Africa was once the center of Pangaea, the massive supercontinent that existed about million years ago. As a result, the African plate has three mid-ocean ridges divergent boundaries along the eastern, southern, and most of the western sides. At these boundaries, the continent shifts away, and hot magma from the volcanoes seeps up, creating new seafloor. On the northern side is the convergent boundary where the African plate is subducting below the Eurasian plate.
The African plate seems to be splitting apart faster than what Geologists have imagined. The tear, which continues to grow is making the scientific community debate whether African is in fact made of two tectonic plates, or if the continent is splitting in two. A recent paper published to Nature Communications showed that large portions of the African Plate have disappeared over the past million years. Stretching roughly around Antarctica was once part of Gondwanaland, the southern half of the Pangaean supercontinent.
Gradually, Antarctica split away from the other continents and moved southwards and reached its current location about million years ago. Tectonically, the Antarctic Plate can be separated into two distinct components: the West Antarctic, comprised of numerous partially-submerged microplates, and the large craton of the East Antarctic, which is divided by the West Antarctic Rift System.
At about It was formed out of a merger of the Indian Plate and Australian Plate about million years ago. Indo-Australian Plate stretches from the continent of Australia to the Indian subcontinent. Indo-Australian Plate is currently moving to the north-east at about cm a year. One of the forces that drive the movement is the subduction along its northern sides as the plate is subducted along the Pacific Ring of Fire.
However, the upper mantle of the plate is moving at a slower rate — about cm a year. Oceanic plates are formed by divergent plate boundaries. Continental plates, meanwhile, are formed primarily by convergent plate boundaries.
These zones represent areas where oceanic plates collide with and plunge underneath continental plates — a process called subduction. Skip to content. Table of Contents show. Pacific Plate. North American Plate. Eurasian Plate. African Plate. Antarctic Plate. Indo-Australia Plate. South American Plate. What's the size of the 7 major tectonic plates?
Pacific Plate Pacific major plate is the largest which underlies the Pacific Ocean. African Plate The African plate contains the whole continent of Africa as well as the surrounding oceanic crust of the Atlantic Ocean. Antarctic Plate The Antarctic plate holds the entire continent of Antarctica including its surround oceanic crust. It's estimated that the Antarctica major plate moves about 1 cm per year.
I found it very helpful… I used this information to teach my year seven class. It would be nice if you also showed the oceans in the plate pictures. Leave a Reply Cancel reply Your email address will not be published. At divergent boundaries, plates separate, forming a narrow rift valley.
Here, geysers spurt super-heated water, and magma, or molten rock, rises from the mantle and solidifies into basalt, forming new crust. Thus, at divergent boundaries, oceanic crust is created.
In Iceland, one of the most geologically active locations on Earth, the divergence of the North American and Eurasian plates along the Mid-Atlantic Ridge can be observed as the ridge rises above sea level. At convergent boundaries, plates collide with one another.
The collision buckles the edge of one or both plates, creating a mountain range or subducting one of the plates under the other, creating a deep seafloor trench. At convergent boundaries, continental crust is created and oceanic crust is destroyed as it subducts, melts, and becomes magma.
Convergent plate movement also creates earthquakes and often forms chains of volcanoes. The highest mountain range above sea level, the Himalayas, was formed 55 million years ago when the Eurasian and Indo-Australian continental plates converged. The Mediterranean island of Cyprus formed at a convergent boundary between the African and Eurasian plates.
Hardened mounds of lava, called pillow lavas, were once on the bottom of the ocean where this convergence occurred, but have been pushed up and are now visible at the surface. Given the limited technology and data set available to Marie Tharp and Bruce Heezen in the ss, what could be potential limitations of the Tharp-Heezen map?
Potential limitations or inaccuracies in the Tharp-Heezen map could include the following: general locations of geologic features were accurate but specific landscapes were not and could have been misrepresented through artistic interpretation ; the map was vertically exaggerated to make features visible ; gentle slopes may have been overlooked or underestimated ; inaccuracy due to merging maps and data of different scales and precision, often collected by different organizations.
At which type of tectonic boundary is oceanic crust created? At which type of tectonic boundary is oceanic crust destroyed? Provide at least one example where each type of boundary is found on the Earth. Oceanic crust is created at divergent boundaries , such as the mid-ocean ridge.
Oceanic crust is destroyed at convergent boundaries where subduction results in a trench, such as the Mariana Trench or Cayman Trough. If an oceanic and continental plate converged, the denser oceanic plate would subduct under the continental plate. Also called an extensional boundary. Some hot spots produce volcanoes.
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