TECTONIC PLATES
Introduction:
Plate Tectonics is a theory of geology that explains the observed evidence for large scale motions of the Earth’s Lithosphere. The theory encompassed and superseded the older theory of continental drift from the first half of the 20th century and the concept of seafloor spreading developed during the 1960's .It is the theory that the outer rigid layer of the earth (the lithosphere) is divided into a couple of dozen "plates" that move around across the earth's surface relative to each other.The movement is caused by the convection currents that roll over in the upper zone of the mantle. This movement in the mantle causes the plates to move slowly across the surface of the Earth.
Plates:
The lithosphere essentially "floats" on the asthenosphere and is broken-up into ten major plates: African, Antarctic, Australian, Eurasian, North American, South American, Pacific, Cocos, Nazca, and the Indian plates. These plates (and the more numerous minor plates) move in relation to one another at one of three types of plate boundaries: convergent (two plates push against one another), divergent (two plates move away from each other), and transform (two plates slide past one another). Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries (most notably around the the Pacific Ocean,forming the ring of fire) But the ones in this region include the African Plate,Eurasian,Arabian,Indian,Philippine,Somali,Capricorn,Australian,and Antarctic.
Plate Tectonics is a theory of geology that explains the observed evidence for large scale motions of the Earth’s Lithosphere. The theory encompassed and superseded the older theory of continental drift from the first half of the 20th century and the concept of seafloor spreading developed during the 1960's .It is the theory that the outer rigid layer of the earth (the lithosphere) is divided into a couple of dozen "plates" that move around across the earth's surface relative to each other.The movement is caused by the convection currents that roll over in the upper zone of the mantle. This movement in the mantle causes the plates to move slowly across the surface of the Earth.
Plates:
The lithosphere essentially "floats" on the asthenosphere and is broken-up into ten major plates: African, Antarctic, Australian, Eurasian, North American, South American, Pacific, Cocos, Nazca, and the Indian plates. These plates (and the more numerous minor plates) move in relation to one another at one of three types of plate boundaries: convergent (two plates push against one another), divergent (two plates move away from each other), and transform (two plates slide past one another). Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries (most notably around the the Pacific Ocean,forming the ring of fire) But the ones in this region include the African Plate,Eurasian,Arabian,Indian,Philippine,Somali,Capricorn,Australian,and Antarctic.
Past,Present And Future
Pangea was a supercontinent(the assembly of most or all of Earth’s coninental blocks or cratons to form one single landmass) that was surrounded by Panthalassa(a gigantic ocean) that existed during the late Paleozic and Early Mesozic eras a.It assembled from earlier continental units approximately 335 years ago,and it began to break apart 175 million years ago.
But before Pangea there was Nuna (1.8 billion years ago),then there was Rodinia (1 billion years ago),and then the most recent Pangea (300 million years). Scientists believe it (Pangea) broke apart for the same reason that the plates are moving today. The movement is caused by the convection currents that roll over in the upper zone of the mantle. This movement in the mantle causes the plates to move slowly across the surface of the Earth. About 200 million years ago Pangaea broke into two new continents Laurasia and Gondwanaland. Laurasia was made of the present day continents of North America (Greenland), Europe, and Asia. Gondwanaland was made of the present day continents of Antarctica, Australia, South America. The subcontinent of India was also part of Gondwanaland.The huge ocean of Panthalassa remained but the Atlantic Ocean was going to be born soon with the splitting of North America from the Eurasian Plate.
About 135 million years ago Laurasia was still moving, and as it moved it broke up into the continents of North America, Europe and Asia (Eurasian plate). Gondwanaland also continued to spread apart and it broke up into the continents of Africa, Antarctica, Australia, South America, and the subcontinent of India. Arabia started to separate from Africa as the Red Sea opened up.
The Atlantic, Indian, Arctic, and Pacific Oceans are all beginning to take shape as the continents move toward their present positions.
The plates are still moving today making the Atlantic Ocean larger and the Pacific Ocean smaller.
The Indian Subcontinent moved hundreds of miles in 135 million years at a great speed of four inches per year. The Indian plate crashed into the Eurasian plate with such speed and force that it created the tallest mountain range on Earth, the Himalayas!
In 50 million years the Atlantic Ocean will be much larger and the Pacific Ocean will be much smaller. North and South America will have moved farther west (California moving north) while Greenland will be located farther west but also farther north. The western part of Africa will rotate clockwise and crash into Europe causing great mountain building, while the far eastern region of Africa will rotate eastward toward the Arabian peninsula. Australia will move farther north into the tropics, while New Zealand will move to the south of Australia.
Scientists also think that 100 million years from now there will be Amasia (Over the next few hundred million years,the Arctic Ocean and the Caribbean Sea will disappear,and Asia will crash into the Americas forming yet another supercontinent that will stretch across much of the Northern Hemisphere.
Pangea was a supercontinent(the assembly of most or all of Earth’s coninental blocks or cratons to form one single landmass) that was surrounded by Panthalassa(a gigantic ocean) that existed during the late Paleozic and Early Mesozic eras a.It assembled from earlier continental units approximately 335 years ago,and it began to break apart 175 million years ago.
But before Pangea there was Nuna (1.8 billion years ago),then there was Rodinia (1 billion years ago),and then the most recent Pangea (300 million years). Scientists believe it (Pangea) broke apart for the same reason that the plates are moving today. The movement is caused by the convection currents that roll over in the upper zone of the mantle. This movement in the mantle causes the plates to move slowly across the surface of the Earth. About 200 million years ago Pangaea broke into two new continents Laurasia and Gondwanaland. Laurasia was made of the present day continents of North America (Greenland), Europe, and Asia. Gondwanaland was made of the present day continents of Antarctica, Australia, South America. The subcontinent of India was also part of Gondwanaland.The huge ocean of Panthalassa remained but the Atlantic Ocean was going to be born soon with the splitting of North America from the Eurasian Plate.
About 135 million years ago Laurasia was still moving, and as it moved it broke up into the continents of North America, Europe and Asia (Eurasian plate). Gondwanaland also continued to spread apart and it broke up into the continents of Africa, Antarctica, Australia, South America, and the subcontinent of India. Arabia started to separate from Africa as the Red Sea opened up.
The Atlantic, Indian, Arctic, and Pacific Oceans are all beginning to take shape as the continents move toward their present positions.
The plates are still moving today making the Atlantic Ocean larger and the Pacific Ocean smaller.
The Indian Subcontinent moved hundreds of miles in 135 million years at a great speed of four inches per year. The Indian plate crashed into the Eurasian plate with such speed and force that it created the tallest mountain range on Earth, the Himalayas!
In 50 million years the Atlantic Ocean will be much larger and the Pacific Ocean will be much smaller. North and South America will have moved farther west (California moving north) while Greenland will be located farther west but also farther north. The western part of Africa will rotate clockwise and crash into Europe causing great mountain building, while the far eastern region of Africa will rotate eastward toward the Arabian peninsula. Australia will move farther north into the tropics, while New Zealand will move to the south of Australia.
Scientists also think that 100 million years from now there will be Amasia (Over the next few hundred million years,the Arctic Ocean and the Caribbean Sea will disappear,and Asia will crash into the Americas forming yet another supercontinent that will stretch across much of the Northern Hemisphere.
Plate Boundary Interaction Results
Some interaction results include the East African Rift (divergent),The Eurasian Plate is subducting under the Philippine Mobile Belt at the Manila Trench (convergent),and the Owen fracture zone along the southeastern boundary of the Arabian plate (transform).
Some interaction results include the East African Rift (divergent),The Eurasian Plate is subducting under the Philippine Mobile Belt at the Manila Trench (convergent),and the Owen fracture zone along the southeastern boundary of the Arabian plate (transform).
Tectonic Plate Movements
(DIVERGENT) --The East African Rift (EAR) is an active continental rift zone in East Africa.It is a narrow zone that is a developing divergent tectonic plate boundary,in which the African Plate is in the process of splitting into two tectonic plates,called the Somali plate and Nubian plate.
-The Mid-Atlantic Ridge system which is a mid-ocean ridge, a divergent tectonic plate or constructive plate boundary located along the floor of the Atlantic Ocean,and part of the longest mountain range in the world and separates the North American and South American Plates in the west from the Eurasian and African Plate in the East. -The Gakkel Ridge is a slowly spreading ridge located in the arctic ocean.
(CONVERGENT BOUNDARY/SUBDUCTION ZONE)
-The Oceanic Philippine Sea Plate subducts beneath the Eurasia plate at the Ryukyu Trench.
-The oceanic Pacific Plate is subducting under the Indo-Australian Plate north and east of New Zealand, but the direction of subduction reverses south of the Alpine Fault where the Indo-Australian Plate starts subducting under the Pacific Plate.
(TRANSFORM BOUNDARIES)
-The Dead Sea Transform (DST) fault runs through the Jordan River Valley in the Middle East.
-The Owen Fracture Zone along the southeastern boundary of the Arabian Plate
(DIVERGENT) --The East African Rift (EAR) is an active continental rift zone in East Africa.It is a narrow zone that is a developing divergent tectonic plate boundary,in which the African Plate is in the process of splitting into two tectonic plates,called the Somali plate and Nubian plate.
-The Mid-Atlantic Ridge system which is a mid-ocean ridge, a divergent tectonic plate or constructive plate boundary located along the floor of the Atlantic Ocean,and part of the longest mountain range in the world and separates the North American and South American Plates in the west from the Eurasian and African Plate in the East. -The Gakkel Ridge is a slowly spreading ridge located in the arctic ocean.
(CONVERGENT BOUNDARY/SUBDUCTION ZONE)
-The Oceanic Philippine Sea Plate subducts beneath the Eurasia plate at the Ryukyu Trench.
-The oceanic Pacific Plate is subducting under the Indo-Australian Plate north and east of New Zealand, but the direction of subduction reverses south of the Alpine Fault where the Indo-Australian Plate starts subducting under the Pacific Plate.
(TRANSFORM BOUNDARIES)
-The Dead Sea Transform (DST) fault runs through the Jordan River Valley in the Middle East.
-The Owen Fracture Zone along the southeastern boundary of the Arabian Plate
Future Plate Movement
Since 10Ma-60Ma the Somali plate has been separating from the rest of Africa with an average rate of 25.4mm/year and moved 360 km across the rift with 10Ma.So at this rate 1 million years from now there will be infilling of a new ocean between Somali and Africa.
India is running into Asia at one and a half to two inches a year which is leading to earthquakes. When an unstoppable force like the Indian subcontinent crashes into an immovable object like Asia, the consequences may include the tallest mountains in the world.
Since 10Ma-60Ma the Somali plate has been separating from the rest of Africa with an average rate of 25.4mm/year and moved 360 km across the rift with 10Ma.So at this rate 1 million years from now there will be infilling of a new ocean between Somali and Africa.
India is running into Asia at one and a half to two inches a year which is leading to earthquakes. When an unstoppable force like the Indian subcontinent crashes into an immovable object like Asia, the consequences may include the tallest mountains in the world.
Earth’s Tectonic Plates have doubled their speed (August,29,2014) According to the latest study of plate movements,Earth's tectonic plates have been moving faster now than at any point in the last 2 billion years.But the result is controversial, since previous work seemed to show the opposite. If true, the result could be explained by another surprising recent discovery: the presence of more water within Earth's mantle than in all of the oceans combined. Because Plate tectonics is driven by the formation and destruction of oceanic crust , This crust forms where plates move apart, allowing hot, light magma to rise from the mantle below and solidify. Where plates are being pushed together, the crust can either rise up to form mountains or one plate is shoved under the other and is sucked back into the mantle.
‘Super Plume’ Slowly Splitting Africa in Two(August,11,2014):A new study by the Scripps Institute of Oceanography and the University of California at San Diego shows a massive upwelling of molten rock slowly splitting the African tectonic plate in two. Plumes of magma have long been thought to move the continents around, at least since 1912 when Alfred Wegener said that Africa and South America looked like they kind of fit together. But in East Africa, scientists have only recently begun to precisely figure out why two massive chunks of land are separating by a few millimeters every year.
‘Super Plume’ Slowly Splitting Africa in Two(August,11,2014):A new study by the Scripps Institute of Oceanography and the University of California at San Diego shows a massive upwelling of molten rock slowly splitting the African tectonic plate in two. Plumes of magma have long been thought to move the continents around, at least since 1912 when Alfred Wegener said that Africa and South America looked like they kind of fit together. But in East Africa, scientists have only recently begun to precisely figure out why two massive chunks of land are separating by a few millimeters every year.