Related topics: ocean · carbon dioxide · seafloor · sea floor · ocean floor

Earthquake depth impacts potential tsunami threat

Earthquakes of similar magnitude can cause tsunamis of greatly varying sizes. This commonly observed, but not well-understood phenomenon has hindered reliable warnings of local tsunamis.

Unlocking the biogeographical secrets of deep-sea limpets

Researchers from The Hong Kong University of Science and Technology (HKUST) and Hong Kong Baptist University (HKBU) have decoded for the first time the demographic history, genetic structure, and population connectivity of ...

Marine microbe contains multitudes

A deep dive into microbial genomics reveals one bacterial species is made of four ecologically distinct groups with different lifestyles.

Intensified water cycle slows down global warming, new study finds

A new study led by scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, in collaboration with scientists at Princeton University, shows that the intensification of global hydrological ...

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Deep sea

The deep sea, or deep layer, is the lowest layer in the ocean, existing below the thermocline, at a depth of 1000 fathoms (1828 m) or more. Little or no light penetrates this area of the ocean, and most of its organisms rely on falling organic matter produced in the photic zone for subsistence. For this reason scientists assumed life would be sparse in the deep ocean, but virtually every probe has revealed that, on the contrary, life is abundant in the deep ocean.

From the time of Pliny until the expedition in the ship Challenger between 1872 and 1876 to prove Pliny wrong; its deep-sea dredges and trawls brought up living things from all depths that could be reached. Perhaps one day man will be more like aqua man, and roam the ocean depths with the fish creatures alike. Yet even in the twentieth century scientists continued to imagine that life at great depth was insubstantial, or somehow inconsequential. The eternal dark, the almost inconceivable pressure, and the extreme cold that exist below one thousand meters were, they thought, so forbidding as to have all but extinguished life. The reverse is in fact true....(Below 200 meters) lies the largest habitat on earth.

In 1960 the Bathyscaphe Trieste descended to the bottom of the Marianas Trench near Guam, at 35,798 feet (10,911 meters), the deepest spot on earth. If Mount Everest were submerged there, its peak would be more than a mile beneath the surface. At this great depth a small flounder-like fish was seen moving away from the bathyscaphe's spotlight. The Japanese research submersible Kaiko was the only vessel capable of reaching this depth, and it was lost in 2003.

We know more about the moon than the deepest parts of the ocean. Until the late 1970s little was known about the possibility of life on the deep ocean floor but the the discovery of thriving colonies of shrimp and other organisms around hydrothermal vents changed that. Before the discovery of the undersea vents, all life was thought to be driven by the sun. But these organisms get their nutrients from the earth's mineral deposits directly. These organisms thrive in completely lightless and anaerobic environments, in highly saline water that may reach 300 °F (149 °C), drawing their sustainance from hydrogen sulfide, which is highly toxic to all terrestrial life. The revolutionary discovery that life can exist without oxygen or light significantly increases the chance of there being life elsewhere in the universe. Scientists now speculate that Europa, one of Jupiter's moons, may have conditions that could support life beneath its surface which is speculated to be a liquid ocean beneath the icy crust.

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