Delaware Geological Survey carbon-dates groundwater found to be thousands of years old
A drop of rain that falls near Middletown, Del., may take as long as 14,000 years to seep through the earth and trickle underground into a well several miles away, according to new research by the Delaware Geological Survey (DGS).
Scientists used radiocarbon-dating techniques to determine the age of groundwater from sites in southern New Castle and Kent counties. (more…)
Although humans and woolly mammoths co-existed for millennia, the shaggy giants disappeared from the globe between 4,000 and 10,000 years ago, and scientists couldn’t explain until recently exactly how the Flintstonian behemoths went extinct.
In a paper published June 12 in the journal Nature Communications, UCLA researchers and colleagues reveal that not long after the last ice age, the last woolly mammoths succumbed to a lethal combination of climate warming, encroaching humans and habitat change — the same threats facing many species today. (more…)
ANN ARBOR, Mich.— After the last ice age peaked about 18,000 years ago, levels of atmospheric carbon dioxide rose about 30 percent. Scientists believe that the additional carbon dioxide—a heat-trapping greenhouse gas—played a key role in warming the planet and melting the continental ice sheets. They have long hypothesized that the source of the gas was the deep ocean.
But a new study by a University of Michigan paleoclimatologist and two colleagues suggests that the deep ocean was not an important source of carbon during glacial times. The finding will force researchers to reassess their ideas about the fundamental mechanisms that regulate atmospheric carbon dioxide over long time scales. (more…)
GAINESVILLE, Fla. — After a 10,000-year absence, wildfires have returned to the Arctic tundra, and a University of Florida study shows that their impact could extend far beyond the areas blackened by flames.
In a study published in the July 28 issue of the journal Nature, UF ecologist Michelle Mack and a team of scientists including fellow UF ecologist Ted Schuur quantified the amount of soil-bound carbon released into the atmosphere in the 2007 Anaktuvuk River fire, which covered more than 400 square miles on the North Slope of Alaska’s Brooks Range. The 2.1 million metric tons of carbon released in the fire — roughly twice the amount of greenhouse gases put out by the city of Miami in a year — is significant enough to suggest that Arctic fires could impact the global climate, said Mack, an associate professor of ecosystem ecology in UF’s department of biology. (more…)
*Rate is greater now than at any time during past 2,100 years*
The rate of sea level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years–and has shown a consistent link between changes in global mean surface temperature and sea level.
The findings are published this week in the journal Proceedings of the National Academy of Sciences (PNAS). (more…)
*Statue at temple in Peru helps us understand ancient culture, myths*
COLUMBIA, Mo. – A University of Missouri archeologist has found a 4,000-year-old statue in Peru that gives new insight into an ancient agricultural society.
Robert Benfer, a professor emeritus of anthropology, said the mud plaster bust – a bust of a figure blowing a trumpet and another mask-like image flanked by foxes – was found at the “Buena Vista” site in the Andes Mountains, about 30 miles north of Lima, Peru. Radiocarbon dating indicates the bust was created around 2,000 B.C, making it the oldest 3-D statue found in the Americas. (more…)
The Chaiten volcano in southern Chile sprung to life for the first time in thousands of years. The powerful eruption sent ash more than 20 km into the sky and caused a poor visibility in the area. After drifting across Argentina (the southern most country), the plume of ash dissipated over the Atlantic.