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20-496: The Great Sumatran fault zone accommodates most of the strike-slip motion associated with the oblique convergence between the Indo-Australian plate and Eurasian plate The fault ends in the north near the city of Banda Aceh , which was devastated in the 2004 Indian Ocean earthquake . The Great Sumatran fault is part of the system where strain partitioning was first described in plate tectonics . The convergence between

40-470: Is a stub . You can help Misplaced Pages by expanding it . Indo-Australian plate The Indo-Australian plate is or was a major tectonic plate . It is in the process of separation into three plates, and may be currently separated into more than one plate. It contains the continent of Australia , its surrounding ocean and extends north-west to include the Indian subcontinent and the adjacent waters. It

60-540: Is a deformation zone between the Indian and Australian plates, with both earthquake and global satellite navigation system data indicating that India and Australia are not moving on the same vectors northward. In due course, some expect a well defined localized boundary to reform between the Indian and Australian plates. Studies show the Ninetyeast Ridge has active faulting along its whole length so that while

80-591: Is reflected in the Wallace line . The eastern part ( Australian plate ) is moving northward at the rate of 5.6 cm (2.2 in) per year while the western part ( Indian plate ) is moving only at the rate of 3.7 cm (1.5 in) per year due to the impediment of the Himalayas. In terms of the middle of India and Australia's landmasses, Australia is moving northward at 3 cm (1.2 in) per year relative to India. This differential movement has resulted in

100-558: The 2012 Indian Ocean earthquakes , suggest that the Indo-Australian plate may have already broken up into two or three separate plates due primarily to stresses induced by the collision of the Indo-Australian plate with Eurasia along what later became the Himalayas , and that the Indian plate and Australian plate may have been separate for at least 3  million years ago . Contemporary models suggest at present there

120-704: The Indian subcontinent , and the area east of the Chersky Range in eastern Siberia . It also includes oceanic crust extending westward to the Mid-Atlantic Ridge and northward to the Gakkel Ridge . The western edge is a triple junction plate boundary with the North American plate and Nubian plate at the seismically active Azores triple junction extending northward along the Mid-Atlantic Ridge towards Iceland . Ridges like

140-510: The Indo-Australian plate and the Sunda plate is not perpendicular to the plate boundary in this region. Instead, the two plates move at an oblique angle. Most of the convergent strain is accommodated by thrust motion at the plate boundary "megathrust" fault that defines the Sunda Trench . But the oblique motion (the part of the plate motion parallel to the plate boundary) is accommodated by

160-596: The Pacific plate . The Pacific plate sinks below the Australian plate and forms the Kermadec Trench and the island arcs of Tonga and Kermadec . New Zealand is situated along the southeastern boundary of the plate, which with New Caledonia makes up the southern and northern ends of the ancient landmass of Zealandia , which separated from Australia 85 million years ago. The central part of Zealandia sank under

180-714: The Sea of Okhotsk then south through Sakhalin Island and Hokkaido to the triple junction in the Japan Trench . But this simple view has been successfully challenged by more recent research. During the 1970s, Japan was thought to be located on the Eurasian plate at a quadruple junction with the North American plate when the eastern boundary of the North American plate was drawn through southern Hokkaido . New research in

200-569: The 1990s supported that the Okhotsk microplate was independent from the North American plate and a boundary with the Amurian microplate , sometimes described as "a division within the Eurasian plate" with an unknown western boundary. All volcanic eruptions in Iceland, such as the 1973 eruption of Eldfell , the 1783 eruption of Laki and the 2010 eruption of Eyjafjallajökull , are caused by

220-690: The Eurasian plate with the Arabian plate in the East Anatolian Fault Zone . The boundary between the North American plate and the Eurasian plate in the area around Japan has been described as "shifty". There are different maps for it based on recent tectonics, seismicity and earthquake focal mechanism . The simplest plate geometry draws the boundary from the Nansen Ridge through a broad zone of deformation in North Asia to

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240-555: The Great Sumatran fault, which runs along the volcanic Sunda Arc . The area between the main plate boundary thrust fault and the Great Sumatran fault forms a "sliver plate" that includes the entire offshore forearc, forearc islands, and the portion of Sumatra west of the Great Sumatran fault. This sliver plate is not a single rigid bloc, and the details of its internal deformation are under active investigation. Listed from northwest to southeast: This tectonics article

260-710: The Hindukush mountains. The northeast side of the Australian plate forms a subduction boundary with the Eurasian plate in the Indian Ocean between the borders of Bangladesh and Burma and to the southwest of the Indonesian islands of Sumatra and Borneo . Along the northern Ninety East Ridge under the Indian Ocean there appears to be a weakness zone where the Indian and Australian plates are going different ways. The subsidence boundary through Indonesia

280-573: The Mid-Atlantic ridge form at a divergent plate boundary . They are located deep underwater and very difficult to study. Scientists know less about ocean ridges than they do the planets of the solar system. There is another triple junction where the Eurasian plate meets the Anatolian sub-plate and the Arabian plate . The Anatolian sub-plate is currently being squeezed by the collision of

300-421: The North American and the Eurasian plates moving apart, which is a result of divergent plate boundary forces. The convergent boundary between the Eurasian plate and the Indian plate formed the Himalayas mountain range. The geodynamics of Central Asia is dominated by the interaction between the Eurasian plate and the Indian plate. In this area, many sub-plates or crust blocks have been recognized, which form

320-408: The ancient supercontinent of Gondwana . As the ocean floor broke apart, these land masses fragmented from one another, and for a time these centers were thought to be dormant and fused into a single plate. However, research in the early 21st century indicates plate separation of the Indo-Australian plate may have already occurred. The eastern side of the plate is the convergent boundary with

340-532: The compression of the former plate near its centre at Sumatra and the division into the separate Indian and Australian plates again. A third plate, known as the Capricorn plate , may also be separating off the western side of the Indian plate as part of the continued breakup of the Indo-Australian plate. There is good evidence that the Indo-Australian plate is in the process of separation into new plates. Recent studies, and evidence from seismic events such as

360-566: The sea. The southern margin of the plate forms a divergent boundary with the Antarctic plate . The western side is subdivided by the Indian plate that borders the Arabian plate to the north and the African plate to the south. The northern margin of the Indian plate forms a convergent boundary with the Eurasian plate , which constitutes the active orogenic process of the Himalayas and

380-534: The simplest explanation is that the Indian and Australian plates have already separated here, it remains possible that only the Capricorn plate has separated from them. Eurasian plate The Eurasian plate is a tectonic plate that includes most of Eurasia (a landmass consisting of the traditional continents of Asia and Europe ), with the notable exceptions of the Arabian Peninsula ,

400-434: Was formed by the fusion of the then Indian and the then Australian plates approximately 43 million years ago. The fusion happened when the mid-ocean ridge in the Indian Ocean , which separated the two plates, ceased spreading. Australia-New Guinea ( Mainland Australia , New Guinea , and Tasmania ), the Indian subcontinent , and Zealandia ( New Caledonia , New Zealand , and Norfolk Island ) are all fragments of

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