eastern anchor, Namcha Barwa, is just west of the great bend of the Yarlung Tsangpo River (upper stream of the Brahmaputra River). The Himalayan range is bordered on the northwest by the Karakoram and the Hindu Kush ranges. To the north, the chain is separated from the Tibetan Plateau by a 50–60 km (31–37 mi) wide tectonic valley called the Indus-Tsangpo Suture. Towards the south the arc of the Himalaya is ringed by the very low Indo-Gangetic Plain. The range varies in width from 350 km (220 mi) in the west (Pakistan) to 150 km (93 mi) in the east (Arunachal Pradesh). The Himalayas are distinct from the other great ranges of central Asia, although sometimes the term 'Himalaya' (or 'Greater Himalayas') is loosely used to include the Karakoram and some of the other ranges.

The Himalayas are inhabited by 52.7 million people, and are spread across five countries: Bhutan, China, India, Nepal and Pakistan. The Hindu Kush range in Afghanistan and Hkakabo Razi in Myanmar are normally not included, but they are both (with the addition of Bangladesh) part of the greater Hindu Kush Himalayan (HKH) river system; some of the world's major rivers – the Indus, the Ganges and the Tsangpo-Brahmaputra – rise in the Himalayas, and their combined drainage basin is home to roughly 600 million people. The Himalayas have a profound effect on the climate of the region, helping to keep the monsoon rains on the Indian plain and limiting rainfall on the Tibetan plateau. The Himalayas have profoundly shaped the cultures of the Indian subcontinent, with many Himalayan peaks considered sacred in Hinduism and Buddhism.

Indian subcontinent

The Indian subcontinent is a southern region and peninsula of Asia, mostly situated on the Indian Plate and projecting southwards into the Indian Ocean from the Himalayas. Geologically, the Indian subcontinent is related to the land mass that rifted from Gondwana and merged with the Eurasian plate nearly 55 million years ago. Geographically, it is the peninsular region in south-central Asia delineated by the Himalayas in the north, the Hindu Kush in the west, and the Arakanese in the east. Politically, the Indian subcontinent includes Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka.Sometimes, the geographical term 'Indian subcontinent' is used interchangeably with 'South Asia', although that last term is used typically as a political term and is also used to include Afghanistan. Which countries should be included in either of these remains the subject of debate.

Indo-Australian Plate

The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and surrounding ocean, and extends northwest to include the Indian subcontinent and adjacent waters. It was formed by the fusion of Indian and Australian plates approximately 43 million years ago.

List of earthquakes in India

The Indian subcontinent has a history of earthquakes. The reason for the intensity and high frequency of earthquakes is the Indian plate driving into Asia at a rate of approximately 47 mm/year. The following is a list of major earthquakes which have occurred in India, including those with epicentres outside India that caused significant damage or casualties in the country.

Prehistoric Mongolia

The climate of Central Asia became dry after the large tectonic collision between the Indian Plate and the Eurasian Plate. This impact threw up the massive chain of mountains known as the Himalayas. The Himalayas, Greater Khingan and Lesser Khingan mountains act like a high wall, blocking the warm and wet climate from penetrating into Central Asia. Many of the mountains of Mongolia were formed during the Late Neogene and Early Quaternary periods. The Mongolian climate was more humid hundreds of thousands of years ago.

Réunion hotspot

The Réunion hotspot is a volcanic hotspot which currently lies under the island of Réunion in the Indian Ocean. The Chagos-Laccadive Ridge and the southern part of the Mascarene Plateau are volcanic traces of the Réunion hotspot.The hotspot is believed to have been active for over 65 million years. A huge eruption of this hotspot 65 million years ago is thought to have laid down the Deccan Traps, a vast bed of basalt lava that covers part of central India, and opened a rift which separated India from the Seychelles Plateau. The Deccan Traps eruption coincided roughly with the nearly antipodal Chicxulub impactor and the Cretaceous–Paleogene extinction of the dinosaurs, and there is considerable speculation that the three events were related. As the Indian plate drifted north, the hotspot continued to punch through the plate, creating a string of volcanic islands and undersea plateaux. The Laccadive Islands, the Maldives, and the Chagos Archipelago are atolls resting on former volcanoes created 60–45 million years ago that subsequently submerged below sea level. About 45 million years ago the mid-ocean rift crossed over the hotspot, and the hotspot passed under the African Plate.

The hotspot appears to have been relatively quiet 45–10 million years ago, when activity resumed, creating the Mascarene Islands, which include Mauritius, Réunion, and Rodrigues. Mauritius and Rodrigues Ridge were created 8–10 million years ago, and Rodrigues and Réunion Islands in the last two million years. Piton de la Fournaise, a shield volcano on the southeastern corner of Réunion, is one of the most active volcanoes in the world, erupting last in February 2019.

South Asia

South Asia, or Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan SAARC countries and, for some authorities, adjoining countries to the west and east. Topographically, it is dominated by the Indian Plate, which rises above sea level as Nepal and northern parts of India situated south of the Himalayas and the Hindu Kush. South Asia is bounded on the south by the Indian Ocean and on land (clockwise, from west) by West Asia, Central Asia, East Asia, and Southeast Asia.

The current territories of Afghanistan, Bangladesh, Bhutan, Maldives, Nepal, India, Pakistan, and Sri Lanka form South Asia. The South Asian Association for Regional Cooperation (SAARC) is an economic cooperation organisation in the region which was established in 1985 and includes all eight nations comprising South Asia.South Asia covers about 5.2 million km2 (2 million mi2), which is 11.71% of the Asian continent or 3.5% of the world's land surface area. The population of South Asia is about 1.891 billion or about one fourth of the world's population, making it both the most populous and the most densely populated geographical region in the world. Overall, it accounts for about 39.49% of Asia's population, over 24% of the world's population, and is home to a vast array of people.In 2010, South Asia had the world's largest population of Hindus, Jains and Sikhs. It alone accounted for 98.47% population of global Hindus and 90.5% of global Sikhs. It also has the largest population of Muslims in the Asia-Pacific region which forms one third global Muslim population as well as over 35 million Christians and 25 million Buddhists.

Southeast Indian Ridge

The Southeast Indian Ridge (SEIR) is a mid-ocean ridge in the southern Indian Ocean. A divergent tectonic plate boundary stretching almost 6,000 km (3,700 mi) between the Rodrigues Triple Junction (25°S 70°E) in the Indian Ocean and the Macquarie Triple Junction (63°S 165°E) in the Pacific Ocean, the SEIR forms the plate boundary between the Australian and Antarctic plates since the Oligocene (anomaly 13).The SEIR is the spreading centre closest to the Kerguelen and Amsterdam–Saint-Paul hotspot.

The SEIR has an intermediate full spreading rate of 65 mm/yr, and, because Antarctica is virtually stationary, this results in a northward ridge migration of half that rate.

Spreading rates along the SEIR varies from 69 mm/yr near 88°E to 75 mm/yr near 120°E.

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Notable Himalayan quakes
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