Researchers have modified the European Incoherent Scatter Svalbard radar to potentially provide detailed information of even a single event in the polar ionosphere. Oksavik et al. demonstrate a new observation mode for the EISCAT instrument with the potential for monitoring small-scale flow variations in the Earth-space boundary. The authors used the technique to provide high-resolution data for the flow patterns surrounding a single poleward-moving auroral form (PMAF) event, a phenomenon ass
Including the atmospheric effects from volcanic eruptions in general circulation models may be the most important factor in improving the accuracy of long-term climate simulations. Vyushin et al. analyzed general circulation model estimates for the 20th century climate and found that volcanic eruptions, rather than the manmade effects from increasing greenhouse gas and aerosol levels, are the most significant factor in determining long-range correlations of surface air temperature. The author
An analysis of total solar irradiance data has allowed researchers to make the first detections of a solar flare from radiation-sensing satellites. Woods et al. report that total solar irradiance dropped by an unprecedented 0.34 percent during the strong solar storm in October-November 2003, because of large, dark sunspots observed by two NASA satellite missions. They also present data showing marked short-term solar radiation increases during one of the strongest X-class events seen during t
A web of faults links the San Andreas Fault over a discontinuous 80-kilometer [50 mile] region in southern California. Carena et al. analyzed a gap in the famous fault line that runs from the Mojave Desert to the Coachella Valley and suggest that a network of seismically active faults likely connects the two strands of the 1,200-kilometer [750-mile] San Andreas Fault.
The researchers examined the three-dimensional geometry of the fault system in the complex region, reaching nearly 20 kilom
Part of the magnetic dust observed in Greenland ice cores may come from extraterrestrial sources, although most of the surface magnetism of ice also comes from iron-rich particles deposited by airborne dust. Lanci et al. used magnetic testing techniques on ice cores from central Greenland to trace the iron oxide content and total dust concentration in polar sources.
They suggest that measuring the magnetic strength of dust deposited on the icy surface can provide researchers an improved me
Researchers propose that an observed rise in the ice-melting rate during the summer and an extension of the melting periods through October in the Alps may be caused by global warming. Vincent et al. analyzed more than 50 years of data showing the annual mass balance changes for two glaciers in the Alps and report anomalous ice melting that was likely caused by climate change. The authors note an ice reduction of nearly half a centimeter [two-tenths of an inch] per day over the widely space
A worst-case scenario of climate change from the possible future release of submerged methane hydrates predicts catastrophic warming in the atmosphere and rising sea level similar to conditions that preceded the last ice age. Renssen et al. simulated the climate response from a massive release of methane from gas hydrates in the oceans, using a three-dimensional model to estimate the changes to the atmosphere-sea ice-ocean system over 2,500 years. Although the researchers do not speculate on
A new study examines the factors that would enable researchers to create a Martian version of the Global Positioning System widely used on Earth. Mendillo et al. investigated the planet’s ionospheric characteristics with radio signal data taken from the Mars Global Surveyor spacecraft and analyzed how local time, latitude, and solar cycle patterns would affect Mars’ electron content and contribute to errors in estimating exact locations on the planet’s surface. They note that,
Though the catastrophe that destroyed the dinosaurs’ world may have begun with blazing fire, it probably ended with icy darkness, according to a Purdue University research group.
By analyzing fossil records, a team of scientists including Purdue’s Matthew Huber has found evidence that the Earth underwent a sudden cooling 65 million years ago that may have taken millennia to abate completely. The fossil rock samples, taken from a well-known archaeological site in Tunisia, show that
The National Center for Atmospheric Research (NCAR) in Boulder, Colo., is unveiling a powerful new version of a supercomputer-based system to model Earth’s climate and to project global temperature rise in coming decades. Scientists will contribute results to the next assessment by the Intergovernmental Panel on Climate Change (IPCC), an international research body that advises policymakers on the likely impacts of climate change. The system, known as the Community Climate System Model, version
New findings suggest that surface geometry determines volcanic activity
What causes the peaks and valleys of the world’s great mountains? For continental ranges like the Appalachians or the Northwest’s Cascades, the geological picture is clearer. Continents crash or volcanoes erupt, then glaciers erode away. Yet scientists are still puzzling out what makes the highs high and the lows low for the planet’s largest mountain chain, the 55,000-mile-long Mid-Ocean Ridge.
This we
When the Nisqually earthquake struck western Washington in 2001, brick chimneys in parts of West Seattle and Bremerton were left looking like so much straw after the Big Bad Wolf had gone huffing and puffing through. Hundreds of brick chimneys at the north end of West Seattle and north of Puget Sound Naval Shipyard in Bremerton were seriously damaged or toppled by the magnitude 6.7 temblor.
New research suggests the main culprit might have been the Seattle fault, even though the earthquake
There are elaborate hieroglyphs, burial objects and other clues.
But the recent application of a geological technique to an archaeological problem may offer a unique tool for gleaning seemingly unknowable facts about the ancient Maya – based only on excavated bones and teeth.
University of Florida geology Professor David Hodell and Associate Professor Mark Brenner did an elaborate review of the technique, which combines elements of geology, anthropology and forensic science,
The University of Colorado at Boulder’s Laboratory for Atmospheric and Space Physics has been selected by NASA to build two of the three instruments for a satellite that will launch in 2006 to study noctilucent clouds, the shiny, silvery-blue polar mesospheric clouds that form about 50 miles over Earth’s polar regions each summer.
The Aeronomy of Ice in the Mesosphere mission, or AIM, will receive $100 million in NASA funding for development and flight of the satellite. CU’s LASP will recei
On 2 May 2004, the High-Resolution Stereo Camera (HRSC) on board the ESA Mars Express spacecraft obtained images from the central area of the Mars canyon called Valles Marineris.
The images were taken at a resolution of approximately 16 metres per pixel. The displayed region is located at the southern rim of the Melas Chasma at Mars latitude 12°S and Mars longitude 285°E. The images were taken on orbit 360 of Mars Express.
This region shows several clues to the morphological and
Scientists have discovered a striking similarity between certain ocean currents on Earth and the bands that characterize the surface of large, gaseous planets like Jupiter. Boris Galperin of the University of South Florida’s College of Marine Science in Saint Petersburg and colleagues in the United States, Israel, and Japan report their findings later this month in Geophysical Research Letters, published by the American Geophysical Union. “The banded structure of Jupiter has long been a
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