Atmospheric nuclear testing in the 1950s and 1960s produced significant amounts of uranium-236. This isotope readily dissolves in seawater, giving researchers today the opportunity to investigate ocean currents by monitoring its concentration. Until recent advances in heavy ion mass spectrometry, however, this type of detection was considered impossible.
The rapid retreat of sea ice in the Arctic has attracted the attention of top naval officials who have recently held an Arctic Summit at the Office of Naval Research to discuss their reponse to what will likely be a increased volume of human activity in the region. Although the meeting did not discuss policy, it did highlight the many potential areas of impact, from oil drilling to tourism.
Gaping crevasses that penetrate upward from the bottom of the largest remaining ice shelf on the Antarctic Peninsula make it more susceptible to collapse, according to researchers who spent the last four Southern Hemisphere summers studying the massive Larsen C Ice Shelf. But the team, which used radar technology to study the composition of the ice shelf, also identified structures that contributed to the shelf’s resilience.
Vast amounts of methane are stored under the ocean floor, and anaerobic oxidation of methane coupled to sulfate respiration prevents the release of this gas. Though discovered decades ago, the mechanism for how microorganisms performed this reaction has remained a mystery. According to recent findings, a single microorganism can do this on its own, and does not need to be carried out in collaboration with a bacterium as previously thought.
To keep cellular systems running all cells need fuel. For certain ocean-dwelling microorganisms, methane can be such a fuel. But researchers studying these creatures had previously assumed that the methane they consumed was used as a carbon source. However, recent studies have surprisingly shown that is not the case and will force scientists to reevaluate the microorganisms’ role in inactivating environmental methane.
In the future, warmer waters could significantly change ocean distribution of populations of phytoplankton, tiny organisms that could have a major effect on climate change. Researchers have recently shown that by the end of the 21st century, warmer oceans will cause populations of these marine microorganisms to thrive near the poles and shrink in equatorial waters.
A new NASA study shows that from 1978 to 2010 the total extent of sea ice surrounding Antarctica in the Southern Ocean grew by roughly 6,600 square miles every year, an area larger than the state of Connecticut. However, this growth rate is not nearly as large as the decrease in the Arctic, which has scientists questioning the reasons for the growth. Atmospheric circulation may be one cause.
A research team from the University of California, Santa Barbara and Portland State University has retrieved a sensor containing previously unavailable data about changes in chemistry or acidification in the remote waters of McMurdo Sound in Antarctica. The device collected data through June, when the battery expired in the harsh polar sea.
A U.K. research team has recently determined that the geometry of channels beneath the ice can be a strong control on ice behaviour, temporarily hiding the signals of retreat. The findings, which provide the first simulation of past ice-sheet retreat and collapse over a ten thousand year period in Antarctica, shed new light on what makes ice stable or unstable and will help refine predictions of future ice extent and global sea-level rise, the researchers say.
While the North Pole has been losing sea ice over the years, the water nearest the South Pole has been gaining it. Antarctic sea ice hit a record 7.51 million square miles in September, just days after reports of the biggest loss of Arctic sea ice on record. Climate change skeptics have seized on this example, but scientists say the skeptics are misinterpreting what's happening and why.
Water does not forget, says Prof. Boris Koch, a chemist at the Alfred Wegener Institute for Polar and Marine Research. With the combination of some new techniques, Koch and colleagues can now identify and retrace some of the biomolecular tracks left by living organism. This dissolved organic matter, detectable with mass spectrometry, is one of the largest active, organic carbon reservoirs on earth.
Our greenhouse gas emissions up to now have triggered an irreversible warming of the Earth that will cause sea levels to rise for thousands of years to come, new research has show. The results come from a study which sought to model sea-level changes over millennial timescales, taking into account all of the Earth's land ice and the warming of the oceans.
Emerging from the investigation of a mysterious nitrogen-fixing microbe that has a very small genome, an international team of investigators has found that certain type of photosynthetic bacteria not only provides nitrogen to its host single-cell algae, it appears now to be the most widespread nitrogen-fixing organism in the oceans.
According to a new study that measured the rate at which bacteria in the Gulf of Mexico ate the oil and gas discharged by the broken Deepwater Horizon well, at least 200,000 tons of hydrocarbons were consumed by gulf bacteria over a five month period.
Scientific deep sea drilling vessel “Chikyu” has set a world new record by drilling down and obtaining rock samples from deeper than 2,111 m (6,926 feet) below the seafloor off Shimokita Peninsula of Japan in the northwest Pacific Ocean. “Chikyu” is designed to reach the deeper part of the Earth such as the mantle, the plate boundary seisomogenic zones and the deep biosphere.
A new underwater explorer hit the seas this summer, armed with cameras, strobes and sonar and charged with being a protector of sorts to a half-billion dollar resource—the Atlantic scallop catch. Developed by a former scalloper and researchers at the Woods Hole Oceanographic Institution, the stainless steel Seahorse gives marine scientists a look at the seafloor they’ve never had before and offers uses beyond policing scallop grounds.
Up to 4% of the methane on Earth comes from the ocean’s oxygen-rich waters, but scientists have been unable to identify the source of this potent greenhouse gas. Now researchers report that they have found the culprit: a bit of "weird chemistry" practiced by the most abundant microbes on the planet.
Today, marine fish are largely surveyed using selective and invasive methods mostly limited to commercial species, and restricted to areas with favorable conditions. Researchers in Denmark, however, have shown that seawater contains DNA from animals such as fish and whales. They have successfully used this trace presence, using as little as half a liter of water, to establish a method for tracking species.
Charles Darwin hypothesized in 1880 that most species could not disperse across the Eastern Pacific Barrier, an uninterrupted 4,000-mile stretch of water with depths of up to 7 miles that separates the central from the eastern Pacific Ocean. Scientists have confirmed this hypothesis for many species, but recent research by Penn State University is the first to determine its effect on coral.
If recent research by a team from the U.S. and Germany is correct, previous estimates about the total mass of all life on planet Earth will have to be reduced by about one third. The revision came about after researchers realized that previous drill cores, upon which the estimate are based, were recovered close to shore or in nutrient-rich areas. However, much of the ocean is a “desert”, supporting very little life.
The National Snow and Ice Data Center reported Monday that the extent of Arctic sea ice shrank to 1.58 million square miles and is likely to melt more in the coming weeks. That breaks the old record of 1.61 million square miles set in 2007. Data center scientist Ted Scambos said the melt can be blamed mostly on global warming from man-made emissions of greenhouse gases.
At this week’s American Chemical Society meeting, a number of scientists reported progress toward workable solutions for extracting uranium for nuclear power from seawater, which holds at least four billion tons of the material. The concept, which dates back 40 years, is seen as a crucial step for making future nuclear power operations viable.
The average temperature of oceans is rising along with the temperatures in the atmosphere, raising concern that ice-like compounds called methane hydrates could dissolve this powerful greenhouse gas into the atmosphere. An expedition to Spitsbergen in the high Arctic could help answer this question.
This week researchers have reported the first detailed data on methane-exhaling microbes that live deep in the cracks of hot undersea volcanoes. As evidence builds that a large amount of biomass exists in Earth’s subsurface, the scientists’ major goal was to test results of predictive computer models and to establish the first environmental hydrogen threshold for these extreme microbes.
The Southern Ocean is an important carbon sink. Around 40% of the annual global carbon dioxide emissions absorbed by the world’s oceans enter through this region. A team of British and Australian scientists has recently discovered how this carbon is drawn down from the surface of the Southern Ocean to the deep waters beneath.