Tag Archives: ice age

Asian Monsoon Much Older Than Previously Thought

Scientists originally thought the climate pattern began 22-25 million years ago as a result of the uplift of the Tibetan Plateau and the Himalaya Mountains. But UA researchers say that’s not going back far enough.

The Asian monsoon already existed 40 million years ago during a period of high atmospheric carbon dioxide and warmer temperatures, reports an international research team led by a University of Arizona geoscientist. (more…)

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Dust in the wind drove iron fertilization during ice age

Researchers from Princeton University and the Swiss Federal Institute of Techonology in Zurich have confirmed that during the last ice age iron fertilization caused plankton to thrive in a region of the Southern Ocean.

The study published in Science confirms a longstanding hypothesis that wind-borne dust carried iron to the region of the globe north of Antarctica, driving plankton growth and eventually leading to the removal of carbon dioxide from the atmosphere. (more…)

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Undersea mountains provide crucial piece in climate prediction puzzle

A mystery in the ocean near Antarctica has been solved by researchers who have long puzzled over how deep and mid-depth ocean waters are mixed.

They found that sea water mixes dramatically as it rushes over undersea mountains in Drake Passage – the channel between the southern tip of South America and the Antarctic continent. Mixing of water layers in the oceans is crucial in regulating the Earth’s climate and ocean currents.

The research provides insight for climate models which until now have lacked the detailed information on ocean mixing needed to provide accurate long-term climate projections. The study was carried out by the University of Exeter, the University of East Anglia, the University of Southampton, the Woods Hole Oceanographic Institution, the British Antarctic Survey and the Scottish Association for Marine Science and is published in the journal Nature. (more…)

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Sea Floor Samples Help Explain Arid Southwest

Surface-dwelling algae adjust their biochemistry to surface temperatures. As they die and sink to the bottom, they build a sedimentary record of sea-surface temperature across millennia. Brown’s work on surface temperatures, coupled with work from Texas A&M on rainfall and weather patterns, has helped chart the wetter, lake-filled geological history of the currently arid American West.

During the last ice age, the landscape of the American West was very different. Where now there are deserts and salt flats in the Southwest and Great Basin regions, there once were giant lakes and wetlands. The Great Salt Lake, for example, is a tiny remnant of the prehistoric Lake Bonneville, which at one time covered almost 20,000 square miles. (more…)

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Ancient Story of Dartmoor Tors Has an Ice-Cold Twist

Ice extended further across the UK than previously thought and played a part in sculpting the rocky landscape of Dartmoor in South West England during the last Ice Age, according to new research which challenges previously held theories.

A study of the National Park area of Dartmoor, UK, shows for the first time that an ice cap and valley glaciers were present in its centre and that the naturally castellated stone outcrops, known as tors, were survivors.

The new research by the Universities of Durham and Exeter, and Stockton Riverside College, is published in the journal Quaternary Science Reviews.

Researchers, who carried out detailed observations on the ground and using aerial photography, say the evidence includes glacial features such as elongated rounded mounds or drumlins and hummocky landforms or moraines. Similar features may also exist in other upland areas of southwest England, indicating that small upland glaciers were regularly hosted in the region during periods of glaciation. (more…)

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English Literature Influenced Prize-Winning Paleontologist

For a short time in grade school, Kevin Boyce lived within two blocks of the La Brea tar pits in Los Angeles, a place where ice age mammal fossils had been discovered. Above his bed hung a poster of the Yale Peabody Museum’s famous Age of Reptiles mural. But it wasn’t a boyhood fascination with prehistoric life that influenced his interest in paleontology, but rather the medieval literary world of Chaucer that Boyce discovered in college.

“I didn’t think twice about fossils between the ages of 7 and 20,” said Boyce, associate professor in geophysical sciences. Even during his undergraduate studies in literature and biology at the California Institute of Technology in the early 1990s, the deep history of life on Earth was far from his mind. (more…)

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Ice-Age Reptile Extinctions Provide a Glimpse of Likely Responses to Human-Caused Climate Change

ANN ARBOR, Mich. — A wave of reptile extinctions on the Greek islands over the past 15,000 years may offer a preview of the way plants and animals will respond as the world rapidly warms due to human-caused climate change, according to a University of Michigan ecologist and his colleagues.

The Greek island extinctions also highlight the critical importance of preserving habitat corridors that will enable plants and animals to migrate in response to climate change, thereby maximizing their chances of survival.  (more…)

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