February 26, 2008, 7:54 PM CT

Supercomputer Unleashes Virtual 9.0 Megaquake

On January 26, 1700, at about 9 p.m. local time, the Juan de Fuca plate beneath the ocean in the Pacific Northwest suddenly moved, slipping some 60 feet eastward beneath the North American plate in a monster quake of approximately magnitude 9, setting in motion large tsunamis that struck the coast of North America and traveled to the shores of Japan.

Since then, the earth beneath the region - which includes the cities of Vancouver, Seattle and Portland -- has been relatively quiet. But researchers think that earthquakes with magnitudes greater than 8, so-called "megathrust events," occur along this fault on average every 400 to 500 years.

To help prepare for the next megathrust earthquake, a team of scientists led by seismologist Kim Olsen of San Diego State University (SDSU) used a supercomputer-powered "virtual earthquake" program to calculate for the first time realistic three-dimensional simulations that describe the possible impacts of megathrust quakes on the Pacific Northwest region. Also participating in the study were scientists from the San Diego Supercomputer Center at UC San Diego and the U.S. Geological Survey.

What the researchers learned from this simulation is not reassuring, as published in the Journal of Seismology, especially for residents of downtown Seattle......... Posted by: Tyler      Read more         Source

February 12, 2008, 9:51 PM CT

How river carbon impacts the Arctic Ocean

Arctic rivers transport huge quantities of dissolved organic carbon (DOC) to the Arctic Ocean. The prevailing paradigm regarding DOC in arctic rivers is that it is largely refractory, making it of little significance for the biogeochemistry of the Arctic Ocean. However, a recent study by R. M. Holmes of the Woods Hole Research Center and his colleagues at collaborating institutions challenges that assumption by showing that DOC in Alaskan arctic rivers is remarkably labile during the spring flood period when the majority of annual DOC flux occurs. The research was published February 9 in Geophysical Research Letters.

As per Dr. Holmes, Though only about 1% of global ocean volume, the Arctic Ocean receives almost 10% of global river discharge. As a consequence, organic carbon transported by arctic rivers has the potential to strongly impact the chemistry and biology of the Arctic Ocean.

The primary focus of the paper is the lability of dissolved organic carbon in Alaskan arctic rivers, or how available the DOC is for microbial decomposition. Because of logistical challenges, past studies have focused almost exclusively on the summer low-flow period, when numerous studies have shown arctic river DOC to be refractory. However, by timing their sampling to include the high-flow period just after the spring ice break, the authors observed that much of the DOC discharged by Alaskan rivers to the Arctic Ocean is labile. Consequently, riverine inputs of DOC to the Arctic Ocean may have a much larger influence on coastal ocean biogeochemistry than previously realized, and reconsideration of the role of terrigenous DOC on carbon, microbial, and food-web dynamics on the arctic shelf is warranted......... Posted by: Tyler      Read more         Source

February 12, 2008, 9:38 PM CT

Lake Mead Could Be Dry by 2021

There is a 50 percent chance Lake Mead, a key source of water for millions of people in the southwestern United States, will be dry by 2021 if climate changes as expected and future water usage is not curtailed, as per a pair of scientists at Scripps Institution of Oceanography, UC San Diego.

Without Lake Mead and neighboring Lake Powell, the Colorado River system has no buffer to sustain the population of the Southwest through an uncommonly dry year, or worse, a sustained drought. In such an event, water deliveries would become highly unstable and variable, said research marine physicist Tim Barnett and climate scientist David Pierce.

Barnett and Pierce concluded that human demand, natural forces like evaporation, and human-induced climate change are creating a net deficit of nearly 1 million acre-feet of water per year from the Colorado River system that includes Lake Mead and Lake Powell. This amount of water can supply roughly 8 million people. Their analysis of Federal Bureau of Reclamation records of past water demand and calculations of scheduled water allocations and climate conditions indicate that the system could run dry even if mitigation measures now being proposed are implemented.

The paper, "When will Lake Mead go dry?," has been accepted for publication in the peer-evaluated journal Water Resources Research, published by the American Geophysical Union, and is accessible via the AGU's website (see instructions below)......... Posted by: Tyler      Read more         Source

Tue, 12 Feb 2008 23:41:18 GMT

Eco cleaning products in your cupboard

If you''ve been gradually going green in your house, buying eco-friendly products as they become more available in supermarkets, you might not be aware that there are common household products you probably already have in your kitchen that can do most cleaning jobs: baking soda, salt, lemons, Castile soap, and white distilled vinegar (was there ever a product more versatile than baking soda?).

Read more at Revolution Health. Posted by: Sarah      Read more     Source

February 11, 2008, 8:09 PM CT

New Greenland Ice And Climate Change Models

A comprehensive new study authored by University at Buffalo researchers and their colleagues for the first time documents in detail the dynamics of parts of Greenland's ice sheet, important data that have long been missing from the ice sheet models on which projections about sea level rise and global warming are based.

The research, published online this month in the Journal of Glaciology, also demonstrates how remote sensing and digital imaging techniques can produce rich datasets without field data in some cases.

Traditionally, ice sheet models are very simplified, as per Beata Csatho, Ph.D., assistant professor of geology in the UB College of Arts and Sciences and lead author of the paper.

"Ice sheet models commonly don't include all the complexity of ice dynamics that can happen in nature," said Csatho. "This research will give ice sheet modelers more precise, more detailed data".

The implications of these richer datasets may be dramatic, Csatho said, particularly as they impact climate projections and sea-level rise estimates, such as those made by the United Nations Intergovernmental Panel on Climate Change (IPCC).

"If current climate models from the IPCC included data from ice dynamics in Greenland, the sea level rise estimated during this century could be twice as high as what they are currently projecting," she said......... Posted by: Tyler      Read more         Source

February 10, 2008, 10:09 PM CT

Studying rivers for clues to global carbon cycle

In the science world, in the media, and recently, in our daily lives, the debate continues over how carbon in the atmosphere is affecting global climate change. Studying just how carbon cycles throughout the Earth is an enormous challenge, but one Northwestern University professor is doing his part by studying one important segment -- rivers.

Aaron Packman, associate professor of civil and environmental engineering in the McCormick School of Engineering and Applied Science, is collaborating with ecologists and microbiologists from around the world to study how organic carbon is processed in rivers.

Packman, who specializes in studying how particles and sediment move around in rivers, is co-author of a paper on the topic published online in the journal Nature Geoscience.

The paper evaluates our current understanding of carbon dynamics in rivers and reaches two important conclusions: it argues that carbon processing in rivers is a bigger component of global carbon cycling than people previously thought, and it lays out a framework for how researchers should go about assessing those processes.

Much more is known about carbon cycling in the atmosphere and oceans than in rivers. Evaluating large-scale material cycling in a river provides a challenge -- everything is constantly moving, and a lot of it moves in floods. As a result, much of what we know about carbon processing in rivers is based on what flows into the ocean......... Posted by: Tyler      Read more         Source

February 4, 2008, 9:52 PM CT

Geotimes explores oil around the world

With oil hovering around $90 a barrel, Geotimes magazine examines emerging trends and issues in several obvious, and some not-so-obvious locations, in this months cover story Oil Around the World.

Land disputes, foreign sanctions, terrorism, war and economics play into the exploration and recovery of the worlds oil and natural gas reserves. Be it Libya, Iraq or Norway, the South China Sea or India, a number of of the issues are the same, leading to complications that often keep investors away from vast oil and natural gas reserves.

Land disputes rule the future of oil and gas exploration in a number of parts of the world. Uncertainty about the boundary between Norway and Russia in the Barents Sea is an obstacle to the development of vast oil and gas resources. Likewise, Asian countries continue to dispute areas of the South China Sea, locking away the possible oil and gas resources from the global economy. Yet, the economic possibilities are bringing countries together in cooperative seismic studies. Will this yield the potential for international agreement and investment?

Along with China, the growth in India has been fingered as one of the causes of the spike in oil prices. Though not historically a major oil producer, Indias heritage and geology may yield some future surprises......... Posted by: Tyler      Read more         Source

January 29, 2008, 9:19 PM CT

Agriculture is changing the chemistry of the Mississippi

Midwestern farming has introduced the equivalent of five Connecticut Rivers into the Mississippi River over the past 50 years and is adding more carbon dioxide annually into its waters, as per a research studypublished in Nature by scientists at Yale and Louisiana State universities.

Its like the discovery of a new large river being piped out of the corn belt, said Pete Raymond, lead author of the study and associate professor of ecosystem ecology at the Yale School of Forestry & Environmental Studies. Agricultural practices have significantly changed the hydrology and chemistry of the Mississippi River.

The scientists tracked changes in the levels of water and bicarbonate, which forms when carbon dioxide in soil water dissolves rock minerals. Bicarbonate plays an important, long-term role in absorbing atmospheric carbon dioxide, a greenhouse gas. Oceans then absorb the excess carbon dioxide and become more acidic in the process. Ocean acidification makes it more difficult for organisms to form hard shells in coral reefs, said R. Eugene Turner, a co-author of the study and a professor at the Coastal Ecology Institute at Louisiana State University.

The scientists concluded that farming practices, such as liming, changes in tile drainage and crop type and rotation, are responsible for the majority of the increase in water and carbon dioxide in the Mississippi River, which is North Americas largest river......... Posted by: Tyler      Read more         Source

January 28, 2008, 10:42 PM CT

Baffin Island ice caps shrink by 50 percent since 1950s

A new University of Colorado at Boulder study has shown that ice caps on the northern plateau of Baffin Island in the Canadian Arctic have shrunk by more than 50 percent in the last half century as a result of warming, and are expected to disappear by the middle of the century.

Radiocarbon dating of dead plant material emerging from beneath the receding ice margins show the Baffin Island ice caps are now smaller in area than at any time in at least the last 1,600 years, said geological sciences Professor Gifford Miller of CU-Boulder's Institute of Arctic and Alpine Research. "Even with no additional warming, our study indicates these ice caps will be gone in 50 years or less," he said.

The study also showed two distinct bursts of Baffin Island ice-cap growth commencing about 1280 A.D. and 1450 A.D., each coinciding with ice-core records of increases in stratospheric aerosols tied to major tropical volcanic eruptions, Miller said. The unexpected findings "provide tantalizing evidence that the eruptions were the trigger for the Little Ice Age," a period of Northern Hemisphere cooling that lasted from roughly 1250 to 1850, he said.

A paper on the subject was published online in Geophysical Research Letters and featured in the Jan. 28 edition of the American Geophysical Union journal highlights. Authors on the study included Miller, graduate students Rebecca Anderson and Stephen DeVogel of INSTAAR, Jason Briner of the State University of New York at Buffalo and Nathaniel Lifton of the University of Arizona......... Posted by: Tyler      Read more         Source

January 28, 2008, 10:17 PM CT

Less fish out, means more nitrogen in

A Canada-U.S. research team has observed that commercial fisheries play an unexpected role in the decline of water quality in coastal waters. In the latest issue of Nature Geoscience, Roxane Maranger and Nina Caraco explain that the collapse of the fisheries from decades of over fishing has played a significant role in disturbing the balance between nitrogen entering and leaving costal water systems.

The study, the first to examine the worlds 58 coatal regions, shows how failing to maintain ecosystems in a sustainable manner has wide-ranging consequences. Using data provided by the United Nations, Maranger and Caraco observed that commercial fishing has played an important, yet declining, role in removing man-made nitrogen from coastal waters.

Fish accumulate nitrogen as biomass, and when humans move fish from the ocean to the table through commercial fisheries, they are returning part of this terrestrial nitrogen generated by humans back to the land, said Maranger, a biology professor at the Universit de Montral (Canada).

Caraco, an aquatic biogeochemist at the Cary Institue of Ecosystem Studies (Millbrook, New York, U.S.) notes: While nitrogen is essential to plant and animal life in oceans, human export of nitrogen from land to ocean has resulted in exploding nitrogen levels in coastal waters over the past century. Nitrogen-rich fertilizer thats applied to farmland eventually makes its way into coastal waters via a network of streams and rivers. Fertilizer run-off is a significant source of nitrogen pollution to a number of coastal regions around the world......... Posted by: Tyler      Read more         Source