Tag Archives: isotopes

Radiation Safety for Sunken-Ship Archaeology

Berkeley Lab researchers help scientists determine the radiation risk of exploring an underwater aircraft carrier.

About 42 miles southwest of San Francisco and 2,600 feet underwater sits the U.S.S. Independence, a bombed-out relic from World War II. The aircraft carrier was a target ship in atomic weapon tests at Bikini Atoll in the Marshall Islands after the war. Then, in 1951, it was loaded up with 55-gallon drums of low-level radioactive waste and scuttled just south of the Farallon National Wildlife Refuge off the California coast. (more…)

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Chemical tags in ear bones track Alaska’s Bristol Bay salmon

A chemical signature recorded on the ear bones of Chinook salmon from Alaska’s Bristol Bay region could tell scientists and resource managers where they are born and how they spend their first year of life. (more…)

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Lack of oxygen delayed the appearance of animals on Earth

Geologists are letting the air out of a nagging mystery about the development of animal life on Earth.

Scientists have long speculated as to why animal species didn’t flourish sooner, once sufficient oxygen covered the Earth’s surface. Animals began to prosper at the end of the Proterozoic period, about 800 million years ago — but what about the billion-year stretch before that, when most researchers think there also was plenty of oxygen? (more…)

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Ancient shark teeth give clues to future of Arctic climate change

A new study of sharks that lived in warm Arctic waters millions of years ago suggests that some shark species could handle the falling Arctic salinity that may come with rising temperatures.

The Arctic today is best known for its tundra and polar bear population, but roughly 38 to 53 million years ago during the Eocene epoch, the Arctic was like a huge temperate forest with brackish water, home to a variety of animal life, including ancestors of tapirs, hippo-like creatures, crocodiles and giant tortoises. Much of what is known about the region during this period comes from well-documented terrestrial deposits. Marine records have been harder to come by. (more…)

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Science Benefits From Diverse Landing Area of NASA Mars Rover

PASADENA, Calif. — NASA’s Curiosity rover is revealing a great deal about Mars, from long-ago processes in its interior to the current interaction between the Martian surface and atmosphere.

Examination of loose rocks, sand and dust has provided new understanding of the local and global processes on Mars. Analysis of observations and measurements by the rover’s science instruments during the first four months after the August 2012 landing are detailed in five reports in the Sept. 27 edition of the journal Science. (more…)

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How Mars’ atmosphere got so thin: New insights from Curiosity

ANN ARBOR — New findings from NASA’s Curiosity rover provide clues to how Mars lost its original atmosphere, which scientists believe was much thicker than the one left today.

“The beauty of these measurements lies in the fact that these are the first really high-precision measurements of the composition of Mars’ atmosphere,” said Sushil Atreya, professor of atmospheric, oceanic and space sciences at the University of Michigan. (more…)

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Building Blocks of Early Earth Survived Collision that Created Moon

COLLEGE PARK, Md. – Unexpected new findings by a University of Maryland team of geochemists show that some portions of the Earth’s mantle (the rocky layer between Earth’s metallic core and crust) formed when the planet was much smaller than it is now, and that some of this early-formed mantle survived Earth’s turbulent formation, including a collision with another planet-sized body that many scientists believe led to the creation of the Moon.

“It is believed that Earth grew to its current size by collisions of bodies of increasing size, over what may have been as much as tens of millions of years, yet our results suggest that some portions of the Earth formed within 10 to 20 million years of the creation of the Solar System and that parts of the planet created during this early stage of construction remained distinct within the mantle until at least 2.8 billion years ago.” says UMD Professor of Geology Richard Walker, who led the research team. (more…)

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