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timothy oleson

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

Volcanic ash feed southern ocean plankton

Ash plumes from volcanoes in South America and elsewhere may spur large blooms of plankton in otherwise barren parts of the Southern Ocean, but maybe not for the reason scientists have suspected, according to a new study. Such blooms are of interest because they consume atmospheric carbon dioxide, although their overall effect on climate remains far from clear.
 

28 Aug 2014

The subcontinent's sturdy mammals

India is home to some hardy mammals, according to a new study in Proceedings of the National Academy of Sciences. Researchers reported that 20 of 21 mammalian taxa identified from fossils found in southern India have survived on the subcontinent over at least the last 100,000 years, with some lineages stretching back twice that long.
 

27 Aug 2014

Extra rib may be sign of mammoth decline

High rates of a congenital defect in woolly mammoths may offer evidence that inbreeding and environmental stress contributed to the animals’ demise during the Late Pleistocene, according to a new analysis of fossil mammoth neck bones.

26 Aug 2014

South American fossils offer revised view of Gondwana assembly

Fossils of a known age have been found for the first time in rocks in Brazil that, although long-studied, had previously eluded scientists’ attempts to pinpoint their age. The discovery of the marine animals dates the rocks to 550 million years ago, researchers say, offering important insights into the geological evolution and timing of the assembly of the former supercontinent Gondwana.
 

25 Aug 2014

Warm river water melted Arctic sea ice

In September 2012, the area of the Arctic Ocean covered by sea ice was the smallest on record since satellite monitoring began in 1979. Several factors are thought to have contributed to that summer’s diminished ice, including a large cyclone in August that brought warmer ocean waters into the area and broke up the ice and a longer-term trend of thinning and weakening sea ice. Now, researchers have found that at least one large burst of warm freshwater into the Arctic earlier in the summer probably played a role as well.
 

23 Aug 2014

Acid oceans followed Chicxulub impact

Within days after the massive Chicxulub impact that ended the Cretaceous Period 65.5 million years ago, a deluge of acid rain may have turned Earth’s ocean surfaces into suddenly inhospitable homes for a multitude of microorganisms, ultimately pushing them to extinction, according to a new study.
 

21 Aug 2014

Down to Earth With: Chris Strong

Being a weatherman is sometimes a thankless job, particularly when forecasts don’t pan out as expected. But the two-fold task of meteorologists — predicting the course and severity of impending weather events, and clearly communicating those predictions to a broad audience — is a vital one. This is especially true when you’re part of the group that so many people, including other forecasters, turn to as the primary source for weather information and insight: the National Weather Service (NWS).

18 Aug 2014

Mars Monthly

As Curiosity and Opportunity rove around Mars, the Mars Reconnaissance Orbiter (MRO), Mars Express and Mars Odyssey orbit above, and scientists on Earth study the Red Planet from afar, new findings are announced almost weekly. Here are a few of the latest updates.

31 Jul 2014

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