Oceanography

Scientists have discovered how ocean circulation is working in the current that flows around Antarctica by tracing the path of helium from underwater volcanoes. The details are published in Nature this week. The team, led by Alberto Naveira Garabato of the National Oceanography Centre, Southampton (formerly based at the University of East Anglia), has discovered a 'short-circuit' in the circulation of the world's oceans that could aid predictions about future climate change. This process in the Southern Ocean allows cold waters that sink to the abyss to return to the surface more rapidly…

Arctic sea ice is melting at a significantly faster rate than projected by even the most advanced computer models, a new study concludes. The research, by scientists at the National Center for Atmospheric Research (NCAR) and the University of Colorado's National Snow and Ice Data Center (NSIDC), shows that the Arctic's ice cover is retreating more rapidly than estimated by any of the 18 computer models used by the Intergovernmental Panel on Climate Change (IPCC) in preparing its 2007 assessments. This figure illustrates the extent to which Arctic sea ice is melting faster than projected by…

A major study has shed new light on the dim layer of the ocean called the "twilight zone"—where mysterious processes affect the ocean's ability to absorb and store carbon dioxide accumulating in our atmosphere. The results of two international research expeditions show that carbon dioxide — taken up by photosynthesizing marine plants in the sunlit ocean surface layer — does not necessarily sink to the depths, where it is stored and prevented from re-entering the atmosphere as a greenhouse gas. Instead, carbon transported to the depths on sinking marine particles is often consumed by animals…

As the national repository for geological material from the Southern Ocean, the Antarctic Marine Geology Research Facility at Florida State University houses the premier collection of Antarctic sediment cores -- and a hot new acquisition will offer an international team of scientists meeting there May 1-4 its best look yet at the impact of global warming on oceans worldwide. The remarkable new core was extracted during the recent Antarctic summer from record-setting drilling depths 4,214 feet below the sea floor beneath Antarctica's Ross Ice Shelf, the Earth's largest floating ice body.…

A new "black smoker" -- an undersea mineral chimney emitting hot, iron-darkened water that attracts unusual marine life -- has been discovered at about 8,500 feet underwater by an expedition currently exploring a section of volcanic ridge along the Pacific Ocean floor off Costa Rica. Expedition leaders have named their discovery the Medusa hydrothermal vent field. The researchers are working aboard WHOI's research vessel Atlantis, and the expedition is funded by the National Science Foundation. The researchers picked that name to highlight the presence of a pink form of the jellyfish order…

Scientists have found one of the largest fields of seafloor vents gushing super-hot, mineral-rich fluids on a mid-ocean ridge that, until now, remained elusive to the ten-year hunt to find them. "The discovery of the first active vents ever found on an ultraslow-spreading ridge is a significant milestone event," said Jian Lin, leader of a team of Woods Hole Oceanographic Institution (WHOI) scientists who participated in a Chinese expedition to the remote Southwest Indian Ridge in the Indian Ocean in February and March. The Southwest Indian Ridge is a spreading center between the African…

In 2008, scientists will, for the very first time, create a continual profile of ice thickness in the Artic, extending from the Canadian coast across the North Pole to Siberia. At the core of the project lies the crossing of the North Pole by zeppelin. The airship will be equipped with an electromagnetic sensor developed at the Alfred Wegener Institute for Polar and Marine Research. The project of French physician Jean-Louis Etienne is financed by the French oil company Total and will be presented in Berlin on April 5. Photo composition of the airship "Dirigeable," carrying the EM-Bird. The…

Oceanographers have completed an important step in constructing the first deep-sea observatory off the continental United States. Workers in the multi-institution effort laid 32 miles (52 kilometers) of cable along the Monterey Bay sea floor that will provide electrical power to scientific instruments, video cameras, and robots 3,000 feet (900 meters) below the ocean surface. The link will also carry data from the instruments back to shore, for use by scientists and engineers from around the world. An illustration of the MARS undersea observatory shows its cabled links. Credit: David…

A new study out of Alaska points out the impacts of climate change on marine ecosystems, and the need for increased research and stronger science based management to address future concerns. Studies by a team of scientists at the North Pacific Universities Marine Mammal Research Consortium http://www.marinemammal.org/ revealed that a sudden ocean climate change 30 years ago changed today’s Alaska marine ecosystems, and may be a leading factor in the decline of Alaska’s endangered western stock of Steller sea lions. Theories why the Steller sea lion population declined by more than 80…

Marine and freshwater organisms could be facing damage due to increasing levels of ultraviolet (UV) radiation, according to a United Nations (UN) commissioned review. The news is reported in the latest edition of the Royal Society of Chemistry journal Photochemical & Photobiological Sciences. Aquatic ecosystems produce over half the biomass of the Earth and are an integral part of the planet’s biosphere. The international team behind the review is worried that the depleted ozone layer has exposed these ecosystems to harmful levels of UV radiation, particularly in polar regions where…