OREGON STATE UNIVERSITY

college of earth

Scientists document first consumption of abundant life form, Archaea

CORVALLIS, Ore. – A team of scientists has documented for the first time that animals can and do consume Archaea – a type of single-celled microorganism thought to be among the most abundant life forms on Earth.

Archaea that consume the greenhouse gas methane were in turn eaten by worms living at deep-sea cold seeps off Costa Rica and the West Coast of the United States. Archaea perform many key ecosystem services including being involved with nitrogen cycling, and they are known to be the main mechanism by which marine methane is kept out of the atmosphere.

The finding of this new study adds a wrinkle to scientific understand of greenhouse gas cycles. Results of the study, which was funded by the National Science Foundation, have been published online in the International Society for Microbial Ecology Journal, a subsidiary of the journal Nature.

“This opens up a new avenue of research,” said Andrew Thurber, a post-doctoral researcher at Oregon State University and lead author on the study. “Archaea weren’t even discovered until 1977, and were thought to be rare and unimportant, but we are beginning to realize that they not only are abundant, but they have roles that have not fully been appreciated.”

Archaea are considered one of the three “domains of life” on Earth, along with bacteria and eukaryota (plants and animals). Despite their abundance, no member of the Archaea domain has been known to be part of a food web.

One of the basic questions scientists have asked is whether this life form could act as a food source for animals. To answer this, the researchers performed a laboratory study during which they fed two types of Archaea to the worms, as well as meals of bacteria, spinach or rice, and the worms thrived on all of the food sources, growing at the same rate.

“That showed us that Archaea can be a viable food source for at least some animals,” Thurber pointed out. 

Thurber and his colleagues initially were looking at biological life forms at a cold seep in the deep ocean off Costa Rica, when they opened up a rock and found worms living within the crevices. They found that the worms had been feeding on Archaea, which had, in turn, been consuming methane. They were able to trace the isotopic signature of the methane from the Archaea to the worms.

From what they learned from the Costa Rican study, the scientists also discovered that worms of the same family as those found in the rocks consume methane-munching Archaea at cold seeps off northern California and at Hydrate Ridge off the central Oregon coast, west of Newport. The researchers think the family of worms, the Dorvilleids, uses its teeth to scrape the Archaea off rocks.

The consumption of Archaea by grazers, a process coined “archivory” by Thurber in the article, is particularly interesting because the only way it could be documented was by tracing the isotopic biomarkers from the methane. When the researchers attempted to trace consumption of Archaea through lipid types and other mechanisms, they failed because the chemicals and proteins broke down within the worms.

“It could be that many other animals are consuming Archaea but we haven’t been able to detect it,” pointed out Thurber, who did much of the research as a doctoral candidate at the Scripps Institution of Oceanography.  “We still haven’t found the right technique to identify animals that eat Archaea that don’t rely on methane, but now we know to look.

“Hopefully, this will open up a lot of new research,” Thurber added, “and provide a greater understanding of how the world works.”

The deep ocean sequesters vast amounts of methane and researchers believe that Archaea consume a majority of it before it reaches the water column. The role of Archaea consumers now will have to be taken into effect, Thurber said.

“We’re not yet sure of the implications,” said Thurber, who is affiliated with OSU’s College of Earth, Ocean, and Atmospheric Sciences. “But Archaea are found in many different places, from estuaries to the deep sea, so it is possible that they fit into food webs beyond the cold seeps where we documented the process.”

Other authors on the paper include Lisa Levin of Scripps, and Victoria Orphan and Jeffrey Marlow of the California Institute of Technology.

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Andrew Thurber, 541-737-8251

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Archivory worm

Archaea-eating worm

 

Archaea rock

Rock where worms, Archaea were found

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

Verena Tunnicliffe to deliver OSU “Vents” lecture on March 1

CORVALLIS, Ore. – Verena Tunnicliffe, a University of Victoria marine ecologist and explorer of deep-sea environments, will deliver a free public lecture at Oregon State University on Thursday, March 1, to commemorate OSU’s Hydrothermal Vents Discovery Day.

Tunnicliffe’s lecture is sponsored by the “Frontiers of Science” lecture series.

“Beyond the Mid-Ocean Ridge: Hydrothermalism and Vent Communities on Volcanic Arcs of the Western Pacific,” will provide a biologist’s viewpoint of hydrothermal eruptions in a different part of the ocean than on ridge crests, which are more widely known. Her talk begins at 4 p.m. in Gilfillan Auditorium on the OSU campus.

The lecture marks the 35th anniversary of the discovery of hydrothermal vents on a research cruise to the Galapagos, led by OSU scientist Jack Corliss. That discovery revealed an entire colony of marine creatures – many of which had never been seen before – and launched a new era of oceanographic exploration.

As more hydrothermal vents were documented beyond the ridge crest systems throughout the world oceans, scientists have discovered life-nurturing conditions in volcanic arcs and seamounts that have their own geophysical, chemical and biological features. Life at volcanoes ranges from shallow-water “smokers” to liquid carbon-dioxide vents and pools of molten sulfur.

These will be a focus of the presentation by Tunnicliffe, which is sponsored by OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Tunnicliffe has worked closely with researchers at OSU’s Hatfield Marine Science Center, including Bill Chadwick and Susan Merle, on explorations of undersea volcanoes and associated hydrothermal vent colonies. She is a principal investigator with the Canadian Healthy Ocean Network, as well as the director of Ocean Network Canada’s VENUS (Victoria Experimental Network Under the Sea) cabled observatory.

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Bob Collier, 541-737-4367

"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

OSU scientist receives prestigious Sloan Research Fellowship

CORVALLIS, Ore. – Angelicque “Angel” White, an oceanographer from Oregon State University, has received a 2012 Sloan Research Fellowship from the Alfred P. Sloan Foundation.

Fellowships were awarded to 126 top young researchers in the United States and Canada. Awarded annually since 1955, the fellowships are given to early-career scientists and scholars identified as rising stars and the next generation of scientific leaders.

“Today’s Sloan Research Fellows are tomorrow’s Nobel Prize winners, said Paul L. Joskow, president of the Alfred P. Sloan Foundation.

Sloan Fellowships historically have been awarded in seven fields, including chemistry, computer science, economics, mathematics, evolutionary and computational molecular biology, neuroscience, and physics. This year, the foundation expanded to include ocean sciences and awarded eight fellowships in that field, including the one to White.

White is an assistant professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences whose work focuses on ocean productivity and phytoplankton physiology. She is a member of the National Science Foundation-funded Center for Microbial Oceanography: Research and Education (C-MORE), and has been active in a collaborative project to monitor harmful algal blooms off the Oregon coast.

She also has studied the Pacific Ocean “garbage patch,” a huge collection of plastic trapped in a gyre off the West Coast, which she has described as problematic, but exaggerated in scale in many media reports.

Sloan Fellowships provide $50,000 over two years for equipment, technical assistance, professional travel, trainee support and other activities supporting the fellow’s research.

A list of the 2012 recipients is available at: www.sloan.org/fellowships/page/21

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Angel White, 541-737-6397

Scientists discover reason for Mt. Hood’s non-explosive nature

CORVALLIS, Ore. – For a half-million years, Mount Hood has towered over the landscape, but unlike some of its cousins in Oregon’s Cascade Mountains and many other volcanoes around the Pacific “Rim of Fire,” it doesn’t have a history of large, explosive eruptions.

Now a team of scientists has found out why.

In new research just published online in the Journal of Volcanology and Geothermal Research, lead author Alison Koleszar of Oregon State University and her colleagues describe how mixing of magma deep beneath Mount Hood appears to have prevented it from blowing its top over the millennia. Their research has been funded primarily by the National Science Foundation.

Volcanic eruptions are usually described as “high-explosivity” or “low-explosivity” events, said Koleszar, who is a post-doctoral researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences. Many volcanoes have experienced both. High-explosivity events are often referred to as Plinian eruptions, named after Pliny the Younger who described the eruption of Mount Vesuvius that destroyed the Roman city of Pompeii in AD 79. During these eruptions, large amounts of magma are ejected into the atmosphere at high velocity – such as Mount St. Helens in 1980 and Mount Pinatubo in 1992.

But studies of the rocks around Mount Hood show that the volcano has never experienced a Plinian eruption despite having similar chemical magma composition and gas contents as other volcanoes that have gone through these violent episodes.

The reason, Koleszar says, is that eruptions at Mount Hood appear to be preceded by episodes of intense mixing between magmas of different temperatures. Hot magma rises from deep below Mount Hood and mixes with the cooler magma that underlies the volcano. Heat from the deeper, hotter magma increases the temperature and lowers the viscosity of the magma that eventually erupts.

Instead of exploding, a la Mount St. Helens, magma at Mount Hood oozes out the top of the volcano and piles up to form a lava dome.

“If you take a straw and blow bubbles into a glass of milk, it will bubble up and allow the pressure to escape,” Koleszar said. “But if you blow bubbles into a thick milkshake you need more pressure and it essentially ‘erupts’ with more force as bits of milkshake get thrown into the air. Add a little heat to the milkshake, though, and it thins out and bubbles gently when you blow into it, more like the glass of milk.

"That what Mount Hood has been doing – heating things up enough to avoid a major explosion.”

What happens instead of an explosive eruption is more of a hiccup, according to Adam Kent, an OSU volcanologist who was Koleszar’s major professor when she earned her doctorate. The researchers analyzed three eruptive events on Mount Hood from the past 30,000 years, the last of which occurred about 220 years ago. These low-explosivity events resulted in the formation of lava domes near Mount Hood’s summit. Crater Rock, on the south side of the mountain, is a remnant of one of these lava domes.

“Instead of an explosion, it would be more like squeezing a tube of toothpaste,” said Kent, who also is an author on the study. “Lava piles up to form a dome; the dome eventually collapses under its own weight and forms a hot landslide that travels down the side of the volcano. In contrast, during a Plinian event such as the kind seen at other volcanoes, ash and rock are blown high into the air and distributed all over.”

Although Mount Hood lacks an explosive history, it doesn’t mean the 11,240-foot peak is completely docile. Collapses of the lava dome at Crater Rock about 1,500 years ago, and again 220 years ago, sent scalding landslides of hot lava blocks down the south side of the volcano, Kent pointed out.

“These types of events have dominated the eruptive activity at Mount Hood for the past 30,000 years,” Kent said. “The other danger is from lahars, which are major mudflows that stream down the side of the mountain at some 50 miles-an-hour, with the consistency of cement. They result when heat from the magma melts snow and mixes it with the volcanic ash and rock.

“Lahars probably accompany most eruptions of the volcano, and can even occur between eruptions after heavy rains or rapid snowmelt,” Kent added. “And they can go quite a ways – all the way to the Columbia River, for instance.”

Koleszar said few other volcanoes around the world act quite like Mt. Hood. It is, she said, a poster child for low-explosivity eruptions.

“Mount Hood is really cool because it is such a model for one extreme of volcano behavior,” Koleszar pointed out. “It may not have the colorful history of Mount Mazama or St. Helens, but it has its own niche among volcanoes – and now we better understand why it behaves the way it does.”

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Alison Koleszar, 541-737-1232

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Mount Hood

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

Oregon preparing for debris from Japanese tsunami

CORVALLIS, Ore. – As the one-year anniversary of the devastating March 11, 2011, Japanese earthquake approaches, and debris from the ensuing tsunami moves closer to the West Coast, a group of Oregon agencies, university scientists, political staff, non-governmental organizations and others is preparing for its arrival.

This week, the group held a conference call to review Oregon’s response to the potential arrival of the debris and to chart a communication strategy to educate West Coast residents about what may happen. Questions directed at state and county leaders, Oregon State University Extension experts, the OSU Hatfield Marine Science Center and others are increasing daily.

When will the debris arrive? Where will it land? Is there any danger of radioactivity? What shall we do if we find something?

Jack Barth, an OSU oceanographer and expert in ocean currents, said the debris is still months away from arriving on the West Coast, though it is possible that strong winds may push some floating items that rise high above the surface more quickly to the North American shore. Floats from Japanese fishing nets have washed up on the Washington coast in recent weeks, but those haven’t been tied directly to the tsunami.

“Material from Asia washes up on the West Coast routinely,” Barth said. “It doesn’t necessarily mean it is tsunami-related. A Russian ship discovered a small Japanese fishing boat in the waters north of Hawaii in October that was definitively tied to the tsunami – and it was about where we thought it should be, given the currents.” NOAA reports no radiation was detected on the fishing boat.

Barth, who is the associate dean of OSU’s College of Earth, Ocean, and Atmospheric Sciences, has met with U.S. Sen. Ron Wyden, and representatives of the National Oceanic and Atmospheric Administration (NOAA) and various Oregon agencies and organizations in recent weeks. He said it is difficult to calculate how much debris remains in the ocean, and what exactly will arrive on our shore.

When and how it arrives is a matter of ocean physics, he pointed out.

“Much of the debris generated from the earthquake and tsunami has or will become waterlogged, weighed down with barnacles or other organisms, and sink,” Barth said. “A large fraction of it will be diverted south into the ‘Garbage Patch’ between Hawaii and the West Coast, and may circulate in that gyre.

“What remains should arrive here at the end of 2012, or the beginning of 2013,” he added. “If it arrives in the fall and winter, it will get pushed up north by the currents to Washington, British Columbia and even Alaska. Debris arriving in late spring and summer will hit Oregon and be swept south into California waters.”

What does arrive is unlikely to be dangerous, according to Kathryn Higley, professor and head of the Department of Nuclear Engineering and Radiation Health Physics at OSU. Higley was one of the most widely cited scientists following the incidents at Japan’s Dai-ichi nuclear plant after the earthquake. She says the lag time between the tsunami and the nuclear incident, coupled with the vastness of the ocean, makes it unlikely that the debris will carry any danger from radiation.

“The major air and water discharges of radioactive material from the Dai-ichi plants occurred a few days after the debris field was created by the tsunami,” Higley pointed out. “So the debris field was spread out at the time the discharges occurred. This would have diluted the radiological impact.

“Secondly, wind, rain and salt spray have been pummeling this material for months,” she said. “The key radionuclides are composed of iodine and cesium – which are chemically a lot like chlorine and sodium. Most of the iodine has gone because of radioactive decay. The radioactive cesium, to a great extent, will be washed off and diluted in the surrounding ocean.

“Therefore, while we may be able to detect trace amounts of radioactive material on this debris, it’s really unlikely that there will be any substantial radiation risk,” Higley said.

Staci Simonich, an OSU professor of Environmental and Molecular Toxicology, has been monitoring the air for emissions from Japan and said that since last April (2011), radiation levels were at “background.”

“Those are naturally occurring levels – at concentrations far below standards for public safety,” she said.

NOAA is monitoring the debris from a national perspective and has a website that can educate the public and keep interested persons updated. It is at http://marinedebris.noaa.gov/.  The agency suggests that beachcombers and others who find material they think may be from Japan report it at disasterdebris@noaa.gov – and use common sense.

They write: “As with any outdoors activity, it is important to follow common sense and put safety first. Avoid picking up debris that you are not well-equipped and trained to handle. For example, be careful of sharp objects that could cut yours hands; avoid picking up sealed containers of chemicals – they may crack or break and spill the content on you; likewise, report any full drum on the beach, and avoid handling it yourself. If you are uncomfortable handling any debris item, leave it where it is.”

Jamie Doyle, an OSU Extension Sea Grant specialist in Coos and Curry counties, said a variety of Oregon agencies and non-governmental organizations are beginning to plan for various response scenarios. As Oregon’s planning progresses, she says, “expect more information for the public.”

“One other concern is what should happen if someone finds any personal effects,” Doyle said. “A lot of people lost their lives, and many people still have family members who are missing. We need to be sensitive to the possibility of finding something that may be of personal significance to someone in Japan.”

Tomoko Dodo, from the Consulate General of Japan’s office in Seattle, has asked that persons finding something that could be considered a personal “keepsake” for a survivor report it to local authorities, or the consulate in Seattle at 206-682-9107.

Patrick Corcoran, an OSU Extension Sea Grant specialist for the North Coast, said the focus thus far has been on research and “building the capacity to respond” to the arrival of the debris. Specific information on Oregon resources and contacts will be forthcoming, he said.

Among the other organizations working on planning Oregon Surfrider Foundation, Stop Oregon Litter and Vandalism (SOLV), Coast Watch, Oregon Emergency Management, Oregon Public Health Division; West Coast Governors’ Alliance; Oregon Parks and Recreation Department;  Oregon Refuse and Recycling Association; Oregon Fishermen’s Cable Committee; Office of U.S. Sen. Ron Wyden; Office of Oregon Gov. John Kitzhaber; Washed Ashore; Oregon Department of Environmental Quality; Oregon Department of Land Conservation and Development; U.S. Coast Guard; and Western Oregon Waste.

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Jack Barth, 541-737-1607

OSU to retire one research vessel, take over operation of another

NEWPORT, Ore. – For more than 35 years, the Oregon State University research vessel Wecoma has carried scientists out of Newport to sea to learn about fisheries, climate change, undersea earthquakes and volcanoes, tsunamis, marine dead zones and other scientific issues.

The R/V Wecoma made its last official voyage in November, taking a research team off the Northwest coast to map the Cascadia Subduction Zone. And now the venerable vessel is heading into retirement.

In its place, another ship in the University National Oceanographic Laboratory System fleet, the 35-year-old Oceanus, will support scientific research in the northeast Pacific Ocean. Operated by the Woods Hole Oceanographic Institution, Oceanus was also scheduled to be retired but will arrive in Newport, Ore., in February after making the long trek from the East Coast.

This changing of the ships is somewhat unusual, according to Mark Abbott, dean of the College of Earth, Ocean, and Atmospheric Sciences at OSU.

Abbott approached the National Science Foundation about a rapid analysis of the two ships to see which one would be more cost-effective to operate over the next several years. A team of technicians returned the verdict – a strong recommendation for the 177-foot Oceanus.

“During the analysis, we also discovered some problems with the Wecoma’s hull, as well as corrosion that would have required costly dry-docking,” Abbott pointed out. “The combination of that discovery and the overall report prompted us to send a letter of interest to the NSF to take over the Oceanus and retire Wecoma.”

“There are a few differences in science capabilities,” Abbott added, “but Oceanus is very capable and will be more cost-effective to operate over the next five to 10 years, at which point we hope to have a new ship.”

OSU has operated large research vessels since 1964, and has had the Wecoma since 1975. The fate of the ship is unclear – after its retirement from the University National Oceanographic Laboratory System fleet, OSU and National Science Foundation leaders will review options for disposition.

Oregon State is an active member of UNOLS, a consortium of 60 academic research institutions that operate 16 vessels around the country, according to Demian Bailey, OSU’s marine superintendent. Wecoma and Oceanus are owned by the National Science Foundation and support research projects funded primarily by NSF and the U.S. Navy.

Both ships will be docked at OSU’s Hatfield Marine Science Center in Newport, adjacent to a new facility built for the National Oceanic and Atmospheric Administration to maintain its Pacific fleet. That fleet supports monitoring and research needs of NOAA.

OSU also operates the 54-foot Elakha and 85-foot Pacific Storm, which are used primarily for near-shore research.

Oceanus will leave Woods Hole in late January, sail through the Panama Canal and arrive in Newport in late February. It will be ready to support the first OSU research cruise in late March.

A retirement celebration for the Wecoma will be held at the Hatfield Marine Science Center in March.

The Wecoma:

  • Built in 1975, and overhauled in 1995;
  • 184.5 feet long
  • Cruising speed: 12 knots
  • Range: 7,200 nautical miles
  • Endurance: 30 days
  • Capacity: 13 crew members and 18 scientists

The Oceanus:

  • Built in 1975, and overhauled in 1994;
  • 177 feet long
  • Cruising speed: 11 knots
  • Range: 7,000 nautical miles
  • Endurance: 30 days
  • Capacity: 12 crew members and 14 scientists

History of OSU Research Vessels

  • 1964 – The Department of Oceanography commissions the 180-foot Yaquina
  • 1968 – The Department of Oceanography commissions the 80-foot Cayuse
  • 1975 – The School of Oceanography commissions the 184-foot Wecoma
  • 2000 – The College of Oceanic and Atmospheric Sciences commissions the 54-foot Elakha
  • 2012 – The College of Earth, Ocean, and Atmospheric Sciences takes over operation of the 177-foot Oceanus.
Media Contact: 
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Mark Abbott, 541-737-5195

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Satellite imagery detects thermal “uplift” signal of underground nuclear tests

The study this release is based on is available at OSU Scholars Archive: http://ir.library.oregonstate.edu/xmlui/handle/1957/26406

CORVALLIS, Ore. – A new analysis of satellite data from the late 1990s documents for the first time the “uplift” of ground above a site of underground nuclear testing, providing researchers a potential new tool for analyzing the strength of detonation.

The study has just been published in Geophysical Research Letters.

Lead author Paul Vincent, a geophysicist at Oregon State University, cautions that the findings won’t lead to dramatic new ability to detect secret nuclear explosions because of the time lag between the test and the uplift signature, as well as geophysical requirements of the underlying terrain. However, he said, it does “provide another forensic tool for evaluation, especially for the potential explosive yield estimates.”

“In the past, satellites have been used to look at surface subsidence as a signal for nuclear testing,” said Vincent, an associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “This is the first time uplift of the ground has correlated to a nuclear test site. The conditions have to be just right and this won’t work in every location.

“But it is rather interesting,” he added. “It took four years for the source of the uplift signal – a thermal groundwater plume – to reach the surface.”

The focus of the study was Lop Nor, a nuclear testing site in China where three tests were conducted – May 21, 1992; May 15, 1995; and Aug. 17, 1995. Vincent and his colleagues analyzed interferometric synthetic aperture radar (InSAR) images from 1996-99 and detected a change in the surface beginning four years after the tests.

Though the uplift was less than two inches, it corresponds to known surface locations above past tests within the Lop Nor test site.

From past studies, the researchers knew that heat from underground detonation of nuclear devices propagates slowly toward the surface. At most sites – including the Nevada National Security Site – that heat signal dissipates laterally when it reaches the water table, which is usually deep beneath the surface.

At Lop Nor, however, the water table is only about three meters below the surface, and the heated groundwater plume took four years to reach that high, lifting the ground above the detonation site slightly – but enough to be detected through InSAR images.

Lop Nor also is characterized by a hard granite subsurface, which helps pipe the heated water vertically and prevents the subsidence frequently found at other testing sites.

A past study by Vincent, published in 2003, first shed light on how subsidence can manifest itself in different ways – from the force of the explosion creating a crater, to more subtle effects of “chimneying,” in which the blast opens up a chimney of sorts and draws material downward, creating a dimple at the ground surface.

Before joining the OSU faculty in 2007, Vincent spent several years as a physicist at the Lawrence Livermore National Laboratory.

Vincent said the analysis of nuclear explosions has become a specialized field. Seismology technology can provide an initial estimate of the energy of the explosion, but that data is only good if the seismic waves accurately reflect coupling to the connecting ground in a natural way, he explained. Efforts are sometimes made to “decouple” the explosive device from the ground by creating specializing testing chambers that can give off a false signal, potentially masking the true power of a test.

“Subsidence data combined with seismic data have helped narrow the margin of error in estimating the explosive yield,” Vincent noted, “and now there is the potential to use test-related thermal expansion as another forensic tool.”

Co-authors on the paper with Vincent include Sean Buckley of the Jet Propulsion Laboratory, Dochul Yang, the University of Texas-Austin, and Steve Carle, of Lawrence Livermore National Laboratory.

Media Contact: 
Source: 

Paul Vincent, 541-737-9176