Taxonomy term

oceanography

Hundreds of methane seeps discovered along the U.S. East Coast

The release of methane from seafloor sediments may have a significant influence on global climate, but the ubiquity and stability of such pockets is not well understood. Now the discovery of hundreds of methane seeps on the seafloor along the U.S. East Coast suggests that such reservoirs may be more common along passive margins than previously thought. The easily accessible region may prove to be an ideal natural laboratory for studying how such seafloor methane may influence water temperatures and ultimately climate.

07 Dec 2014

Massive icebergs scoured Arctic seafloor

In August 1990, the R/V Polar­stern departed Tromsø, Norway, to investigate the ocean bottom bathymetry of the Fram Strait between Greenland and Svalbard. More than 20 years later, marine geologist Jan Erik Arndt and his colleagues at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany, were reviewing data from the cruise when they discovered something new — the deepest evidence of iceberg scouring ever found.

13 Nov 2014

Boron proxies detail past ocean acidification

Pockmarked plankton shells and dead coral are becoming the hallmark images of ocean acidification. But this isn’t the first time seawater has dropped on the pH scale. Based on models of seawater chemistry, the ocean acidity during the Paleocene-Eocene Thermal Maximum (PETM), beginning about 56 million years ago, is the closest-known analog to today. Now, researchers using boron proxies preserved in microfossils to reconstruct surface-ocean chemistry suggest that acidification was more extensive and lasted longer than previously thought, although the PETM conditions still don’t outpace the current rate of ocean acidification.

25 Sep 2014

R.I.P. Nereus

Nereus, the United States’ only full-ocean-depth submersible, was lost at sea on May 10, 2014. The unmanned and remotely operated vehicle was capable of reaching the hadal zone, the ocean region 6 to 11 kilometers deep, and was designed, built and operated by Woods Hole Oceanographic Institution (WHOI) in Massachusetts. Nereus was at a depth of 9,990 meters in the Kermadec Trench off New Zealand, the fifth-deepest ocean trench in the world, when it lost contact with researchers aboard the R/V Thomas G. Thompson. Debris later surfaced, which was recovered and determined to be the remains of the vessel. The debris indicated a catastrophic implosion, likely of one or more of the vehicle’s ceramic buoyancy spheres.
 

04 Sep 2014

Nutrient runoff feeding Baltic Sea dead zone

Low-oxygen, or hypoxic, deep waters now extend over an area of about 60,000 square kilometers in the Baltic Sea, a tenfold increase compared to 115 years ago, according to a recent study published in Proceedings of the National Academy of Sciences. The hypoxic zone has fluctuated substantially in that period, but much of the expansion has occurred in recent decades as a result of large inputs of nutrients like nitrogen and phosphorus from human activities such as agriculture, reported Jacob Carstensen of Aarhus University in Denmark and colleagues.
 

03 Sep 2014

Sunken logs a delicacy for ocean bottom-feeders

Wood isn’t often on the menu for deep sea-dwelling critters, but for some species, there’s nothing like a tasty tree stump for dinner. Five years after leaving bundles of Acacia wood 3,200 meters deep at the bottom of Monterey Canyon off the central California coast, biologists retrieved the bundles with a remotely operated vehicle and found that some hosted diverse colonies of organisms.
 

29 Aug 2014

Ocean waves explain which La Niña events will linger

Cattle scavenging parched landscapes in search of tufts of crispy grass were the iconic image of the Texas drought in the winter of 2011. Record dry conditions inflicted nearly $8 billion in economic losses on the state’s agricultural sector before April showers brought a scant dose of relief. By fall, however, it became clear that warm, dry weather would return the following winter thanks to a persistent weather pattern in the tropical Pacific known as La Niña.

21 Jul 2014

Geomedia: Books: The earth system symphony

The planet is a symphony played by the orchestral sections of the atmosphere, hydrosphere, geosphere and biosphere, each of which includes many instruments. However, teasing out the myriad relationships in the concerto that is the earth system is daunting. Not only do the scales involved range from planetary to microscopic, but our observational records are also relatively short, and some features are inherently chaotic. Just understanding the basics of any one of the major components can take a lifetime.

17 Jun 2014

Staking a claim: Deep-sea mining nears fruition

At seafloor hydrothermal vents, high-temperature fluids precipitate deposits of minerals and metals beyond any prospector’s wildest dreams. Attempts to tap that mineral wealth are now underway, but questions remain about the environmental consequences of deep-sea mining.
 

27 May 2014

Scientists look wider and deeper to predict the next El Nino

Of all climate and weather phenomena, the El Niño Southern Oscillation (ENSO) is not only one of the most well known for its impact on world climate and human life, but is also one of the most puzzling to scientists. For this reason, researchers have begun to take into account a much more global area of climate data than previously considered with the hopes of predicting El Niño or La Niña conditions sooner than is currently possible.

17 Apr 2014

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