Ward Hunt Ice Shelf, Largest In Northern Hemisphere, Has Fractured Into Three Main Pieces

Source:

http://www.sciencedaily.com/releases/2008/04/080415205350.htm

ScienceDaily (Apr. 16, 2008) — A team of scientists including polar expert Dr. Derek Mueller from Trent University and Canadian Rangers have discovered that the largest ice shelf in the Northern Hemisphere has fractured into three main pieces.
During their sovereignty patrol across the northernmost parts of Canada over the last two weeks, they visited a new 18 kilometre-long network of cracks running from the southern edge of the Ward Hunt Ice Shelf to the Arctic Ocean. This accompanies a large central fracture that was first detected in 2002, and raises the concern that the remaining ice shelf will disintegrate within the next few years.
Evidence of these cracks first came from Radarsat satellite images in February. Confirmation came from Canadian Rangers, partnering with International Polar Year scientists during Operation NUNALIVUT 08, a Canadian Forces High Arctic sovereignty patrol. Rangers mapped the extent of the fissures and monitored melt rates for Quttinirpaaq National Park, which encompasses the ice shelf.
The patrol scientists also found that the nearby Petersen Ice Shelf lost over a third of its surface area in the past three years. This ice shelf calved following the break-up of landfast sea ice in the summer of 2005 and 2007, which had protected it from the open ocean.
“Canadian ice shelves have undergone substantial changes in the past six years, starting with the first break-up event on the Ward Hunt Ice Shelf, and the loss of the Ayles Ice Shelf,” said Dr. Luke Copland of the University of Ottawa. “These latest break-ups we are seeing have come after decades of warming and are irreversible,” said Dr. Derek Mueller of Trent University.
Only five large ice shelves remain in Arctic Canada, covering less than a tenth of the area than they did a century ago.
Derek Mueller holds Trent's Roberta Bondar Fellowship in Northern and Polar Studies.
Adapted from materials provided by Trent University.

Fausto Intilla - www.oloscience.com

Better Understanding Of Hurricane Trajectories Learned From Patterns On Soap Bubbles

Source:

http://www.sciencedaily.com/releases/2008/04/080414214800.htm

ScienceDaily (Apr. 15, 2008) — Researchers at the Centre de Physique Moléculaire Optique et Hertzienne (CPMOH) (CNRS/Université Bordeaux (1) and the Université de la Réunion(1) have discovered that vortices created in soap bubbles behave like real cyclones and hurricanes in the atmosphere. Soap bubbles have enabled the researchers to characterize for the first time the random factor that governs the movement and paths of vortices. These results, published in the journal Physical Review Letters, could lead to a better understanding of such increasingly common and often devastating atmospheric phenomena.
A soap bubble is an ideal model for studying the atmosphere because it has analogous physical properties and, like the atmosphere, it is composed of a very thin film in relation to its diameter(2). In this experiment, the researchers created a half soap bubble that they heated at the “equator” and then cooled at the “poles”, thereby creating a single large vortex, similar to a hurricane, in the wall of the bubble. The researchers studied the movement of this vortex, which fluctuates in a random manner. This is characterized by a law known as a superdiffusive law(3), well known to physicists, but which had not until then been observed in the case of single vortices in a turbulent environment.
The disconcerting resemblance between vortices on soap bubbles and cyclones led the researchers to study their similarities. By analyzing in detail the trajectories of certain recent hurricanes such as Ivan, Jane, Nicholas, etc., the researchers measured the random factor that is always present in the movement of hurricanes. They then demonstrated the remarkable similarity of these fluctuations with those that characterize the disordered movement of the vortices that they created on soap bubbles.(4)
Taking this random factor into account in predicting the trajectory of hurricanes will be useful in anticipating the probability of impact on a given site or locality. Although the mean trajectory of hurricanes (without any fluctuations) is beginning to be well simulated by meteorologists, this random factor has, until now, been poorly understood. This discovery highlights a universality in the statistics of trajectory fluctuations and should make it possible in the future to better predict the behavior of hurricanes and anticipate the risks.
Notes :
1) Laboratoire de Génie Industriel.
2) The skin or film of soap is only several microns thick whereas the diameter of the bubble is around ten centimeters.
3) Law corresponding to a “Levy flight” random type movement, in other words a type of random walk dominated by several jumps of limited number but of large amplitude.
4) With a similar superdiffusive law.
Journal reference: Thermal convection and emergence of isolated vortices in soap bubbles, F. Seychelles, Y. Amarouchene, M. Bessafi*, and H. Kellay Université Bordeaux 1, CPMOH UMR 5798 du CNRS and * Université de la Réunion, Lab. de Génie Industriel. Physical Review Letters. April 7, 2008.
Adapted from materials provided by CNRS.

Fausto Intilla
www.oloscience.com

California Has More Than 99% Chance Of A Big Earthquake WIthin 30 Years, Report Shows

Source:

http://www.sciencedaily.com/releases/2008/04/080414203459.htm

ScienceDaily (Apr. 15, 2008) — California has more than a 99% chance of having a magnitude 6.7 or larger earthquake within the next 30 years, according scientists using a new model to determine the probability of big quakes.
The likelihood of a major quake of magnitude 7.5 or greater in the next 30 years is 46%-and such a quake is most likely to occur in the southern half of the state.
The new study determined the probabilities that different parts of California will experience earthquake ruptures of various magnitudes. The new statewide probabilities are the result of a model that comprehensively combines information from seismology, earthquake geology, and geodesy (measuring precise locations on the Earth's surface). For the first time, probabilities for California having a large earthquake in the next 30 years can be forecast statewide.
"This new, comprehensive forecast advances our understanding of earthquakes and pulls together existing research with new techniques and data," explained USGS geophysicist and lead scientist Ned Field. "Planners, decision makers and California residents can use this information to improve public safety and mitigate damage before the next destructive earthquake occurs."
The new information is being provided to decision makers who establish local building codes, earthquake insurance rates, and emergency planning and will assist in more accurate planning for inevitable future large earthquakes.
The official earthquake forecasts, known as the "Uniform California Earthquake Rupture Forecast (UCERF)," were developed by a multidisciplinary group of scientists and engineers, known as the Working Group on California Earthquake Probabilities. Building on previous studies, the Working Group updated and developed the first-ever statewide, comprehensive model of California.
The organizations sponsoring the Working Group include the U.S. Geological Survey, the California Geological Survey and the Southern California Earthquake Center. An independent scientific review panel, as well as the California and National Earthquake Prediction Evaluation Councils, have evaluated the new UCERF study.
The consensus of the scientific community on forecasting California earthquakes allows for meaningful comparisons of earthquake probabilities in Los Angeles and the San Francisco Bay Area, as well as comparisons among several large faults.
The probability of a magnitude 6.7 or larger earthquake over the next 30 years striking the greater Los Angeles area is 67%, and in the San Francisco Bay Area it is 63%, similar to previous Bay Area estimates. For the entire California region, the fault with the highest probability of generating at least one magnitude 6.7 quake or larger is the southern San Andreas (59% in the next 30 years).
For northern California, the most likely source of such earthquakes is the Hayward-Rodgers Creek Fault (31% in the next 30 years). Such quakes can be deadly, as shown by the 1989 magnitude 6.9 Loma Prieta and the 1994 magnitude 6.7 Northridge earthquakes.
Earthquake probabilities for many parts of the state are similar to those in previous studies, but the new probabilities calculated for the Elsinore and San Jacinto Faults in southern California are about half those previously determined. For the far northwestern part of the State, a major source of earthquakes is the offshore 750-mile-long Cascadia Subduction Zone, the southern part of which extends about 150 miles into California. For the next 30 years there is a 10% probability of a magnitude 8 to 9 quake somewhere along that zone. Such quakes occur about once every 500 years on average.
The new model does not estimate the likelihood of shaking (seismic hazard) that would be caused by quakes. Even areas in the state with a low probability of fault rupture could experience shaking and damage from distant, powerful quakes. The U.S. Geological Survey (USGS) is incorporating the UCERF into its official estimate of California's seismic hazard, which in turn will be used to update building codes. Other subsequent studies will add information on the vulnerability of manmade structures to estimate expected losses, which is called "seismic risk." In these ways, the UCERF will help to increase public safety and community resilience to earthquake hazards.
The results of the UCERF study serve as a reminder that all Californians live in earthquake country and should be prepared. Although earthquakes cannot be prevented, the damage they do can be greatly reduced through prudent planning and preparedness. The ongoing work of the Southern California Earthquake Center, USGS, California Geological Survey, and other scientists in evaluating earthquake probabilities is part of the National Earthquake Hazard Reduction Program's efforts to safeguard lives and property from the future quakes that are certain to strike in California and elsewhere in the United States.
Adapted from materials provided by U.S. Geological Survey.

Fausto Intilla
www.oloscience.com

Ancient Method, 'Black Gold Agriculture' May Revolutionize Farming, Curb Global Warming

Source:

http://www.sciencedaily.com/releases/2008/04/080410153658.htm

ScienceDaily (Apr. 15, 2008) — Fifteen hundred years ago, tribes people from the central Amazon basin mixed their soil with charcoal derived from animal bone and tree bark. Today, at the site of this charcoal deposit, scientists have found some of the richest, most fertile soil in the world. Now this ancient, remarkably simple farming technique seems far ahead of the curve, holding promise as a carbon-negative strategy to rein in world hunger as well as greenhouse gases.

At the 235th national meeting of the American Chemical Society, scientists report that charcoal derived from heated biomass has an unprecedented ability to improve the fertility of soil -- one that surpasses compost, animal manure, and other well-known soil conditioners.
They also suggest that this so-called "biochar" profoundly enhances the natural carbon seizing ability of soil. Dubbed "black gold agriculture," scientists say this "revolutionary" farming technique can provide a cheap, straight-forward strategy to reduce greenhouse gases by trapping them in charcoal-laced soil.
"Charcoal fertilization can permanently increase soil organic matter content and improve soil quality, persisting in soil for hundreds to thousands of years," Mingxin Guo, Ph.D., and colleagues report. In what they describe as a "new and pioneering" ACS report -- the first systematic investigation of soil improvement by charcoal fertilization -- Guo found that soils receiving charcoal produced from organic wastes were much looser, absorbed significantly more water and nutrients and produced higher crop biomass. The authors, with Delaware State University, say "the results demonstrate that charcoal amendment is a revolutionary approach for long-term soil quality improvement."
Soil deterioration from depletion of organic matter is an increasingly serious global problem that contributes to hunger and malnutrition. Often a result of unsustainable farming, overuse of chemical fertilizers and drought, the main weapons to combat the problem --compost, animal manure and crop debris -- decompose rapidly.
"Earth's soil is the largest terrestrial pool of carbon," Guo said. "In other words, most of the earth's carbon is fixed in soil." But if this soil is intensively cultivated by tillage and chemical fertilization, organic matter in soil will be quickly decomposed into carbon dioxide by soil microbes and released into the atmosphere, leaving the soil compacted and nutrient-poor.
Applying raw organic materials to soil only provides a temporary solution, since the applied organic matter decomposes quickly. Converting this unutilized raw material into biochar, a non-toxic and stable fertilizer, could keep carbon in the soil and out of the atmosphere, says Guo.
"Speaking in terms of fertility and productivity, the soil quality will be improved. It is a long-term effect. After you apply it once, it will be there for hundreds of years," according to Guo. With its porous structure and high nutrient- and water-holding capabilities, biochar could become an extremely attractive option for commercial farmers and home gardeners looking for long-term soil improvement.
The researchers planted winter wheat in pots of soil in a greenhouse. Some pots were amended with two percent biochar, generated from readily available ingredients like tree leaves, corn stalk and wood chips. The other pots contained ordinary soil.
The biochar-infused soil showed vastly improved germination and growing rates compared to regular soil. Guo says that even a one-percent charcoal treatment would lead to improved crop yield.
Guo is "positive" that this ground-breaking farming technique can help feed countries with poor soil quality. "We hope this technology will be extended worldwide," says Guo.
"The production of current arable land could be significantly improved to provide more food and fiber for the growing populations. We want to call it the second agricultural revolution, or black gold revolution!"
He suggests that charcoal production has been practiced for at least 3000 years. But until now, nobody realized that this charcoal could improve soil fertility until archaeologists stumbled on the aforementioned Amazonian soil several years ago.
Biochar production is straightforward, involving a heating process known as pyrolysis. First, organic residue such as tree leaves and wood chips is packed into a metal container and sealed. Then, through a small hole on top, the container is heated and the material burns. The raw organic matter is transformed into black charcoal. Smokes generated during pyrolysis can also be collected and cooled down to form bio-oil, a renewable energy source, says Guo.
In lieu of patenting biochar, Guo says he is most interested in extending the technology into practice as soon as possible. To that end, his colleagues at Delaware State University are investigating a standardized production procedure for biochar. They also foresee long-term field studies are needed to validate and demonstrate the technology. Guo noted that downsides of biochar include transportation costs resulting from its bulk mass and a need to develop new tools to spread the granular fertilizer over large tracts of farmland.
The researchers are about to embark on a five-year study on the effect of "black gold" on spinach, green peppers, tomatoes and other crops. They seek the long-term effects of biochar fertilization on soil carbon changes, crop productivity and its effect of the soil microorganism community.
"Through this long-term work, we will show to people that biochar fertilization will significantly change our current conventional farming concepts," says Guo.
Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

Fausto Intilla

www.oloscience.com

Sea Salt Worsens Coastal Air Pollution

Source:

http://www.sciencedaily.com/releases/2008/04/080408163231.htm

ScienceDaily (Apr. 14, 2008) — Air pollution in the world's busiest ports and shipping regions may be markedly worse than previously suspected, according to a new study showing that industrial and shipping pollution is exacerbated when it combines with sunshine and salty sea air.

In a paper published in the journal Nature Geoscience, a team of researchers that included University of Calgary chemistry professor Hans Osthoff report that the disturbing phenomenon substantially raises the levels of ground-level ozone and other pollutants in coastal areas.
"We found unexpectedly high levels of certain air pollutants where pollution from cities and ships meets salt in the ocean air along the southeast coast of the United States," said Osthoff, who joined the U of C's Department of Chemistry last August. "It only makes sense that this is a problem everywhere industrial pollution meets the ocean, as is the case in many of the largest cities around the world. It also changes our view of the chemical transformations that occur in ship engine exhaust plumes, and tells us that emissions from marine vessels may be polluting the globe to a greater extent than currently estimated."
Dr. Osthoff was part of a National Oceanic and Atmospheric Administration (NOAA) team that spent six weeks monitoring air quality in busy shipping areas off the southeastern coast of the United States between Charleston, South Carolina and Houston, Texas, in the summer of 2006. The researchers found unexpectedly high levels of nitryl chloride (ClNO2), a chemical long suspected to be involved in ground-level ozone production along the coast.
They then determined that the compound is efficiently produced at night by the reaction of the nitrogen oxide N2O5 in polluted air with chloride from sea salt. With the help of sunlight, the chemical then splits into radicals that accelerate production of ozone and, potentially, fine particulate matter, which are the main components of air pollution. Their findings also show that up to 30 per cent of the ground-level ozone present in seaside cities such as Houston may be the result of pollution mixing with salt from ocean mist.
Dr. Osthoff intends to continue to work on halogen compounds at the University of Calgary.
"The Texas study covered only a very limited geographic area. We would like to find out to what extent this chemistry affects air quality in other regions, for example, the the Greater Vancouver area, or the Arctic," he said. "Our study indicates that halide salts such as chloride or bromide, which have been thought of as being relatively inert, may be playing a much greater role overall in the lower atmosphere."
The paper "High levels of nitryl chloride in the polluted subtropical marine boundary layer" is available in the April 6, 2008 advance online edition of the journal Nature Geoscience. The print version is scheduled to appear on May 1st, 2008.
Adapted from materials provided by University of Calgary, via EurekAlert!, a service of AAAS.

Fausto Intilla

www.oloscience.com

Geologists Discover New Way Of Estimating Size And Frequency Of Meteorite Impacts

Source: http://www.sciencedaily.com/releases/2008/04/080411160239.htm

ScienceDaily (Apr. 12, 2008) — Scientists have developed a new way of determining the size and frequency of meteorites that have collided with Earth.

Their work shows that the size of the meteorite that likely plummeted to Earth at the time of the Cretaceous-Tertiary (K-T) boundary 65 million years ago was four to six kilometers in diameter. The meteorite was the trigger, scientists believe, for the mass extinction of dinosaurs and other life forms.
François Paquay, a geologist at the University of Hawaii at Manoa (UHM), used variations (isotopes) of the rare element osmium in sediments at the ocean bottom to estimate the size of these meteorites. The results are published in this week's issue of the journal Science.
When meteorites collide with Earth, they carry a different osmium isotope ratio than the levels normally seen throughout the oceans.
"The vaporization of meteorites carries a pulse of this rare element into the area where they landed," says Rodey Batiza of the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research along with NSF's Division of Earth Sciences. "The osmium mixes throughout the ocean quickly. Records of these impact-induced changes in ocean chemistry are then preserved in deep-sea sediments."
Paquay analyzed samples from two sites, Ocean Drilling Program (ODP) site 1219 (located in the Equatorial Pacific), and ODP site 1090 (located off of the tip of South Africa) and measured osmium isotope levels during the late Eocene period, a time during which large meteorite impacts are known to have occurred.
"The record in marine sediments allowed us to discover how osmium changes in the ocean during and after an impact," says Paquay.
The scientists expect that this new approach to estimating impact size will become an important complement to a more well-known method based on iridium.
Paquay, along with co-author Gregory Ravizza of UHM and collaborators Tarun Dalai from the Indian Institute of Technology and Bernhard Peucker-Ehrenbrink from the Woods Hole Oceanographic Institution, also used this method to make estimates of impact size at the K-T boundary.
Even though these method works well for the K-T impact, it would break down for an event larger than that: the meteorite contribution of osmium to the oceans would overwhelm existing levels of the element, researchers believe, making it impossible to sort out the osmium's origin.
Under the assumption that all the osmium carried by meteorites is dissolved in seawater, the geologists were able to use their method to estimate the size of the K-T meteorite as four to six kilometers in diameter.
The potential for recognizing previously unknown impacts is an important outcome of this research, the scientists say.
"We know there were two big impacts, and can now give an interpretation of how the oceans behaved during these impacts," says Paquay. "Now we can look at other impact events, both large and small."
Adapted from materials provided by National Science Foundation.

Fausto Intilla - www.oloscience.com

Unusual Earthquake Swarm Off Oregon Coast Puzzles Scientists

Source: http://www.sciencedaily.com/releases/2008/04/080413184801.htm

ScienceDaily (Apr. 14, 2008) — Scientists at Oregon State University’s Hatfield Marine Science Center have recorded more than 600 earthquakes in the last 10 days off the central Oregon coast in an area not typically known for a high degree of seismic activity.
This earthquake “swarm” is unique, according to OSU marine geologist Robert Dziak, because it is occurring within the middle of the Juan de Fuca plate – away from the major, regional tectonic boundaries.
“In the 17 years we’ve been monitoring the ocean through hydrophone recordings, we’ve never seen a swarm of earthquakes in an area such as this,” Dziak said. “We’re not certain what it means. But we hope to have a ship divert to the site and take some water samples that may help us learn more.” The water samples may indicate whether the process causing the earthquakes is tectonic or hydrothermal, he added.
At least three of the earthquakes have been of a magnitude of 5.0 or higher, Dziak said, which also is unusual. On Monday (April 7), the largest event took place, which was a 5.4 quake. Seismic activity has continued through the week and a 5.0 tremor hit on Thursday. Numerous small quakes have continued in between the periodic larger events.
Few, if any, of these earthquakes would be felt on shore, Dziak said, because they originate offshore and deep within the ocean.
The earthquakes are located about 150 nautical miles southwest of Newport, Ore., in a basin between two subsurface “faulted” geologic features rising out of the deep abyssal sediments. The hill closest to the swarm location appears to be on a curved structure edging out in a northwestern direction from the Blanco Transform Fault toward the Juan de Fuca ridge, Dziak said.
Analysis of seismic “decay” rates, which look at the decreasing intensity of the tremors as they radiate outward, suggest that the earthquakes are not the usual sequence of a primary event followed by a series of aftershocks, Dziak said.
“Some process going on down there is sustaining a high stress rate in the crust,” he pointed out.
Dziak and his colleagues are monitoring the earthquakes through a system of hydrophones located on the ocean floor. The network – called the Sound Surveillance System, or SOSUS – was used during the decades of the Cold War to monitor submarine activity in the northern Pacific Ocean. As the Cold War ebbed, these and other unique military assets were offered to civilian researchers performing environmental studies, Dziak said.
Hatfield Marine Science Center researchers also have created their own portable hydrophones, which Dziak has deployed in Antarctica to listen for seismic activity in that region. The sensitive hydrophones also have recorded a symphony of sounds revealing not only undersea earthquakes, but the movement of massive icebergs, and vocalizations of whales, penguins, elephant seals and other marine species.
This isn’t the first time the researchers have recorded earthquake swarms off the Oregon coast, Dziak said. In 2005, they recorded thousands of small quakes within a couple of weeks along the Juan de Fuca Ridge northwest of Astoria. Those earthquakes were smaller, he pointed out, and located along the tectonic plate boundary.
This is the eighth such swarm over the past dozen years, Dziak said, and the first seven were likely because of volcanic activity on the Juan de Fuca ridge. The plate doesn't move in a continuous manner and some parts move faster than others. Movement generally occurs when magma is injected into the ocean crust and pushes the plates apart.
“When it does, these swarms occur and sometimes lava breaks through onto the seafloor,” Dziak pointed out. “Usually, the plate moves at about the rate a fingernail might grow – say three centimeters a year. But when these swarms take place, the movement may be more like a meter in a two-week period."
But this eighth swarm may be different.
“The fact that it’s taking place in the middle of the plate, and not a boundary, is puzzling,” Dziak admitted. “It’s something worth keeping an eye on.”
Adapted from materials provided by Oregon State University.

Fausto Intilla - www.oloscience.com