Antarctica
National Science Foundation (NSF) officials said today that iceberg B-15A is not blocking access to McMurdo Station, the U. S. logistics hub for much of the nation's research activity in Antarctica, contradicting widely circulated reports to the contrary.
Scientists have discovered evidence of microbial activity in a rock glacier high above tree line in the Rocky Mountains, a barren environment previously thought to be devoid of life. Found in an intermittent stream draining from the glacier, the evidence includes traces of dissolved organic material and high levels of nitrates, said Mark Williams, a scientist at Colorado University (CU)-Boulder. The high nitrate levels are believed to be a result of microbes metabolizing nitrogen within the glacier, said CU-Boulder graduate student Meredith Knauf.
New research presented at this week's annual meeting of the Geological Society of America shows that rising sea levels of as little as a half-meter per century have been sufficient to dramatically change the shoreline of the U.S. Gulf Coast within the past 10,000 years. The findings are significant because half-meter increases are within the moderate range of predictions for the Gulf Coast during this century.
Glaciers in West Antarctica are shrinking at a rate substantially higher than observed in the 1990s. They are losing 60 percent more ice into the Amundsen Sea than they accumulate from inland snowfall. The study was conducted by a science team from NASA, U.S. universities and from the Centro de Estudios Cient?ficos in Chile. It is based on satellite data and comprehensive measurements made in 2002 by a science team aboard a Chilean P-3 aircraft equipped with NASA sensors. Science Express published the findings today.
Glaciers in West Antarctica are shrinking at a rate substantially higher than observed in the 1990s. They are losing 60 percent more ice into the Amundsen Sea than they accumulate from inland snowfall. The study was conducted by a science team from NASA, U.S. universities and from the Centro de Estudios Cient?ficos in Chile. It is based on satellite data and comprehensive measurements made in 2002 by a science team aboard a Chilean P-3 aircraft equipped with NASA sensors. Science Express published the findings today.
A small unmanned observatory high on the Antarctic plateau provides the best star-viewing site on Earth, according to research published today in Nature. Australian researchers have shown than a ground-based telescope in Antarctica can take images almost as good as those from the Hubble Space Telescope, at a fraction of the cost. ''It represents arguably the most dramatic breakthrough in the potential for ground-based optical astronomy since the invention of the telescope,'' says University of New South Wales Associate Professor Michael Ashley, who co-authored the Nature paper.
Europeans who enjoy the Mediterranean's warm climate should thank Antarctica for their good fortune. Climate modelling by Australian scientists reveals that Antarctica's icy sea currents allow the balmy Gulf Stream to dictate warm weather conditions over much of the North Atlantic.
While rovers and orbiting spacecraft scour Mars searching for clues to its past, researchers have uncovered another piece of the red planet in the most inhospitable place on Earth -- Antarctica. The new specimen was found by a field party from the U.S. Antarctic Search for Meteorites program on Dec. 15, 2003, on an ice field in the Miller Range of the Transantarctic Mountains, roughly 750 kilometers from the South Pole. This 715.2-gram black rock, officially designated MIL 03346, was one of 1,358 meteorites collected by ANSMET during the 2003-2004 austral summer.
A paper published this week in the journal Science supports the hypothesis that heat transfer by ocean currents -- rather than global heating or cooling -- may have been responsible for the global temperature patterns associated with the abrupt climate changes seen in the North Atlantic during the past 80,000 years.
Authored by the University of Bremen's Frank Lamy and colleagues, the paper provides new evidence that Southern Hemisphere climate may not have changed in step with Northern Hemisphere climate. Though these new measurements of ocean surface temperature off Chile are consistent with information from Antarctic ice core samples, they still contradict measurements made on land in the Southern Hemisphere -- suggesting additional research will be needed to resolve the issue.
Human activity in the Industrial Age ? approximately the last 150 years ? has significantly increased atmospheric levels of methyl bromide, a gas known for harming the ozone layer in the Earth's stratosphere. A research team in California reached this conclusion after examining an ice core recovered from Antarctica. By studying air bubbles trapped in the core, the team was able to compare levels of methyl bromide in the atmosphere over the last three centuries. The team concluded that during the industrial era, the amount of global atmospheric methyl bromide in Southern Hemisphere air appears to have increased by 3.5 parts per trillion, or approximately 50 percent of the preindustrial level of the gas.
A balloon-shaped robot explorer that one day could search for water on other planets has survived some of the most trying conditions on planet Earth during a 70-kilometer (40-mile), wind-driven trek across Antarctica. The Tumbleweed Rover, which is being developed at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., left the National Science Foundation's Amundsen-Scott South Pole Station on Jan. 24, completing its roll across Antarctica's polar plateau roughly eight days later.
Scientists using cores drilled from the New Jersey coastal plain have found that ice sheets likely caused massive sea level change during the Late Cretaceous Period -an interval previously thought to be ice-free. The scientists assert that either ice sheets grew and decayed in that greenhouse world or our understanding of sea level mechanisms is fundamentally flawed.
Studies of the unique landscape in the Dry Valleys of Antarctica provide new insights into the origin of similar features on Mars and provide one line of evidence that suggests the Red Planet has recently experienced an ice age, according to a paper in this week?s issue of the journal Nature.
Data collected by a new seismic observatory at the National Science Foundation's Amundsen-Scott South Pole Station indicate that it is the quietest listening post on the planet for observing shudders produced by earthquakes around the world as they vibrate through the Earth. The South Pole Remote Earth Science Observatory is located eight kilometers from the South Pole and the new seismometers have been installed roughly 300 meters beneath the surface of the continental East Antarctic ice sheet in specially drilled boreholes.
A new study posits an alternative theory regarding why Antarctica suddenly became glaciated 34 million years ago. The study challenges previous thinking about why the ice sheet formed and holds ramifications for the next several hundred years as greenhouse gases continue to rise. "Scientists have long known that Antarctica was not always covered in a sheet of ice. Rather, the continent was once highly vegetated and populated with dinosaurs, with perhaps just a few Alpine glaciers and small ice caps in the continental interior," the study's lead researcher said.
