On the 68th cruise of the German research vessel METEOR an international team of scientists under the lead of Andrea Koschinsky, Professor of Geosciences at IUB, registered 407 °C at a hydrothermal vent as the highest temperature on record measured at the ocean bottom.
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May
22, 2006]
Using a special temperature sensor operated by a deep-sea robot the scientists registered the record temperature in 3000 m water depth at a so-called „black smoker“, a hydrothermal deep-sea vent with a characteristic particle plume in the discharge water. Moreover, the boiling fluids emitted by the vent were filmed. The super-hot vent was discovered at 5 °S at the Mid-Atlantic Ridge, where the African and the South American continental plates drift apart 4 cm per year, causing increased volcanic activity. Normally the temperature of the circulating seawater cooling the volcanoes emerging in this area does not exceed a maximum of about 350 °C when welling out of the sea floor.
Maximum deep-sea water temperatures up to 402 °C so far have only been observed in the Pacific. “This increase of the record by 5 °C is significant as 407 °C at 3000 m depth marks the critical temperature, where water is no longer a fluid but reaches the state of “critical vapor,“ says cruise leader Koschinsky. “This special state of aggregation differs markedly from liquid water in the way it leaches materials such as metals from the surrounding bedrock. The result of this process are super-hot solutions of highly unusual composition.“ According to geologist Prof. Colin Devey of the Kiel-based Leibniz Institute of Marine Sciences the unusually high water temperature indicates a comparatively recent start of the volcanic activity, which is also corroborated by new lava outcrops observed in the same sea floor area.
The Meteor expedition M68/1 from April 27 to June 2, 2006, explores the correlation between volcanism, water circulation inside and above the sea floor and hydrothermal vent organism communities. In addition to the super-hot vent it also discovered other, to date uncharted hot deep-sea wells. This was facilitated by combining the abilities of the autonomous deep-sea vehicle „ABE“ specially developed by Woods Hole Oceanographic Institute for locating hot vents and the remotely operated vehicle „QUEST 5“ developed by the University of Bremen for sea floor charting and sampling. The expedition is part of the DFG (German Research Foundation) Priority Program 1144 „From Mantle to Ocean: Energy-, Material- and Life-cycles at Spreading Axes” and is co-financed by the U. S. National Oceanographic & Atmospheric Administration.
For further information see: Prof. Dr. Andrea Koschinsky: www.iu-bremen.de/directory/akoschinsky/index.php Prof. Dr. Colin Devey: www.ifm-geomar.de/index.php?id=cdevey DFG Priority Program 1144: www.deridge.de Autonomous Benthic Explorer „ABE“: www.whoi.edu/institutes/instruments/abe.htm Remotely Operated Vehicle „QUEST 5“: www.rcom.marum.de/English/QUEST_4000_m.html
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