For many of us the oceans are symbols of eternity and immutability, but in fact they are not. Even the largest bodies of water on our planet do not last forever - they appear, develop, grow old, and then disappear. For example, look at the Tethys Ocean that existed between the ancient continents of Laurasia and Gondwana during the Late Paleozoic and Mesozoic era (320 to 66.5 million years ago). What is left of this mighty river basin? Only a few small seas - the Mediterranean, Black, and Caspian Seas and modest Persian Gulf.
Usually new oceans are born when continents break apart and hot magma pours into the faults, hardens and turns into the oceanic crust. This is how the Atlantic Ocean was created in the Mesozoic era when the supercontinent Pangaea split into southern Gondwana and northern Laurasia continents. Conversely, old oceans dye when continents collide, and the oceanic crust under their pressure sinks back into the mantle. The above mentioned Tethys disappeared when Africa and India approached Eurasia, not leaving any room for the water basin before separating these continents.
Obviously, even the oceans are subject to aging. Some of them are aging much faster than scientists assume. Recently, an Australian scientist Joao Duarte of Monash University and his colleagues found that the Atlantic Ocean does not have much left to live. This seems rather surprising because, according to the conventional opinion, this body of water is rather young. This is evidenced by the bottom of the subduction zones - linear stretches along which some blocks of the earth's crust dip under the others. In these areas the old crust goes into the mantle, giving place to a younger mantel. The younger mantle leaves the ground during spreading - a process of an impulsive and multiple shifts of the lithosphere of the oceanic crust and filling the freed space with magma generated in the mantle.
Interestingly, spreading zones exist in the Atlantic Ocean. This process takes place in the Mid-Atlantic Ridge, and is quite active.
June 25, 2013: M6.4 Quake - Northern Atlantic Ridge.
June 26, 2013: M4.6 Quake - Reykjanes Ridge.
But this indicates the young age of the ocean. In the Pacific there are many subduction zones, but quite a few places where spreading occurs, therefore it is considered old enough. However, as it turned out, the Atlantic Ocean is not that young if it has subduction zones. Read entire article
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