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Thawing Permafrost 50 Million Years Ago Led To Warm Global Events, Says New Study

By Guest PostApril 7, 2012EnvironmentAntarctica, arctic permafrost, carbon, climate, climatic threshold, CO2, earth, eccentric orbits, ecosystem, Environment, floor sediment, fossil fuel, frozen-soil, greenhouse gas levels, italy, kevin schaefer, methane gas, ocean, orbit, organic matter, paleocene eocene, permafrost, permafrost thaw, petm, rob deconto, soil, source, thermal maximum, university of urbino

A new study led by the University of Massachusetts Amherst and involving the University of Colorado Boulder proposes a simple new mechanism to explain the source of carbon that fed a series of extreme warming events on Earth about 50 million years ago called the Paleocene-Eocene Thermal Maximum, or PETM, as well as a sequence of similar, smaller warming events afterward.

“The standard hypothesis has been that the source of carbon was in the ocean in the form of frozen methane gas in ocean-floor sediments,” said lead study author Rob DeConto of the University of Massachusetts Amherst. “We are instead ascribing the carbon source to the continents in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws.” (more…)

12-Mile-High Martian Dust Devil Caught in Act

By Guest PostApril 6, 2012Scienceamazonis planitia, dust devil, earth, hirise camera, mars reconnaissance orbiter, martian dust devil, martian surface, meteorite impact, NASA, northern mars, northern summer solstice, plume, red planet, tucson, university of arizona

A Martian dust devil roughly 12 miles high (20 kilometers) was captured whirling its way along the Amazonis Planitia region of Northern Mars on March 14. It was imaged by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Despite its height, the plume is little more than three-quarters of a football field wide (70 yards, or 70 meters).

Dust devils occur on Earth as well as on Mars. They are spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to rotate, if conditions are just right. (more…)

New Understanding of Earth’s Mantle Beneath The Pacific Ocean

By Guest PostMarch 24, 2012Scienceasthenosphere, boundary, carnegie, crust, earth, evolution, factors, gutenberg discontinuity, lab, lithosphere, lithosphere asthenosphere boundary, mineral, molten rock, nick schmerr, pacific ocean basin, planet, plate tectonics

Washington, D.C. — Scientists have long speculated about why there is a large change in the strength of rocks that lie at the boundary between two layers immediately under Earth’s crust: the lithosphere and underlying asthenosphere. Understanding this boundary is central to our knowledge of plate tectonics and thus the formation and evolution of our planet as we know it today. A new technique for observing this transition, particularly in the portion of Earth’s mantle that lies beneath the Pacific Ocean basin, has led Carnegie and NASA Goddard scientist Nick Schmerr to new insight on the origins of the lithosphere and asthenosphere. His work is published March 23 in Science.

The lithosphere-asthenosphere boundary, or LAB, represents the transition from hot, convecting mantle asthenosphere to overlying cold and rigid lithosphere. The oceanic lithosphere thickens as it cools over time, and eventually sinks back into the mantle at Earth’s so-called subduction zones. (more…)

Study of Patagonian Glacier’s Rise and Fall Adds to Understanding of Global Climate Change

By Guest PostMarch 24, 2012Environment17th century, andes, antonio de vea, chilean glacier, climate, climate change, climate system, earth, fernando torrejon, fluctuation, glacial environment, glacial melt, glacier, glacier fluctuation, glaciomarine sediment, global temperature, golfo elefantes, gualas glacier, holocene glacier, icebreaker, marine environment, nathaniel b palmer, neoglacial fluctuation, northern patagonian icefield, past temperature, patagonia, patagonias fjords, rainfall data, san rafael, sebastien bertrand, sediment record, spanish explorers, university of ghent, voyages, whoi

Glaciers play a vital role in Earth’s climate system, and it’s critical to understand what contributes to their fluctuation.

Increased global temperatures are frequently viewed as the cause of glacial melt, but a new study of Patagonia’s Gualas Glacier highlights the role of precipitation in the glacier’s fluctuation. The study, conducted by Sébastien Bertrand of the Woods Hole Oceanographic Institution (WHOI) and his colleagues, reconstructs a 5,400 year-record of the region’s glacial environment and climate, comparing past temperature and rainfall data with sediment records of glacier fluctuations and the historical observations of early Spanish explorers. (more…)

Global Sea Level Likely to Rise as Much as 70 Feet in Future Generations

By Guest PostMarch 22, 2012Environmentandrew kulpecz, atmosphere, atmospheric temperature, core, degrees celsius, earth, east antarctic, eniwetok atoll, future generation, global warming, greenland, humankind, ice sheets, james browning, james wright, kenneth miller, michelle kominz, mountain glaciers, new zealand, pacific ocean, partial melting, richard lane, rise of sea level, rock, Rutgers University, sea level, sindia sosdian, virginia, west antarctic, yair rosenthal

*Scientists looked back in time–in the geologic record–to see the future*

Even if humankind manages to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit)–as the Intergovernmental Panel on Climate Change recommends–future generations will likely have to deal with a completely different world.

One with sea levels 40 to 70 feet higher than at present, according to research results published this week in the journal Geology. (more…)

Scholars Say Global Governance Overhaul Needed For Earth’s Sustainability

By Guest PostMarch 19, 2012Environmentearth, environmental change, environmental institution, environmental scholar, frank biermann, geo engineering, global governance, model, Nanotechnology, reform, rio de janeiro, societal change, steven bernstein, subsystem, sustainable development, synthetic biology, un, united nations

A group of the world’s leading environmental scholars are sounding the alarm that human societies need to transform their national and international environmental institutions into a more coherent and robust planetary stewardship model to steer away from rapid and irreversible changes to the Earth’s subsystems.

University of Toronto political scientist Steven Bernstein is one of the authors of a paper which appears in Science on March 16, 2012. (more…)

NASA Mars Orbiter Catches Twister in Action

By Guest PostMarch 11, 2012Scienceamazonis planitia, dust devil, earth, hirise, mars, mars reconnaissance orbiter, martian year, NASA, sun rays, tornado, university of arizona, whirlwind

An afternoon whirlwind on Mars lofts a twisting column of dust more than half a mile (800 meters) high in an image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter.

HiRISE captured the image on Feb. 16, 2012, while the orbiter passed over the Amazonis Planitia region of northern Mars. In the area observed, paths of many previous whirlwinds, or dust devils, are visible as streaks on the dusty surface. (more…)

When Continents Collide: A New Twist To a 50 Million-Year-Old Tale

By Guest PostMarch 1, 2012Scienceearth, earthquakes, eurasia, fifty million years, geological activity, geological history, geology, geomorphologist, geophysicist, highest mountain, himalaya mountains, India, indian plate, indian sub continent, jim erickson, marin clark, mountain building episode, northern india, northern tibet, plate boundaries, plate tectonics, post collisional motion, the himalaya, theory, tibet, tibetan plateau, university of michigan, volcanoes

ANN ARBOR, Mich.— Fifty million years ago, India slammed into Eurasia, a collision that gave rise to the tallest landforms on the planet, the Himalaya Mountains and the Tibetan Plateau.

India and Eurasia continue to converge today, though at an ever-slowing pace. University of Michigan geomorphologist and geophysicist Marin Clark wanted to know when this motion will end and why. She conducted a study that led to surprising findings that could add a new wrinkle to the well-established theory of plate tectonics – the dominant, unifying theory of geology. (more…)

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