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Antarctic salty soil sucks water out of atmosphere: Could it happen on Mars?

CORVALLIS, Ore. – The frigid McMurdo Dry Valleys in Antarctica are a cold, polar desert, yet the sandy soils there are frequently dotted with moist patches in the spring despite a lack of snowmelt and no possibility of rain.

A new study, led by an Oregon State University geologist, has found that that the salty soils in the region actually suck moisture out of the atmosphere, raising the possibility that such a process could take place on Mars or on other planets.

The study, which was supported by the National Science Foundation, has been published online this week in the journal Geophysical Research Letters, and will appear in a forthcoming printed edition.

Joseph Levy, a post-doctoral researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences, said it takes a combination of the right kinds of salts and sufficient humidity to make the process work. But those ingredients are present on Mars and, in fact, in many desert areas on Earth, he pointed out.

“The soils in the area have a fair amount of salt from sea spray and from ancient fjords that flooded the region,” said Levy, who earned his doctorate at Brown University. “Salts from snowflakes also settle into the valleys and can form areas of very salty soil. With the right kinds of salts, and enough humidity, those salty soils suck the water right out of the air.

“If you have sodium chloride, or table salt, you may need a day with 75 percent humidity to make it work,” he added. “But if you have calcium chloride, even on a frigid day, you only need a humidity level above 35 percent to trigger the response.”

Once a brine forms by sucking water vapor out of the air, Levy said, the brine will keep collecting water vapor until it equalizes with the atmosphere.

“It’s kind of like a siphon made from salt.”

Levy and his colleagues, from Portland State University and Ohio State University, found that the wet soils created by this phenomenon were 3-5 times more water-rich than surrounding soils – and they were also full of organic matter, including microbes, enhancing the potential for life on Mars. The elevated salt content also depresses the freezing temperature of the groundwater, which continues to draw moisture out of the air when other wet areas in the valleys begin to freeze in the winter.

Though Mars, in general, has lower humidity than most places on Earth, studies have shown that it is sufficient to reach the thresholds that Levy and his colleagues have documented. The salty soils also are present on the Red Planet, which makes the upcoming landing of the Mars Science Laboratory this summer even more tantalizing.

Levy said the science team discovered the process as part of “walking around geology” – a result of observing the mysterious patches of wet soil in Antarctica, and then exploring their causes. Through soil excavations and other studies, they eliminated the possibility of groundwater, snow melt, and glacial runoff. Then they began investigating the salty properties of the soil, and discovered that the McMurdo Dry Valleys weather stations had reported several days of high humidity earlier in the spring, leading them to their discovery of the vapor transfer.

“It seems kind of odd, but it really works,” Levy said. “Before one of our trips, I put a bowl of the dried, salty soil and a jar of water into a sealed Tupperware container and left it on my shelf. When I came back, the water had transferred from the jar to the salt and created brine.

“I knew it would work,” he added with a laugh, “but somehow it still surprised me that it did.”

Evidence of the salty nature of the McMurdo Dry Valleys is everywhere, Levy said. Salts are found in the soils, along seasonal streams, and even under glaciers. Don Juan Pond, the saltiest body of water on Earth, is found in Wright Valley, the valley adjacent to the wet patch study area.

“The conditions for creating this new water source into the permafrost are perfect,” Levy said, “but this isn’t the only place where this could or does happen. It takes an arid region to create the salty soils, and enough humidity to make the transference work, but the rest of it is just physics and chemistry.”

Other authors on the study include Andrew Fountain, Portland State University, and Kathy Welch and W. Berry Lyons, Ohio State University.

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Joe Levy, 541-737-4915

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McMurdo Dry Valleys
Polar desert sucks water from the atmosphere

"Patchiness” altering perceptions of ocean predators, prey

CORVALLIS, Ore. – Scientists and resource managers have always been interested in how animals in the ocean find their prey and the relative health of marine ecosystems is often judged by the abundance of food for the myriad species living there.

But new studies focusing on ocean “patchiness” suggest that it isn’t just the total amount of prey that is important to predators – it is the density of the food source, and ease of access to it.

Kelly Benoit-Bird, an Oregon State University oceanographer, outlined the importance of this new way of looking at ocean habitats during a keynote talk Wednesday (Feb. 22) at the 2012 Ocean Sciences meeting in Salt Lake City, Utah.

Sophisticated new technologies are helping scientists document how predators target prey, from zooplankton feasting on phytoplankton, to dolphins teaming up to devour micronekton, according to Benoit-Bird, who received a prestigious MacArthur Fellowship in 2010.

“We used to think that the size and abundance of prey was what mattered most,” said Benoit-Bird, a marine ecologist who studies relationships among marine species. “But patchiness is ubiquitous in marine systems and ultimately dictates the behavior of many animals and their relationships to the environment. We need to change our way of thinking about how we look at predator-prey relationships.”

Benoit-Bird pointed to a section of the Bering Sea, where her research with collaborators had estimated the abundance of krill. Closer examination through the use of acoustics, however, found that the distribution of krill was not at all uniform – and this may explain why two colonies of fur seals and seabirds were faring poorly, but a third was healthy.

“The amount of food near the third colony was not abundant,” she said, “but what was there was sufficiently dense – and at the right depth – that made it accessible to predators.”

The ability to use acoustics to track animal behavior underwater is opening new avenues to researchers.  During their study in the Bering Sea, Benoit-Bird and her colleagues discovered that they could also use sonar to plot the dives of thick-billed murres, which would plunge up to 200 meters below the surface in search of the krill.

Although the krill were spread throughout the water column, the murres ended up focusing on areas where the patches of krill were the densest.

“The murres are amazingly good at diving right down to the best patches,” Benoit-Bird pointed out. “We don’t know just how they are able to identify them, but 10 years ago, we wouldn’t have known that they had that ability. Now we can use high-frequency sound waves to look at krill, different frequencies to look at murres, and still others to look at squid, dolphins and other animals.

“And everywhere we’ve looked the same pattern occurs,” she added. “It is the distribution of food, not the biomass, which is important.”

An associate professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State University, Benoit-Bird has received young investigator or early career awards from the Office of Naval Research, the White House and the American Geophysical Union. She also has received honors from the Acoustical Society of America, which has used her as a model scientist in publications aimed at middle school students.

Her work has taken her around the world, including Hawaii where she has used acoustics to study the sophisticated feeding behavior of spinner dolphins. Those studies, she says, helped lead to new revelations about the importance of patchiness.

Ocean physics in the region results in long, thin layers of phytoplankton that may stretch for miles, but are only a few inches thick and a few meters below the surface. Benoit-Bird and her colleagues discovered a layer of zooplankton – tiny animals that feed on the plankton – treading water a meter below to be near the food source. Next up in the food chain were micronekton, larger pelagic fish and crustaceans that would spend the day 600 to 1,000 meters beneath the surface, then come up to the continental shelf at night to target the zooplankton. And the spinner dolphins would emerge at night, where they could reach the depth of the micronekton.

“The phytoplankton were responding to ocean physics,” Benoit-Bird said, “but all of the others in the food chain were targeting their prey by focusing on the densest patches. We got to the point where we could predict with 70 percent accuracy where the dolphins would show up based just on the phytoplankton density – without even considering the zooplankton and micronekton distribution.”

Ocean “patchiness” is not a new concept, Benoit-Bird says, but may have been under-appreciated in importance.

“If you’re a murre that is diving a hundred meters below the surface to find food, you want to maximize the payoff for all of the energy you’re expending,” Benoit-Bird said. “Now we need more research to determine how different species are able to determine where the best patches are.”

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Kelly Benoit-Bird, 541-737-2063

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Dolphins circling prey
Dense patches of food draw ocean predators

For disaster debris arriving from Japan, radiation least of the concerns

CORVALLIS, Ore. – The first anniversary is approaching of the March, 2011, earthquake and tsunami that devastated Fukushima, Japan, and later this year debris from that event should begin to wash up on U.S. shores – and one question many have asked is whether that will pose a radiation risk.

The simple answer is, no.

Nuclear radiation health experts from Oregon State University who have researched this issue following the meltdown of the Fukushima Dai-ichi nuclear plant say the minor amounts of deposition on the debris field scattered in the ocean will have long since dissipated, decayed or been washed away by months of pounding in ocean waves.

However, that’s not to say that all of the debris that reaches Pacific Coast shores in the United States and Canada will be harmless.

“The tsunami impacted several industrial areas and no doubt swept out to sea many things like bottled chemicals or other compounds that could be toxic,” said Kathryn Higley, professor and head of the Department of Nuclear Engineering and Radiation Health Physics at OSU.

“If you see something on the beach that looks like it may have come from this accident, you shouldn’t assume that it’s safe,” Higley said. “People should treat these debris with common sense; there could be some things mixed in there that are dangerous. But it will have nothing to do with radioactive contamination.”

Higley and other OSU experts have been active in studying the Fukushima accident since it occurred, and are now doing research to help scientists in Japan better understand such issues as uptake of radioactive contamination by plants growing near the site of the accident. They also studied marine and fishery impacts near Japan soon after the incident.

“In the city and fields near Fukushima, there are still areas with substantial contamination, and it may be a few years before all of this is dealt with,” Higley said. “But researchers from all over the world are contributing information on innovative ways to help this area recover, including some lessons learned from the much more serious Chernobyl accident in 1986 in the Ukraine.”

Some of the technology to deal with this is complex. Other approaches, she said, can be fairly low-tech – removal of leaf litter, washing, plowing the ground, collecting and concentrating water runoff.

The repercussions of the event in the ocean, however, and implications for distant shores are much more subdued. Most of the discharge that was of concern was radionuclides of iodine and cesium, which were deposited on widely dispersed, floating marine debris days after the tsunami. Most of the iodine by now will have disappeared due to radioactive decay, and the cesium washed off and diluted in the ocean.

“There are a lot of misconceptions about radioactivity,” Higley said. “Many people believe that if it can be measured, it’s harmful. But we live in a world of radiation coming to us from the sun, or naturally present in the earth, or even from our own bodies.

“There are higher natural levels of radiation found all around the Rocky Mountains, for instance,” she said. “And we can still measure radioactive contaminants in nature from old atmospheric nuclear weapons tests more than 50 years ago.”

Like most of those other forms of radiation, Higley said, any measurable radioactivity found on debris from Fukushima should be at very low levels and of no health concern – much less, for instance, than a person might receive in a single X-ray.

Debris from Japan should start to arrive in the U.S. and Canada late this year or in 2013 following normal ocean currents, say other OSU experts who are studying this issue. When they do, some aspects of them might be dangerous – a half-filled, floating, sealed bottle of a toxic chemical, for instance. So people should exercise caution.

But they don’t need to worry about radiation.

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Kathryn Higley, 541-737-0675

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Radiation uptake

Kathryn Higley

Aftershocks of Japan disaster being felt in U.S. earthquake planning

CORVALLIS, Ore. – The repercussions of last year’s subduction zone earthquake and tsunami in Japan are now being felt in the Pacific Northwest, as experts and disaster managers better understand the enormous risks facing this region, plan for the challenges ahead and prioritize the most urgent needs.

Before the event, scientists knew that similar concerns faced Oregon, Washington, northern California and British Columbia from the Cascadia Subduction Zone. But they have now seen how such long-lasting events produce soil “liquefaction” far worse than expected, the potential for devastated roads and bridges, a collapsed infrastructure and even threats to their economic future.

“Just in Oregon we’ve got a billion dollar problem, but we don’t have a billion dollars,” said Scott Ashford, professor and interim dean of the College of Engineering at Oregon State University, and one of the international engineering experts who toured the affected area in Japan last year shortly after the disaster.

“The challenge for Oregon and our neighboring states is to prioritize the concerns, and figure out some way to preserve the most critical lifelines – key roads, airports, port facilities and utility networks,” Ashford said. “In Japan, nearly 30,000 people died, many in the days after the disaster because no one could reach them. We don’t want that to happen here, and we don’t want our economy to collapse.”

The Japanese event has galvanized some action, Ashford said, but much more remains to be done. It prompted the legislature to call for an Oregon Resilience Plan that will explore many of these issues – an emergency transportation plan, needed seismic upgrades, ways to protect life and public safety and allow a shattered region to rebuild.

OSU is working closely with the Oregon Department of Transportation and other state agencies to assist with these efforts, and also just joined the Pacific Earthquake Engineering Research Center, an initiative to collaborate with all of the leading academic institutions in this field on the West Coast.

One of the primary lessons from Japan, Ashford says, is the enormous damage done by liquefaction - a continued shaking of the ground that turns soils into mush. In events such as this, it is amplified by the sheer length of the event, an earthquake that can shake not just for 30 seconds but up to five minutes.

Many of the soils in Portland, Ore., parts of the Willamette Valley and other areas of Oregon, Washington and California are particularly vulnerable to this phenomenon, Ashford said, which can magnify the distance and extent of damage.

“In Japan, entire structures were tilting and sinking into the sediments, even while they remained intact,” Ashford said. “The shifts in soil destroyed water, sewer and gas pipelines, crippling the utilities and infrastructure these communities need to function. We saw some places that sank as much as four feet.”

The data provided by analyzing the Japanese earthquake is now being used by OSU and others to improve understanding of this soil phenomenon and better prepare for it. Future construction in some places may make more use of techniques known to reduce liquefaction, such as better compaction to make soils dense, or use of reinforcing stone columns.

Many areas from northern California to British Columbia have younger soils vulnerable to liquefaction - on the coast, near river deposits or in areas with filled ground. The “young” sediments, in geologic terms, may be those deposited within the past 10,000 years or more. In Oregon, for instance, that describes much of downtown Portland, the Portland International Airport, nearby industrial facilities and other cities and parts of the Willamette Valley.

The Oregon Department of Transportation has concluded that 1,100 bridges in Oregon are at risk, and fewer than 15 percent of them have been retrofitted to prevent collapse. Lateral movement is also a concern.

“Buildings that are built on soils vulnerable to liquefaction not only tend to sink or tilt during an earthquake, but slide downhill if there’s any slope, like toward a nearby river,” Ashford said. “This is called lateral spreading. In Portland we might expect this sideways sliding of more than four feet in some cases, more than enough to tear apart buildings and buried pipelines.”

Japan had excellent building codes, researchers say, and was far better prepared for this type of earthquake than the U.S. will be. Much of the “legacy” infrastructure in the Pacific Northwest was built before these risks were known.

“The disaster in Japan just clarifies what we need to do,” Ashford said. “And it’s not something we can do in a year or two, but something that will take a decade or two. At stake are the lives of our people and the future of our economy, and that’s something that should matter to every individual.”

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Scott Ashford, 541-737-5232

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Sinking structures
Sinking building


Settlement caused by liquefaction

Liquefaction


Video of the liquefaction

http://bit.ly/dK6mfa

OSU receives full accreditation from international association

CORVALLIS, Ore. – Oregon State University has been awarded full accreditation for the care and facilities of its animal research and teaching programs by the Association for Assessment and Accreditation of Laboratory Animal Care, International.

AAALAC accreditation is recognized internationally as the “gold standard” for animal care and use programs, OSU officials say.

“Our participation in the rigorous AAALAC accreditation process demonstrates our commitment to humane and responsible animal use in research, instruction and testing, as well as dedication to excellent science,” said Rick Spinrad, OSU’s vice president for research.

OSU becomes just the 20th land grant institution with complete institutional accreditation. The comprehensive overview and site evaluation by the association accreditation team included facilities and processes of the university’s College of Agricultural Sciences, Agricultural Experiment Station, College of Veterinary Medicine, Hatfield Marine Science Center, Oregon Hatchery Research Center, and the entire campus animal research endeavor.

There are 854 accredited institutions or units worldwide; of these, OSU is among the 60 largest.

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Rick Spinrad, 541-737- 0664

Tai chi may help patients with Parkinson’s disease regain balance, reduce falls

CORVALLIS, Ore. – A newly published study has found that tai chai, an ancient Chinese martial art, may help Parkinson’s disease patients not only regain strength and balance, but also reduce potentially life-threatening falls.

The study, conducted by researchers in Corvallis, Salem, Eugene and Portland, Oregon, is in the current issue of The New England Journal of Medicine.

In the study, Parkinson’s patients were divided into three groups. One group participated in a resistance training program with weighted vests and weights, designed by Oregon State University researcher Gianni Maddalozzo. Another, which acted as the control group, did stretching classes. The third group took a modified tai chi class designed by Fuzhong Li, the lead author of the study. Li is with the Oregon Research Institute in Eugene and earned his doctorate in the exercise and sport science program at OSU.

Each group did a 60-minute class twice a week for 24 weeks. The patients in the tai chi group had significantly better balance, had better overall physical functioning and had a much lower incidence of falls. In fact, participants in the tai chi group had 67 percent fewer falls than those in the stretching group.

Maddalozzo, a coauthor on the study, said the reduced rate of falling is a significant finding.

“Falls can be detrimental, not only to those with Parkinson’s, but for many people including aging populations, diabetics, people with osteoporosis,” he said. “More than 30 percent of serious falls occur in the home, so what we tend to see is that people develop a serious fear of falling that leads to a more sedentary lifestyle, which is the opposite of what they should be doing.”

Parkinson’s is a disorder of the nervous system that affects motor control and movement. Patients affected by the disease have substantially impaired balance that can lead to serious if not deadly falls. Lead author Li practices tai chi, a martial art marked by slow, focused movements focused on meditation and relaxation.

 “Clinically, as an effective and safe exercise regimen, tai chi may be used as an add-on to existing physical therapy or rehabilitation programs as part of a balance training protocol or to address some of the key movement disorders in Parkinson’s,” Li said.

Maddalozzo said because tai chi has been shown to help Parkinson’s patients restore balance and regain strength, he believes it could be useful to a wide variety of people. Li agrees, saying that researchers have found positive results with older adults, including reducing falls by 47 to 55 percent.

“Tai chi has also shown to be beneficial in reducing pain in people with fibromyalgia and osteoarthritis, ameliorating sleep disturbances, and helping to decrease blood pressure,” he said. “Overall, accumulating evidence suggests that tai chi may be efficacious as a behavioral medicine approach for the prevention and rehabilitation of chronic diseases and dysfunctional mental and physical conditions commonly associated with advancing age.”

Researchers from the Oregon Medical Group, the PeaceHealth Medical Group–Oregon, Willamette University, BPM Physical Therapy Center, Oregon Health and Science University and Oregon Neurology Associates contributed to this study, which was funded by the National Institute of Neurological Disorders and Stroke.

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Gianni Maddalozzo, 541-737-6802

OSU researcher part of Mars rover science team

CORVALLIS, Ore. – An Oregon State University researcher, who has spent much of his recent career exploring life in volcanic rocks, has been selected as a participating scientist for the new Mars expedition that may bring scientists closer to discovering life on another planet.

NASA launched the Mars Science Laboratory on Nov. 26 of last year and the mission includes a rover named “Curiosity” that will explore the Martian landscape after landing there this August.

Martin Fisk and 28 other researchers selected as participating scientists will join other science-team members and engineers in guiding Curiosity. The mission will investigate whether an area of Mars has ever been conducive to harboring life, but is not designed for detecting life, NASA officials say.

“One goal is to identify key samples of the rock and soil and identify those areas that might represent habitable environments,” Fisk said, “so that a future mission can select the right rocks to be returned to Earth.”

Fisk is a professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State. He was part of a research team that in 1998 discovered evidence of rock-eating microbes living nearly a mile beneath the ocean floor. Trails and tracks in the glassy basalt contained microbial DNA. The rocks have the basic elements for life, he pointed out, include carbon, phosphorous and nitrogen – and needed only water to complete the formula. Groundwater seeping through the ocean floor could easily provide that.

“Under those conditions,” Fisk said at the time, “microbes could live beneath any rocky planet.”

The Mars Science Laboratory science payload will not have the capacity to detect tracks and trails of the type Fisk has studied; however it does have the capacity to detect environments similar to those where tracks and trails formed on Earth.

Five years ago, Fisk examined part of a meteorite that originated from Mars and found the same kinds of tracks and trails left by the subterranean microbes on Earth, but he was unable to locate DNA in the Martian sample. More than 30 such meteorites that have originated from Mars have been identified; they carry a unique chemical signature based on the gases trapped within. Scientists speculate that the rocks were “blasted” off the planet when Mars was struck by asteroids or comets, eventually entering the Earth’s orbit and crashing to the ground.

One such meteorite is called Nakhla, which landed in Egypt in 1911 and provided the source material for Fisk’s study. Scientists dated the igneous rock fragment from Nakhla, which weighs about 20 pounds, at 1.3 billion years in age. They believe it was exposed to water about 600 million years ago; however, if life was present then, evidence for it has not yet been found in the meteorite.

Fisk and his colleagues have also found bacteria in a 4,000-foot hole drilled into volcanic rock on the island of Hawaii near Hilo, fueling further speculation that life may exist below the surface of Mars. And late in 2011, he and his colleagues from OSU and Portland State University reported the discovery of rock-eating microbes in a lava tube near Oregon’s Newberry Crater. What made that discovery interesting was the microbes consumed organic material (sugar) in the laboratory, but when the scientists lowered the temperature and oxygen levels to near Mars-like conditions, the microbes began consuming olivine – a common material found in the Newberry volcanic rocks and on Mars.

Scientists believe Mars historically has had life-sustaining water, and may still have.

“Mars is thought to have gone through three major stages,” Fisk said. “Initially, the planet had water near the surface, and then it evaporated and the surface was covered by sulfate salts, which are still preserved today. Now it appears to be in an oxidative phase, where there is ice as well as a very real possibility that water exists below the surface.”

Fisk will spend a couple of weeks in March and June at the Jet Propulsion Laboratory in Pasadena, Calif., where he and other participating scientists will familiarize themselves with the operation of the Curiosity rover and its 10 instruments. For three months after the Mars Science Laboratory lands, he and the other members of the science team will provide daily instructions to Curiosity. Then for the duration of the two-year mission, the team will meet online to decide on daily operations and long-term plans.

Ideally, the scientists would like to identify organic matter in the shallow subsurface, Fisk said, but it would be a major step forward to document chemical differences in the rock and be able to visually identify them by color, texture or layering so they can more easily locate future sites for retrieval.

The rover will include a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, and instrumentation to analyze the samples inside the rover. It will also include a laser for vaporizing rock and checking its elemental composition from a distance.

“This is a huge project and the scientists and engineers have been developing the instrumentation for 6-8 years,” Fisk said. “There are 10 instruments on the rover and each instrument has a science team of 10 to 20 people, along with the community of (29) scientists invited to participate.

“It should make for a fascinating summer.”

The mission is scheduled to touch down in August and place the rover Curiosity near the foot of a mountain inside Gale Crater on Aug. 6. If all goes according to plan, the rover will then investigate the planet for nearly two years.

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Martin Fisk, 541-737-1458

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Fisk and microbe track Martin Fisk

New study: Climate sensitivity to CO2 more limited than extreme projections

CORVALLIS, Ore. – A new study suggests that the rate of global warming from doubling of atmospheric carbon dioxide may be less than the most dire estimates of some previous studies – and, in fact, may be less severe than projected by the Intergovernmental Panel on Climate Change report in 2007.

Authors of the study, which was funded by the National Science Foundation’s Paleoclimate Program and published online this week in the journal Science, say that global warming is real and that increases in atmospheric CO2 will have multiple serious impacts.

However, the most Draconian projections of temperature increases from the doubling of CO2 are unlikely.

“Many previous climate sensitivity studies have looked at the past only from 1850 through today, and not fully integrated paleoclimate date, especially on a global scale,” said Andreas Schmittner, an Oregon State University researcher and lead author on the Science article. “When you reconstruct sea and land surface temperatures from the peak of the last Ice Age 21,000 years ago – which is referred to as the Last Glacial Maximum – and compare it with climate model simulations of that period, you get a much different picture.

“If these paleoclimatic constraints apply to the future, as predicted by our model, the results imply less probability of extreme climatic change than previously thought,” Schmittner added.

Scientists have struggled for years trying to quantify “climate sensitivity” – which is how the Earth will respond to projected increases of atmospheric carbon dioxide. The 2007 IPCC report estimated that the air near the surface of the Earth would warm on average by 2 to 4.5 degrees (Celsius) with a doubling of atmospheric CO2 from pre-industrial standards. The mean, or “expected value” increase in the IPCC estimates was 3.0 degrees; most climate model studies use the doubling of CO2 as a basic index.

Some previous studies have claimed the impacts could be much more severe – as much as 10 degrees or higher with a doubling of CO2 – although these projections come with an acknowledged low probability. Studies based on data going back only to 1850 are affected by large uncertainties in the effects of dust and other small particles in the air that reflect sunlight and can influence clouds, known as “aerosol forcing,” or by the absorption of heat by the oceans, the researchers say.

To lower the degree of uncertainty, Schmittner and his colleagues used a climate model with more data and found that there are constraints that preclude very high levels of climate sensitivity.

The researchers compiled land and ocean surface temperature reconstructions from the Last Glacial Maximum and created a global map of those temperatures. During this time, atmospheric CO2 was about a third less than before the Industrial Revolution, and levels of methane and nitrous oxide were much lower. Because much of the northern latitudes were covered in ice and snow, sea levels were lower, the climate was drier (less precipitation), and there was more dust in the air.

All these factor, which contributed to cooling the Earth’s surface, were included in their climate model simulations.

The new data changed the assessment of climate models in many ways, said Schmittner, an associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. The researchers’ reconstruction of temperatures has greater spatial coverage and showed less cooling during the Ice Age than most previous studies.

High sensitivity climate models – more than 6 degrees – suggest that the low levels of atmospheric CO2 during the Last Glacial Maximum would result in a “runaway effect” that would have left the Earth completely ice-covered.

“Clearly, that didn’t happen,” Schmittner said. “Though the Earth then was covered by much more ice and snow than it is today, the ice sheets didn’t extend beyond latitudes of about 40 degrees, and the tropics and subtropics were largely ice-free – except at high altitudes. These high-sensitivity models overestimate cooling.”

On the other hand, models with low climate sensitivity – less than 1.3 degrees – underestimate the cooling almost everywhere at the Last Glacial Maximum, the researchers say. The closest match, with a much lower degree of uncertainty than most other studies, suggests climate sensitivity is about 2.4 degrees.

However, uncertainty levels may be underestimated because the model simulations did not take into account uncertainties arising from how cloud changes reflect sunlight, Schmittner said.

Reconstructing sea and land surface temperatures from 21,000 years ago is a complex task involving the examination of ices cores, bore holes, fossils of marine and terrestrial organisms, seafloor sediments and other factors. Sediment cores, for example, contain different biological assemblages found in different temperature regimes and can be used to infer past temperatures based on analogs in modern ocean conditions.

“When we first looked at the paleoclimatic data, I was struck by the small cooling of the ocean,” Schmittner said. “On average, the ocean was only about two degrees (Celsius) cooler than it is today, yet the planet was completely different – huge ice sheets over North America and northern Europe, more sea ice and snow, different vegetation, lower sea levels and more dust in the air.

“It shows that even very small changes in the ocean’s surface temperature can have an enormous impact elsewhere, particularly over land areas at mid- to high-latitudes,” he added.

Schmittner said continued unabated fossil fuel use could lead to similar warming of the sea surface as reconstruction shows happened between the Last Glacial Maximum and today.

“Hence, drastic changes over land can be expected,” he said. “However, our study implies that we still have time to prevent that from happening, if we make a concerted effort to change course soon.”

Other authors on the study include Peter Clark and Alan Mix of OSU; Nathan Urban, Princeton University; Jeremy Shakun, Harvard University; Natalie Mahowald, Cornell University; Patrick Bartlein, University of Oregon; and Antoni Rosell-Mele, University of Barcelona.

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Andreas Schmittner, 541-737-9952

Unseen devastation from tsunamis can destroy coral reefs

CORVALLIS, Ore. – The large tsunami two years ago in American Samoa has given scientists a chance to examine an issue that often seems of little significance in the immediate aftermath of these massive disasters – the little-seen, rarely studied but often frightening damage done to offshore coral reefs.

A new study by scientists from Oregon and Michigan, done with a remotely operated undersea vehicle, or ROV, surveyed large areas of that area’s coral reefs, and revealed significant damage from sediment, debris, and the enormous forces of both the incoming and outgoing waves.

Corals are delicate living organisms that can only survive in shallow, nearshore areas where they get adequate sunlight. That’s also where the tsunami wave action is most violent, and they are especially vulnerable to its impacts – but often ignored in the understandable concern about terrestrial damage and loss of life.

“Very little until now has been known about the impact of tsunamis on coral reefs,” said Solomon Yim, a professor of structural and ocean engineering at Oregon State University and co-author of the study, which was supported by the National Science Foundation.

“These are huge forces and often these events have happened in remote locations of the world where we had little opportunity to study them,” Yim said. “American Samoa gave us the chance to use some very sophisticated equipment to gain a much better understanding of what damage is being done to coral reefs, and what might be done in the future to help reduce it.”

On Sept. 29, 2009, a magnitude 8.3 subduction zone earthquake near American Samoa sent waves crashing into many islands, destroying buildings and eroding coastlines with waves up to 20 feet high that came almost a mile inland and killed more than 180 people. It was the world’s largest earthquake that year.

The onshore devastation was heavy. Although not seen at the time, so was the underwater damage to coral reefs.

“We found tires, clothing, sheet metal roofs, and window frames littered on the reefs,” Yim said. “Much of the coral was broken or covered with sediments, and some of it died as a result. Both the run-up and run-down of the tsunami waves were very destructive. It will probably take years to decades for the reef to recover.”

The sediments and debris carried by the rapid drawdown back into the sea can be harmful to the delicate marine ecosystem, the researchers noted in their report. They introduce bacteria and toxic chemicals, erode the seafloor and destroy the reef.

Work with the ROV examined the reefs five weeks after the tsunami, when they were still deeply scarred. Some corals were ripped up and tossed onshore, others broken and sucked back into deep water. In either case they would not survive. Hours of video footage were made of the damage, and the research indicated the drawdown of the water was even more destructive than the incoming waves.

Most of the damage and debris was found in comparatively shallow ocean waters, about 30 to 70 feet deep.

Since so little is known about the damage to coral reefs by tsunamis, more studies are needed to examine the influence of water depth, three-dimensional effects, wave-wave interactions and coral strengths, the researchers said.

“In the aftermath of a destructive tsunami, there may be some things we could do to aid reef recovery after the more immediate needs onshore are tended to,” Yim said. “There’s probably not much we can do about the fine sediments that bury the coral, but we could perhaps clean up some of the larger debris and building materials like sheet metal roofing that cover up the coral. It’s a significant challenge.”

Collaborating on this research, which was published in Marine Geology, a professional journal, were Y.L. Young and D.L. Witt, scientists from the University of Michigan. The research was funded by the National Science Foundation and the video was produced by Paul Hillman of the National Oceanic and Atmospheric Administration.

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Solomon Yim, 541-737-6894

OSU establishes center for Latino/Latina studies

CORVALLIS, Ore. – Oregon State University has established a new Center for Latino/Latina Studies and Engagement, and named a prominent faculty member as interim director.

Susana Rivera-Mills, a professor of Spanish and diversity advancement, will direct the new center, known as CL@SE (pronounced claw-SAY), which is designed to meet the research and outreach needs relating to Oregon’s growing Latino population. Rivera-Mills also is the associate dean of the College of Liberal Arts, and has been an active leader on the OSU campus in advancing diversity.

The new center emerged from discussions by leadership from OSU, the Oregon University System, and the State Board of Higher Education, according to Sabah Randhawa, OSU provost and executive vice president.

“Research and outreach on issues surrounding the Latino population are critical to enable success of this growing population segment in Oregon,” Randhawa said. “For OSU, the work will directly contribute to enhancing student retention and success of Latino students, and of all under-represented minorities.”

The new center will integrate studies of Latino communities in the United States with analyses of their histories, politics, cultures and societies, officials say. Among the research themes that will be explored are colonialism, race, gender, nationalism, globalism, immigration, economic development, language and identity.

“The center will promote engaged research and outreach devoted to advancing knowledge and understanding of Latino contributions and the issues surrounding this population in our state, region and beyond,” Rivera-Mills said. “I am enthusiastic about the opportunities. Our action-based agenda will promote economic, political, physical and educational well-being and development.”

Rivera-Mills has been on the OSU faculty since 2007, and has mentored Latino students and been involved with the university’s internationalization and transnational efforts, as well as been a leader in student engagement and global learning initiatives. She specializes in Spanish language maintenance and loss, sociolinguistics, and Spanish as a first and second language.

CL@SE will be affiliated with both the OSU Provost’s Office and the Research Office, officials say.

“Our recently developed research agenda emphasizes relevance, integration, collaboration and leadership,” said Richard Spinrad, OSU’s vice president for research. “Its principles support team-based research, student involvement, partnership with communities, and transdisciplinary research. CL@SE has at its core all of these principles and reflects the values of the OSU research community.”

Scott Reed, OSU’s vice provost for University Outreach and Engagement, said Rivera-Mills is ideally suited to direct the launch of the new center. “The advancement of social justice is among the important things that will be fostered with Susana’s able leadership,” Reed said.

CL@SE will collaborate with several units on campus, especially the colleges of liberal arts, science and education, and Outreach and Engagement.

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Rick Spinrad, 541-737-0662

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Susana Rivera-Mills
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