November 27, 2007, 10:44 PM CT

Where does stored nuclear waste go?

Millions of gallons of hazardous waste resulting from the nations nuclear weapons program lie in a remote location in southeastern Washington state called Hanford. Beneath this desert landscape about two million curies of radioactivity and hundreds of thousands of tons of chemicals are captured within the stratified vadose zone below which gives rise to complex subsurface flow paths. These paths create uncertainties about where the contaminants go and what happens to them. With the mighty Columbia River bordering much of the site, where these nuclear wastes migrate, their composition and how fast they are traveling are of vital importance to both people and the environment.

The recent issue of Vadose Zone Journal features a series of papers addressing the mysteries within the vadose zone beneath Hanford. The series outlines scientific work funded by the Department of Energy and carried out by researchers at Pacific Northwest National Laboratory and contributing associates with other national laboratories, universities and contractors.

The detailed series outlines how scientists have investigated Hanfords vadose zone to better understand the migration of these contaminants, ultimately reducing or stemming their flow toward the Columbia River, thereby protecting the river and the people living downstream. By studying the geologic, biologic, geochemical and hydrologic conditions at the Hanford site, the scientists seek to understand and manipulate the factors that control contaminants fate and transport......... Posted by: Tyler      Read more         Source

November 19, 2007, 8:36 PM CT

Tsunami-recording in the deep sea

Bremerhaven, November 15, 2007. In order to extend alert times and avoid false alarms, a new seafloor pressure recording system has been designed to detect tsunamis shortly after their development in the open ocean. The project is directed by researchers of the working group Marine Observation Systems at the Alfred Wegener Institute for Polar and Marine Research, part of the Helmholtz Association. Successful testing of the recording system off the Canary Islands in November 2007 means that a new mile stone for the development of the Indian Ocean Tsunami Early Warning System (GITEWS) has been reached.

The GITEWS project is supervised by the German National Research Centre for Geosciences (GFZ) in Postdam. Researchers of the Alfred Wegener Institute, in collaboration with companies Optimare and develogic, and with the Zentrum fr Marine Umweltwissenschaften (MARUM) and the University of Rhode Island, are in the process of developing part of the simulation component and the so-called pressure-based acoustically coupled tsunami detector (PACT) for real-time detection of sea level rises in the deep ocean.

The German tsunami early warning system is unique in that it processes a multitude of information as the basis for a comprehensive and accurate evaluation of every particular situation. Within just few minutes, measurements of the vibrations and horizontal seafloor movements off the coast of Indonesia provide a clear picture of the location and intensity of a seaquake, which, at the warning centre, facilitate the appropriate selection of a previously calculated tsunami propagation model. However, not every seafloor quake causes a tsunami. There is only one way to be clear about this and avoid nerve-wrecking and costly false alarms: we must measure sea level directly, says PACT-project leader Dr Olaf Boebel of the Alfred Wegener Institute......... Posted by: Tyler      Read more         Source

November 19, 2007, 8:20 PM CT

Understanding Smog Formation

Researchers at the U.S. Department of Energy's Brookhaven National Laboratory have developed a new tool for quantitatively measuring elusive atmospheric chemicals that play a key role in the formation of photochemical smog. Better measurements will improve scientists' understanding of the mechanisms of smog formation and their ability to select and predict the effectiveness of various mitigation strategies. The Brookhaven researchers have been issued a U.S. patent for their apparatus, which is available for licensing.

The device measures atmospheric hydroperoxyl radicals - short-lived, highly reactive intermediates involved in the formation of ozone, a component of photochemical smog - in the lowest layer of Earth's atmosphere. The levels of these radicals can indicate which of a variety of chemical pathways is predominant in converting basic starting ingredients - hydrocarbons, nitrogen oxides, and water vapor - into smog in the presence of sunlight.

"Understanding the relative importance of the various pathways can help you tailor your mitigation strategies," said Brookhaven atmospheric chemist Stephen Springston, one of the inventors. "For example, are you better off spending your money reducing hydrocarbon emissions or nitrogen oxide emissions?".

"Our measurements will help predict which strategy would be most successful for a particular set of atmospheric conditions - and make modifications to the strategy as those conditions change," said co-inventor Judy Lloyd of the State University of New York at Old Westbury, who holds a guest appointment at Brookhaven Lab......... Posted by: Tyler      Read more         Source

November 15, 2007, 10:07 PM CT

Earth's crust reveals inner workings of a tsunami factory

AUSTIN, TexasResearch announced this week by a team of U.S. and Japanese georesearchers may help explain why part of the seafloor near the southwest coast of Japan is especially good at generating devastating tsunamis, such as the 1944 Tonankai event, which killed at least 1,200 people. The findings will help researchers assess the risk of giant tsunamis in other regions of the world.

Georesearchers from The University of Texas at Austin and his colleagues used a commercial ship to collect three-dimensional seismic data that reveals the structure of Earths crust below a region of the Pacific seafloor known as the Nankai Trough. The resulting images are akin to ultrasounds of the human body.

The results, published this week in the journal Science, address a long standing mystery as to why earthquakes below some parts of the seafloor trigger large tsunamis while earthquakes in other regions do not.

The 3D seismic images allowed the scientists to reconstruct how layers of rock and sediment have cracked and shifted over time. They found two things that contribute to big tsunamis. First, they confirmed the existence of a major fault that runs from a region known to unleash earthquakes about 10 kilometers (6 miles) deep right up to the seafloor. When an earthquake happens, the fault allows it to reach up and move the seafloor up or down, carrying a column of water with it and setting up a series of tsunami waves that spread outward......... Posted by: Tyler      Read more         Source

November 13, 2007, 9:28 PM CT

Regional variation in warming from sun

A NASA satellite designed, built and controlled by the University of Colorado at Boulder is expected to help researchers resolve wide-ranging predictions about the coming solar cycle peak in 2012 and its influence on Earth's warming climate, as per the chief scientist on the project.

Senior Research Associate Tom Woods of CU-Boulder's Laboratory for Atmospheric and Space Physics said the brightening of the sun as it approaches its next solar cycle maximum will have regional climatic impacts on Earth. While some researchers predict the next solar cycle -- expected to start in 2008 -- will be significantly weaker than the present one, others are forecasting an increase of up to 40 percent in the sun's activity, said Woods.

Woods is the principal investigator on NASA's $88 million Solar Radiation and Climate Experiment, or SORCE, mission, launched in 2003 to study how and why variations in the sun affect Earth's atmosphere and climate. In August, NASA extended the SORCE mission through 2012. The extension provides roughly $18 million to LASP, which controls SORCE from campus by uploading commands and downloading data three times daily to the Space Technology Building in the CU Research Park.

Solar cycles, which span an average of 11 years, are driven by the amount and size of sunspots present on the sun's surface, which modulate brightness from the X-ray to infrared portion of the electromagnetic spectrum. The current solar cycle peaked in 2002......... Posted by: Tyler      Read more         Source

November 13, 2007, 9:21 PM CT

River Restoration Poorly Coordinated

The process of river restoration in the U.S. is uncoordinated at almost every level. Project scales are rarely associated with goals, and evaluation is rarely reported or used to assess whether these goals are achieved. A new study published in Restoration Ecology is the first attempt to systematically determine the motivations behind river restoration throughout the U.S., and to assess the ways in which projects are being reviewed.

Despite considerable optimism from restoration project managers, two-thirds of whom felt that their restorations had been "completely successful," the study finds that the process of river restoration is poorly coordinated. Project goals, design, implementation and evaluation are disconnected. Evaluations are uncommon and are rarely reported or used to assess whether goals have been met. The study also finds little coordination between separate projects, something that is essential for successfully addressing watershed degradation.

River restoration is a popular approach to watershed management in the U.S., where over one-third of all rivers are degraded due to alterations in the shape of river channels, chemistry of the waters and the timing and amount of water they receive. Each year more than $1 billion is spent on these projects......... Posted by: Tyler      Read more         Source

November 7, 2007, 4:54 AM CT

Climate Change Could Diminish Drinking Water

As sea levels rise, coastal communities could lose up to 50 percent more of their fresh water supplies than previously thought, as per a new study from Ohio State University.

Hydrologists here have simulated how saltwater will intrude into fresh water aquifers, given the sea level rise predicted by the Intergovernmental Panel on Climate Change (IPCC). The IPCC has concluded that within the next 100 years, sea level could rise as much as 23 inches, flooding coasts worldwide.

Researchers previously assumed that, as saltwater moved inland, it would penetrate underground only as far as it did above ground.

But this new research shows that when saltwater and fresh water meet, they mix in complex ways, depending on the texture of the sand along the coastline. In some cases, a zone of mixed, or brackish, water can extend 50 percent further inland underground than it does above ground.

Like saltwater, brackish water is not safe to drink because it causes dehydration. Water that contains less than 250 milligrams of salt per liter is considered fresh water and safe to drink.

Motomu Ibaraki, associate professor of earth sciences at Ohio State, led the study. Graduate student Jun Mizuno presented the results Tuesday, October 30, 2007, at the Geological Society of America meeting in Denver......... Posted by: Tyler      Read more         Source

October 29, 2007, 10:14 PM CT

Blue Mountain rocks related to Klamath

New evidence, based on mineral dating, suggests that rocks of the Blue Mountains, the oldest geological formation in Oregon, may have been derived from the Klamath and Sierra Nevada mountain chains, University of Oregon scientists report.

The findings, presented today (Oct. 29) at the annual meeting of the Geological Society of America, come from zircon grains in Triassic and Jurassic sedimentary rocks (dating from 144 million to 248 million years ago) from Blue Mountain basins in northeastern Oregon. The approximate ages of the zircons, based on isotropic dating, match the ages of rocks to the south in the Klamath Mountains, said Todd LaMaskin, a UO doctoral student in geological sciences.

Detrital zircon dating is a much-used technique that uses isotopes of uranium and lead from zircon grains found in sedimentary rocks, commonly sandstones. Such dating allows geologists to look back in time by billions of years.

"Zircons are very stable, can be weathered out of a rock, transported long distances and deposited in sedimentary basins," LaMaskin said. "We start with a block of sandstone, haul it out, crush it and mill it, and use various chemical and magnetic techniques to concentrate the zircons. We might start with 40 pounds of sandstone and end up with 100 to 200 zircons, all of which would fit on the head of a pin"......... Posted by: Tyler      Read more         Source

October 28, 2007, 4:22 PM CT

Agricultural Soil Erosion Is Not Adding to Global Warming

Agricultural soil erosion is not a source of carbon dioxide to the atmosphere, as per research published online today (October 25) in the journal Science. The study was carried out by an international team of scientists from UC Davis, the Catholic University of Leuven in Belgium, and the University of Exeter in the U.K.

Carbon emissions are of great concern worldwide because they, and other greenhouse gases, trap heat in the Earth's atmosphere and are a major cause of global climate change.

"There is still little known about how much carbon exactly is released, versus captured, by different processes in terrestrial ecosystems," said Johan Six, a professor of agroecology at UC Davis and one of the study's authors. "We urgently need to quantify this if we are to develop sensible and cost-effective measures to combat climate change".

In their new study, the scientists observed that erosion acts like a conveyor belt, excavating subsoil, passing it through surface soils and burying it in hollows downhill. During its journey, the soil absorbs carbon from plant material; when the soil is buried, so is the carbon.

Erosion, therefore, creates what can be described as a "sink" of atmospheric carbon.

The team improved prior estimates of the amount of carbon being sunk. Said lead author Kristof Van Oost of the Catholic University of Leuven, "Some academics have argued that soil erosion causes considerable emissions of carbon, and others that erosion is actually offsetting fossil-fuel emissions. Now, our research clearly shows that neither of these is the case"......... Posted by: Tyler      Read more         Source

October 28, 2007, 4:13 PM CT

Less Arctic ice means higher risks

The International Ice Charting Working Group predicts more marine transportation in the Arctic as sea ice continues to diminish and warns of "significant hazards to navigation," as per a statement released yesterday.

The statement was released during a five-day conference held at ESRIN, ESA's Earth Observation Centre in Frascati, Italy, in which operational ice experts from Europe and North America gathered to discuss the state of the polar regions.

"In September 2007, the Arctic sea ice reached the minimum extent - the lowest amount of ice recorded in the area annually - in the history of ice charting based on satellite, aircraft and surface observations, continuing a recent trend of diminishing sea ice that began in the 1980s and has accelerated. While there will still be natural inter-annual variability, the decline is likely to continue," the statement reads.

"The Arctic is already experiencing an increase in shipping, primarily for oil and gas development and tourism, and we can expect to see further increases as diminishing ice extent makes Arctic marine transportation more viable. The International Ice Charting Working Group (IICWG) cautions that sea ice and icebergs will continue to present significant hazards to navigation for the foreseeable future." ......... Posted by: Tyler      Read more         Source