Eurasian plate | |
---|---|
Type | Major |
Approximate area | 67,800,000 km2 (26,200,000 sq mi) [1] |
Movement1 | South |
Speed1 | 7–14 mm (0.28–0.55 in)/year |
Features | Asia (excluding the Arabian Peninsula, the Indian subcontinent, and the area east of the Chersky Range in eastern Siberia), Europe (including a part of Iceland), Arctic Ocean, Atlantic Ocean |
1Relative to the African 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, 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. [2] [3] Ridges like 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. [4]
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 the Eurasian plate with the Arabian plate in the East Anatolian Fault Zone. [5] [6]
The boundary between the North American plate and the Eurasian plate in the area around Japan has been described as "shifty". [7] 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 the Sea of Okhotsk then south through Sakhalin Island and Hokkaido to the triple junction in the Japan Trench. [8] 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 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"[ additional citation(s) needed ] with an unknown western boundary. [9] [10]
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 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 the Central Asian and the East Asian transit zones. [11]
The North American plate is a tectonic plate containing most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of 76 million km2 (29 million sq mi), it is the Earth's second largest tectonic plate, behind the Pacific plate.
The African plate, also known as the Nubian plate, is a major tectonic plate that includes much of the continent of Africa and the adjacent oceanic crust to the west and south. It is bounded by the North American plate and South American plate to the west ; the Arabian plate and Somali plate to the east; the Eurasian plate, Aegean Sea plate and Anatolian plate to the north; and the Antarctic plate to the south.
The Arabian plate is a minor tectonic plate in the Northern and Eastern Hemispheres.
The Anatolian sub-plate is a continental tectonic plate that is separated from the Eurasian plate and the Arabian plate by the North Anatolian Fault and the East Anatolian Fault respectively. Most of the country of Turkey is located on the Anatolian plate. Most significant earthquakes in the region have historically occurred along the northern fault, such as the 1939 Erzincan earthquake. The devastating 2023 Turkey–Syria earthquakes occurred along the active East Anatolian Fault at a strike-slip fault where the Arabian plate is sliding past the Anatolian plate horizontally.
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 had begun rifting by 96 million years ago and completely separated a while after this, some believing as recently as 45 million years ago, but most accepting presently that this had occurred by 60 million years ago.
A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can be described according to the types of plate margin that meet at them. Of the ten possible types of triple junctions only a few are stable through time. The meeting of four or more plates is also theoretically possible, but junctions will only exist instantaneously.
The Okhotsk microplate is a proposed minor tectonic plate covering the Kamchatka Peninsula, Magadan Oblast, and Sakhalin Island of Russia; Hokkaido, Kantō and Tōhoku regions of Japan; the Sea of Okhotsk, as well as the disputed Kuril Islands.
The Gorda Ridge, is a tectonic spreading center, located roughly 200 kilometres (120 mi) off the northern coast of California and southern Oregon. Running northeast to southwest, the region is roughly 300 kilometres (190 mi) in length. The ridge is broken into three segments: the northern ridge, central ridge, and the southern ridge, which includes the Escanaba Trough.
The geology of Turkey is the product of a wide variety of tectonic processes that have shaped Anatolia over millions of years, a process which continues today as evidenced by frequent earthquakes and occasional volcanic eruptions.
The Azores triple junction (ATJ) is a geologic triple junction where the boundaries of three tectonic plates intersect: the North American plate, the Eurasian plate and the African plate. This triple junction is located along the Mid-Atlantic Ridge (MAR) amidst the Azores islands, nearly due west of the Strait of Gibraltar. It is classified as an R-R-R triple junction of the T type, as it is an intersection of the Mid-Atlantic Ridge running north–south and the Terceira Rift which runs east-southeast.
The Terceira Rift is a geological rift located amidst the Azores islands in the Atlantic Ocean. It runs between the Azores triple junction to the west and the Azores–Gibraltar Transform Fault to the southeast. It separates the Eurasian plate to the north from the African plate to the south. The Terceira Rift is named for Terceira Island through which it passes. It crosses Terceira Island as a prominent ESE-WNW fissure zone.
The Azores–Gibraltar transform fault (AGFZ), also called a fault zone and a fracture zone, is a major seismic zone in the eastern Atlantic Ocean between the Azores and the Strait of Gibraltar. It is the product of the complex interaction between the African, Eurasian, and Iberian plates. The AGFZ produced these large-magnitude earthquakes and, consequently, a number of large tsunamis: 1755 Lisbon, 1761 Lisbon, 1816 North Atlantic, 1941 Gloria Fault earthquake, 1969 Horseshoe and 1975.
The Aden–Owen–Carlsberg triple junction (AOC), also known as the Arabia–India–Somalia triple junction, is a triple junction that connects the Aden Ridge, Owen Fracture Zone, and Carlsberg Ridge in the northwest Indian Ocean. It has been described as one of only three RRF (ridge–ridge–fault) triple junctions on Earth, besides the Azores triple junction and Chile triple junction. However, because the fault arm of such unstable triple junctions tend to evolve into a spreading centre, all three cases have quickly evolved into stable RRR triple junctions.
The East Anatolian Fault is a ~700 km long major strike-slip fault zone running from eastern to south-central Turkey. It forms the transform type tectonic boundary between the Anatolian sub-plate and the northward-moving Arabian plate. The difference in the relative motions of the two plates is manifest in the left lateral motion along the fault. The East and North Anatolian faults together accommodate the westward motion of the Anatolian sub-plate as it is squeezed out by the ongoing collision between the Arabian plate and the Eurasian plate.
The Karlıova triple junction is a geologic triple junction of three tectonic plates: the Anatolian plate, the Eurasian plate and the Arabian plate.
This is a list of articles related to plate tectonics and tectonic plates.
The 1949 Karlıova earthquake occurred at 18:44 UTC on 17 August with an epicenter near Karlıova in Bingöl Province, Eastern Anatolia Region of Turkey. It had an estimated magnitude of 6.7, a maximum felt intensity of X (Extreme) on the Mercalli intensity scale, and caused 320–450 casualties and destroyed 3,500 buildings.
The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth.
The geological deformation of Iceland is the way that the rocks of the island of Iceland are changing due to tectonic forces. The geological deformation help to explain the location of earthquakes, volcanoes, fissures, and the shape of the island. Iceland is the largest landmass situated on an oceanic ridge. It is an elevated plateau of the sea floor, situated at the crossing of the Mid-Atlantic Ridge and the Greenland-Iceland-Scotland ridge. It lies along the oceanic divergent plate boundary of North American Plate and Eurasian Plate. The western part of Iceland sits on the North American Plate and the eastern part sits on the Eurasian Plate. The Reykjanes Ridge of the Mid-Atlantic ridge system in this region crosses the island from southwest and connects to the Kolbeinsey Ridge in the northeast.
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: CS1 maint: multiple names: authors list (link)The Anatolian tectonic block (sub-plate) is being affected by converging plate movements that occur between the Arabian-African and Eurasian plates (e.g. Armijo, Meyer, Hubert, & Barka, Citation1999; Bozkurt, Citation2001; Jackson & McKenzie, Citation1984; Le Pichon, Chamot-Rooke, Lallemant, Noomen, & Veis, Citation1995; McKenzie, Citation1972, 1978; Şengör, Citation1979, 1980; Sengör, Görür, & Saroglu, Citation1985; Taymaz, Jackson, & McKenzie, Citation1991). As a result of this collision, the North Anatolian (NAF) and East Anatolian (EAF) transform faults have been formed. The Anatolian sub-plate is bounded to the north and east by these faults. The impingement started to move the sub-plate westward and resulted compression and uplifts near the Karlıova triple junction in the Eastern Anatolia. As a result of anti-clockwise rotational movement of the Anatolian sub-plate in a westward direction four different neotectonic regions have been formed namely: (1) East Anatolian compressional region, (2) North Anatolian region, (3) Central Anatolian 'ova' region and (4) West Anatolian extensional region (Sengör et al., Citation1985).
Hence, the problem: geodetic models imply a plate boundary between Japan and Eurasia, but published geological and seismological evidence does not support placing it in the Japan Sea or at the ISTL. If, as studies show, almost half of the convergence between North America and Eurasia is taken up in Hokkaido and across N Japan, the small amount of remaining convergence may be difficult to distinguish given the large elastic response in the upper plate (N Honshu) after the 2011 Tohoku-oki (M9.0) earthquake, and strong coupling at the megathrust. To draw such a plate boundary on tectonic maps implies a degree of certainty about its location which is unfounded