A Guyot ( also bottom tip ) is flattened at the top Seamount, which is the cone of an extinct undersea volcano. It is therefore in Guyots to frustoconical single mountains or volcanic islands with steep slopes and plateau peaks which can be ( at deep-sea trenches ) up to several thousand meters below sea level. Worldwide, there are about 10,000 seamounts.
Origin of guyots
Seamounts and guyots are produced at the divergent plate boundaries of the mid-ocean ridges or within an oceanic plate under the hot-spot volcanism. The movement of the oceanic crust during the seafloor spreading volcanoes lose contact with their Magmenquelle and Magmenförderung goes out. In contrast to the seamounts initially extend beyond many of the later seamounts on the ocean surface, and are thus subject to the abrasive action of the surf. When the volcano from the mid-ocean ridges, the growing cold seabed contracts and the volcano sinks, while flattening the erosion through the surf the fragile tip of the basaltic volcanic loose material composition existing mountain to a plateau. This erosion platform can be several tens of kilometers wide.
Guyots as evidence of plate tectonics
The Guyots served as one of the evidence of plate tectonics, because before deep-sea trenches, where the oceanic crust dives under another plate ( subduction ), seamounts were found that were slightly tilted, so that the plateau tilted towards the deep sea channel.
Were discovered deepwater knolls in 1941 by Harold Murray in the Gulf of Alaska. First described it in 1946 by Harry Hammond Hess ( 1906-1969 ), an American geologist at Princeton University. He felt about 100 of these seamounts in the Pacific on when he during the Second World War, the USS Cape Johnson (AP -172 ), a troop transport ship, commanded. With the help of powerful sonar that type of vessel he created topographic height profiles of the seabed. He discovered the Guyots and guessed correctly that it is flattened by erosion submarine volcanoes with them. He named in 1946 after the geographer Arnold Henry Guyot ( 1807-1884 ), founder of the Geology Department of the University of Princeton. With the help of these and many other observations and discoveries in the following years, he formulated the hypothesis of seafloor spreadings and published them in 1962 under the title History of Ocean Basins ( The origin of the ocean basins ). He had recognized and described the movement of tectonic plates ( Mobilism ).