Tag Archives: nsf

Evolution of Earliest Horses Driven by Climate Change

*The hotter it gets, the smaller the animal?*

When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.

It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.

Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)

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U-M Divers Retrieve Prehistoric Wood from Lake Huron

ANN ARBOR, Mich.— Under the cold clear waters of Lake Huron, University of Michigan researchers have found a five-and-a-half foot-long, pole-shaped piece of wood that is 8,900 years old. The wood, which is tapered and beveled on one side in a way that looks deliberate, may provide important clues to a mysterious period in North American prehistory.

“This was the stage when humans gradually shifted from hunting large mammals like mastodon and caribou to fishing, gathering and agriculture,” said anthropologist John O’Shea. “But because most of the places in this area that prehistoric people lived are now under water, we don’t have good evidence of this important shift itself– just clues from before and after the change. (more…)

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Pine Island Glacier: A Scientific Quest in Antarctica to Determine What’s Causing Ice Loss

*Researchers study heat delivered by ocean currents to bottom side of glacier that releases more than 19 cubic miles of ice each year*

An international team of researchers, funded by the National Science Foundation (NSF) and NASA, will helicopter onto the Pine Island Glacier ice shelf, one of Antarctica’s most active, remote and harsh spots, in mid-December 2011–weather permitting.

The project’s mission is to determine how much heat ocean currents deliver to the underside of the Pine Island Glacier as it discharges into the sea. Quantifying this heat and understanding how much melting it causes is key to developing reliable models to predict glacier acceleration and therefore predict how much ice will be delivered from land into the ocean thus contributing to sea level rise. (more…)

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Geologist Finds Fiery Volcano Offers Glimpse into Land That Time Forgot

University of Hawai‘i at Mānoa geologist Kenneth Rubin is among the first scientists to witness exploding rock and molten lava from a deep sea volcano, seen during a 2009 expedition. He is co-author of a paper reporting that the eruption was near a tear in the Earth’s crust that is mimicking the birth of a subduction zone.

Scientists on the expedition collected boninite, a rare, chemically distinct lava that accompanies the formation of Earth’s subduction zones. (more…)

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West Nile Virus Transmission Linked with Land-Use Patterns and “Super-spreaders”

*Spread highest in urbanized and agricultural habitats*

After its initial appearance in New York in 1999, West Nile virus spread across the United States in just a few years and is now well established throughout North and South America.

Both the mosquitoes that transmit it and the birds that are important hosts for the virus are abundant in areas that have been modified by human activities.

As a result, transmission of West Nile virus is highest in urbanized and agricultural habitats. (more…)

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U.S. Rivers and Streams Saturated With Carbon

*Significant amount of carbon in land is leaking into streams and rivers, then to the atmosphere*

Rivers and streams in the United States are releasing substantially more carbon dioxide into the atmosphere than previously thought.

This according to researchers publishing their results in the current issue of the journal Nature Geoscience. (more…)

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Something Odd Is Happening With Namibia’s Weather

*Southwestern African country is no arid desert–this year*

Something’s up with the weather in Namibia, say geoscientists Kyle Nichols of Skidmore College in Saratoga Springs, N.Y., and Paul Bierman of the University of Vermont in Burlington, Vt.

Nichols and Bierman should know. They’re just back from the western mountains and coastal plain of this sparsely populated African country.

Usually, western Namibia is a dusty place where the stream beds are sand and the “lakes” are nothing more than flats of dried mud.

Not now. (more…)

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