OREGON STATE UNIVERSITY

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SAR11, oceans’ most abundant organism, has ability to create methane

CORVALLIS, Ore. – The oxygen-rich surface waters of the world’s major oceans are supersaturated with methane – a powerful greenhouse gas that is roughly 20 times more potent than carbon dioxide – yet little is known about the source of this methane.

Now a new study by researchers at Oregon State University demonstrates the ability of some strains of the oceans’ most abundant organism – SAR11 – to generate methane as a byproduct of breaking down a compound for its phosphorus.

Results of the study are being published this week in Nature Communications. It was funded by the National Science Foundation and the Gordon and Betty Moore Foundation.

“Anaerobic methane biogenesis was the only process known to produce methane in the oceans and that requires environments with very low levels of oxygen,” said Angelicque “Angel” White, a researcher in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study. “In the vast central gyres of the Pacific and Atlantic oceans, the surface waters have lots of oxygen from mixing with the atmosphere – and yet they also have lots of methane, hence the term ‘marine methane paradox.’

“We’ve now learned that certain strains of SAR11, when starved for phosphorus, turn to a compound known as methylphosphonic acid,” White added. “The organisms produce enzymes that can break this compound apart, freeing up phosphorus that can be used for growth – and leaving methane behind.”

The discovery is an important piece of the puzzle in understanding the Earth’s methane cycle, scientists say. It builds on a series of studies conducted by researchers from several institutions around the world over the past several years.

Previous research has shown that adding methylphosphonic acid, or MPn, to seawater produces methane, though no one knew exactly how. Then a laboratory study led by David Karl of the University of Hawaii and OSU’s White found that an organism called Trichodesmium could break down MPn and thus it could be a potential source of phosphorus, which is a critical mineral essential to every living organism.

However, Trichodesmium are rare in the marine environment and unlikely to be the only source for vast methane deposits in the surface waters.

So White turned to Steve Giovannoni, a distinguished professor of microbiology at OSU, who not only maintains the world’s largest bank of SAR11 strains, but who also discovered and identified SAR11 in 1990. In a series of experiments, White, Giovannoni, and graduate students Paul Carini and Emily Campbell tested the capacity of different SAR11 strains to consume MPn and cleave off methane.

“We found that some did produce a methane byproduct, and some didn’t,” White said. “Just as some humans have a different capacity for breaking down compounds for nutrition than others, so do these organisms. The bottom line is that this shows phosphate-starved bacterioplankton have the capability of producing methane and doing so in oxygen-rich waters.”

SAR11 is the smallest free-living cell known and also has the smallest genome, or genetic structure, of any independent cell. Yet it dominates life in the oceans, thrives where most other cells would die, and plays a huge role in the cycling of carbon on Earth.

These bacteria are so dominant that their combined weight exceeds that of all the fish in the world's oceans, scientists say. In a marine environment that's low in nutrients and other resources, they are able to survive and replicate in extraordinary numbers – a milliliter of seawater, for instance, might contain 500,000 of these cells.

"The ocean is a competitive environment and these bacteria apparently won the race," said Giovannoni, a professor in OSU’s College of Science. "Our analysis of the SAR11 genome indicates that they became the dominant life form in the oceans largely by being the simplest.”

“Their ability to cleave off methane is an interesting finding because it provides a partial explanation for why methane is so abundant in the high-oxygen waters of the mid-ocean regions,” Giovannoni added. “Just how much they contribute to the methane budget still needs to be determined.”

Since the discovery of SAR11, scientists have been interested in their role in the Earth’s carbon budget. Now their possible implication in methane creation gives the study of these bacteria new importance.

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Angel White, 541-737-6397; awhite@coas.oregonstate.edu; Steve Giovannoni, 541-737-1835, steve.giovannoni@oregonstate.edu

Study links Greenland ice sheet collapse, sea level rise 400,000 years ago

CORVALLIS, Ore. – A new study suggests that a warming period more than 400,000 years ago pushed the Greenland ice sheet past its stability threshold, resulting in a nearly complete deglaciation of southern Greenland and raising global sea levels some 4-6 meters.

The study is one of the first to zero in on how the vast Greenland ice sheet responded to warmer temperatures during that period, which were caused by changes in the Earth’s orbit around the sun.

Results of the study, which was funded by the National Science Foundation, are being published this week in the journal Nature.

“The climate 400,000 years ago was not that much different than what we see today, or at least what is predicted for the end of the century,” said Anders Carlson, an associate professor at Oregon State University and co-author on the study. “The forcing was different, but what is important is that the region crossed the threshold allowing the southern portion of the ice sheet to all but disappear.

“This may give us a better sense of what may happen in the future as temperatures continue rising,” Carlson added.

Few reliable models and little proxy data exist to document the extent of the Greenland ice sheet loss during a period known as the Marine Isotope Stage 11. This was an exceptionally long warm period between ice ages that resulted in a global sea level rise of about 6-13 meters above present. However, scientists have been unsure of how much sea level rise could be attributed to Greenland, and how much may have resulted from the melting of Antarctic ice sheets or other causes.

To find the answer, the researchers examined sediment cores collected off the coast of Greenland from what is called the Eirik Drift. During several years of research, they sampled the chemistry of the glacial stream sediment on the island and discovered that different parts of Greenland have unique chemical features. During the presence of ice sheets, the sediments are scraped off and carried into the water where they are deposited in the Eirik Drift.

“Each terrain has a distinct fingerprint,” Carlson noted. “They also have different tectonic histories and so changes between the terrains allow us to predict how old the sediments are, as well as where they came from. The sediments are only deposited when there is significant ice to erode the terrain. The absence of terrestrial deposits in the sediment suggests the absence of ice.

“Not only can we estimate how much ice there was,” he added, “but the isotopic signature can tell us where ice was present, or from where it was missing.”

This first “ice sheet tracer” utilizes strontium, lead and neodymium isotopes to track the terrestrial chemistry.

The researchers’ analysis of the scope of the ice loss suggests that deglaciation in southern Greenland 400,000 years ago would have accounted for at least four meters – and possibly up to six meters – of global sea level rise. Other studies have shown, however, that sea levels during that period were at least six meters above present, and may have been as much as 13 meters higher.

Carlson said the ice sheet loss likely went beyond the southern edges of Greenland, though not all the way to the center, which has not been ice-free for at least one million years.

In their Nature article, the researchers contrasted the events of Marine Isotope Stage 11 with another warming period that occurred about 125,000 years ago and resulted in a sea level rise of 5-10 meters. Their analysis of the sediment record suggests that not as much of the Greenland ice sheet was lost – in fact, only enough to contribute to a sea level rise of less than 2.5 meters.

“However, other studies have shown that Antarctica may have been unstable at the time and melting there may have made up the difference,” Carlson pointed out.

The researchers say the discovery of an ice sheet tracer that can be documented through sediment core analysis is a major step to understanding the history of ice sheets in Greenland – and their impact on global climate and sea level changes. They acknowledge the need for more widespread coring data and temperature reconstructions.

“This is the first step toward more complete knowledge of the ice history,” Carlson said, “but it is an important one.”

Lead author on the Nature study is Alberto Reyes, who worked as a postdoctoral researcher for Carlson when both were at the University of Wisconsin-Madison. Carlson is now on the faculty in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

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Anders Carlson, 541-737-3625; acarlson@coas.oregonstate.edu

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Antarctic Ice Sheet unstable at end of last ice age

CORVALLIS, Ore. – A new study has found that the Antarctic Ice Sheet began melting about 5,000 years earlier than previously thought coming out of the last ice age – and that shrinkage of the vast ice sheet accelerated during eight distinct episodes, causing rapid sea level rise.

The international study, funded in part by the National Science Foundation, is particularly important coming on the heels of recent studies that suggest destabilization of part of the West Antarctic Ice Sheet has begun.

Results of this latest study are being published this week in the journal Nature. It was conducted by researchers at University of Cologne, Oregon State University, the Alfred-Wegener-Institute, University of Hawaii at Manoa, University of Lapland, University of New South Wales, and University of Bonn.

The researchers examined two sediment cores from the Scotia Sea between Antarctica and South America that contained “iceberg-rafted debris” that had been scraped off Antarctica by moving ice and deposited via icebergs into the sea. As the icebergs melted, they dropped the minerals into the seafloor sediments, giving scientists a glimpse at the past behavior of the Antarctic Ice Sheet.

Periods of rapid increases in iceberg-rafted debris suggest that more icebergs were being released by the Antarctic Ice Sheet. The researchers discovered increased amounts of debris during eight separate episodes beginning as early as 20,000 years ago, and continuing until 9,000 years ago.

The melting of the Antarctic Ice Sheet wasn’t thought to have started, however, until 14,000 years ago.

“Conventional thinking based on past research is that the Antarctic Ice Sheet has been relatively stable since the last ice age, that it began to melt relatively late during the deglaciation process, and that its decline was slow and steady until it reached its present size,” said lead author Michael Weber, a scientist from the University of Cologne in Germany.

“The sediment record suggests a different pattern – one that is more episodic and suggests that parts of the ice sheet repeatedly became unstable during the last deglaciation,” Weber added.

The research also provides the first solid evidence that the Antarctic Ice Sheet contributed to what is known as meltwater pulse 1A, a period of very rapid sea level rise that began some 14,500 years ago, according to Peter Clark, an Oregon State University paleoclimatologist and co-author on the study.

The largest of the eight episodic pulses outlined in the new Nature study coincides with meltwater pulse 1A.

“During that time, the sea level on a global basis rose about 50 feet in just 350 years – or about 20 times faster than sea level rise over the last century,” noted Clark, a professor in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. “We don’t yet know what triggered these eight episodes or pulses, but it appears that once the melting of the ice sheet began it was amplified by physical processes.”

The researchers suspect that a feedback mechanism may have accelerated the melting, possibly by changing ocean circulation that brought warmer water to the Antarctic subsurface, according to co-author Axel Timmermann, a climate researcher at the University of Hawaii at Manoa.

“This positive feedback is a perfect recipe for rapid sea level rise,” Timmermann said.

Some 9,000 years ago, the episodic pulses of melting stopped, the researchers say.

“Just as we are unsure of what triggered these eight pulses,” Clark said, “we don’t know why they stopped. Perhaps the sheet ran out of ice that was vulnerable to the physical changes that were taking place. However, our new results suggest that the Antarctic Ice Sheet is more unstable than previously considered.”

Today, the annual calving of icebergs from Antarctic represents more than half of the annual loss of mass of the Antarctic Ice Sheet – an estimated 1,300 to 2,000 gigatons (a gigaton is a billion tons). Some of these giant icebergs are longer than 18 kilometers.

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Peter Clark, 541-740-5237

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White House appoints OSU’s Spinrad as NOAA’s chief scientist

CORVALLIS, Ore. – The White House announced today the appointment of Richard (Rick) Spinrad, the vice president for research at Oregon State University since July 2010, as chief scientist for the National Oceanic and Atmospheric Administration.

Spinrad will resign from his position as vice president and take a leave of absence from the Oregon State faculty to accept the NOAA appointment, which begins in July. He is a professor in the College of Earth, Ocean, and Atmospheric Sciences.

As NOAA’s chief scientist, Spinrad will help drive the policy and program direction for all science and technology priorities at the agency and advise NOAA Administrator Kathy Sullivan and agency program leaders on research matters.

“I am honored to be appointed to this position at such a critical time,” Spinrad said. “The issues that NOAA is addressing relate to natural hazards, resource management and the optimal application of research to solve problems. Being asked to help guide the agency’s scientific agenda is a humbling and exciting opportunity.”

OSU President Edward J. Ray praised Spinrad, and pointed to the long list of Oregon State faculty and administrators who recently have held high-ranking federal appointments, including former NOAA Administrator Jane Lubchenco and others.

“Rick Spinrad has provided exceptional leadership to the university’s research enterprise,” said OSU President Edward J. Ray. “He has successfully increased our research partnerships with industry, spearheaded the drive for a marine studies campus in Newport, and helped OSU secure a major grant to design and oversee the construction of as many as three new ships for the United States research fleet.

“We will miss his many contributions, but we know that he will make an outstanding addition to the NOAA administration.”

Under Spinrad’s leadership, the last fiscal year was OSU’s best ever in technology licensing as the university signed 88 new licenses with organizations in the fields of information technology, agriculture, industrial materials, biotechnology, forest products, healthy aging and manufacturing. OSU also received a record $7.7 million in licensing and royalty income, and research funding from the private sector reached $36 million – a 65 percent increase over the last five years.

A key component of OSU’s growth in industry partnerships under Spinrad was the launch of a new initiative in January 2013 called the Oregon State University Advantage, which is designed to boost the university’s impact on job creation and economic progress in Oregon and beyond. The program has increased access by private industry to OSU’s faculty and researchers and allows companies to take better advantage of the university’s unique capabilities.

Spinrad also played an integral role in the launch of the Regional Accelerator and Innovation Network known as Oregon RAIN and the selection of OSU – along with public and private partners in Alaska and Hawaii – to run a center to investigate the civilian use of unmanned aerial vehicles.

He also was a member of the Corvallis Economic Development Commission.

“It was a difficult decision to leave OSU at this time,” Spinrad said. “Our success in research of late and the exciting prospects for the university’s future are testimony to the extraordinary skills and capabilities of our faculty, staff, students and administrators. I will watch OSU’s continued growth with a sense of confidence and pride in the university community.”

Before coming to OSU, Spinrad was assistant administrator for research at NOAA. He also has been the research director for the U.S. Navy; taught oceanography at two universities; directed a major national non-profit organization; was president of a private company; and worked as a research scientist.

Spinrad received his master’s (1978) and doctoral (1982) degrees in oceanography from OSU.

An interim vice president for OSU research will be appointed in the near future.

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Rick Spinrad, 541-737-0662; rick.spinrad@oregonstate.edu; Steve Clark, 503-502-8217; steve.clark@oregonstate.edu

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Study finds only trace levels of radiation from Fukushima in albacore

CORVALLIS, Ore. – Albacore tuna caught off the Oregon shore after the Fukushima Daiichi power station in Japan was destroyed in a 2011 earthquake had slightly elevated levels of radioactivity but the increase has been minute, according to a newly published study.

In fact, you would have to consume more than 700,000 pounds of the fish with the highest radioactive level – just to match the amount of radiation the average person is annually exposed to in everyday life through cosmic rays, the air, the ground, X-rays and other sources, the authors say.

Results of the study are being published in the journal Environmental Science and Technology.

“You can’t say there is absolutely zero risk because any radiation is assumed to carry at least some small risk,” said Delvan Neville, a graduate research assistant in the Department of Nuclear Engineering and Radiation Health Physics at Oregon State University and lead author on the study. “But these trace levels are too small to be a realistic concern.

“A year of eating albacore with these cesium traces is about the same dose of radiation as you get from spending 23 seconds in a stuffy basement from radon gas, or sleeping next to your spouse for 40 nights from the natural potassium-40 in their body,” he added. “It’s just not much at all.”

In their study, the researchers examined a total of 26 Pacific albacore caught off the coast between 2008 and 2012 to give them a comparison between pre-Fuskushima and post-Fukushima radiation levels. They discovered that levels of specific radioactive isotopes did increase, but at the most extreme level, they only tripled – a measurement that is only 0.1 percent of the radiocesium level set by the U.S. Food and Drug Administration for concern and intervention.

The researchers tested samples of the albacore from their loins, carcass and guts and found varying levels – all barely detectable. The findings are still important, however, since this is one of the first studies to look at different parts of the fish.

“The loins, or muscle, is what people eat and the bioaccumulation was about the same there as in the carcass,” said Jason Phillips, a research associate in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study.

The researchers next began looking at the radionuclide levels in different aged fish and found they were somewhat higher in 4-year-old albacore than in the younger fish. This suggests that the 3-year-old albacore may have only made one trans-Pacific migration, whereas the 4-year-old fish may have migrated through the Fukushima plume twice.

The majority of the 3-year-old fish had no traces of Fukushima at all.

Although it is possible that additional exposures to the plume could further increase radiation levels in the albacore, it would still be at a low level, the researchers pointed out. Additionally, as albacore mature at around age 5, they stop migrating long distances and move south to subtropical waters in the Central and West Pacific – and do not return to the West Coast of the United States.

“The presence of these radioactive isotopes is actually helping us in an odd way – giving us information that will allow us to estimate how albacore tuna migrate between our West Coast and Japan,” Neville said.

Little is known about the migration patterns of young albacore before they enter the U.S. fishery at about three years of age, Phillips said.

“That’s kind of surprising, considering what a valuable food source they are,” Phillips said. “Fukushima provides the only known source for a specific isotope that shows up in the albacore, so it gives us an unexpected fingerprint that allows us to learn more about the migration.”

Other authors were Richard Brodeur of NOAA’s Northwest Fisheries Science Center, and Kathryn Higley, of the OSU Department of Nuclear Engineering and Radiation Health Physics. The study was supported by Oregon State University and the National Oceanic and Atmospheric Administration, with continued support from Oregon Sea Grant.

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Delvan Neville,541-602-8005, dnevill@gmail.com; Jason Phillips, 541-231-5021, ajasonphillips@gmail.com

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Scientists successfully use krypton to accurately date ancient Antarctic ice

CORVALLIS, Ore. – A team of scientists has successfully identified the age of 120,000-year-old Antarctic ice using radiometric krypton dating – a new technique that may allow them to locate and date ice that is more than a million years old.

The ability to discover ancient ice is critical, the researchers say, because it will allow them to reconstruct the climate much farther back into Earth’s history and potentially understand the mechanisms that have triggered the planet to shift into and out of ice ages.

Results of the discovery are being published this week in the Proceedings of the National Academy of Sciences. The work was funded by the National Science Foundation and the U.S. Department of Energy.

“The oldest ice found in drilled cores is around 800,000 years old and with this new technique we think we can look in other regions and successfully date polar ice back as far as 1.5 million years,” said Christo Buizert, a postdoctoral researcher at Oregon State University and lead author on the PNAS article. “That is very exciting because a lot of interesting things happened with the Earth’s climate prior to 800,000 years ago that we currently cannot study in the ice core record.”

Krypton dating is much like the more-heralded carbon-14 dating technique that measures the decay of a radioactive isotope – which has constant and well-known decay rates – and compares it to a stable isotope. Unlike carbon-14, however, krypton is a noble gas that does not interact chemically and is much more stable with a half-life of around 230,000 years. Carbon dating doesn’t work well on ice because carbon-14 is produced in the ice itself by cosmic rays and only goes back some 50,000 years.

Krypton is produced by cosmic rays bombarding the Earth and then stored in air bubbles trapped within Antarctic ice. It has a radioactive isotope (krypton-81) that decays very slowly, and a stable isotope (krypton-83) that does not decay. Comparing the proportion of stable-to-radioactive isotopes provides the age of the ice.

Though scientists have been interested in radiokrypton dating for more than four decades, krypton-81 atoms are so limited and difficult to count that it wasn’t until a 2011 breakthrough in detector technology that krypton-81 dating became feasible for this kind of research. The new atom counter, named Atom Trap Trace Analysis, or ATTA, was developed by a team of nuclear physicists led by Zheng-Tian Lu at Argonne National Laboratory near Chicago.

In their experiment at Taylor Glacier in Antarctica, the researchers put several 300-kilogram (about 660 pounds) chunks of ice into a container and melted it to release the air from the bubbles, which was then stored in flasks. The krypton was isolated from the air at the University of Bern, Switzerland, and sent to Argonne for krypton-81 counting.

“The atom trap is so sensitive that it can capture and count individual atoms,” said Buizert, who is in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “The only problem is that there isn’t a lot of krypton in the air, and thus there isn’t much in the ice, either. That’s why we need such large samples to melt down.”

The group at Argonne is continually improving the ATTA detector, researchers there say, and they aim to perform analysis on an ice sample as small as 20 kilograms in the near future.

The researchers determined from the isotope ratio that the Taylor Glacier samples were 120,000 years old, and validated the estimate by comparing the results to well-dated ice core measurements of atmospheric methane and oxygen from that same period.

Now the challenge is to locate some of the oldest ice in Antarctica, which may not be as easy as it sounds.

“Most people assume that it’s a question of just drilling deeper for ice cores, but it’s not that simple,” said Edward Brook, an Oregon State University geologist and co-author on the study. “Very old ice probably exists in small isolated patches at the base of the ice sheet that have not yet been identified, but in many places it has probably melted and flowed out into the ocean.”

There also are special regions where old ice is exposed at the edges of an ice field, Brook pointed out.

“The international scientific community is really interested in exploring for old ice in both types of places and this new dating will really help,” Brook said. “There are places where meteorites originating from Mars have been pushed out by glaciers and collect at the margins. Some have been on Earth for a million years or more, so the ice in these spots may be that old as well.”

Buizert said reconstructing the Earth’s climate back to 1.5 million years is important because a shift in the frequency of ice ages took place in what is known as the Middle Pleistocene transition. The Earth is thought to have shifted in and out of ice ages every 100,000 years or so during the past 800,000 years, but there is evidence that such a shift took place every 40,000 years prior to that time.

“Why was there a transition from a 40,000-year cycle to a 100,000-year cycle?” Buizert said. “Some people believe a change in the level of atmospheric carbon dioxide may have played a role. That is one reason we are so anxious to find ice that will take us back further in time so we can further extend data on past carbon dioxide levels and test this hypothesis.”

In addition to Buizert and Brook, the research team included Daniel Baggenstos and Jeffrey Severinghaus of the Scripps Institution of Oceanography; Zheng-Tian Lu, Wei Jiang and Peter Müller, Argonne National Laboratory; Roland Purtschert, University of Bern; Vasilii Petrenko, University of Rochester; Tanner Kuhl, University of Wisconsin; James Lee, Oregon State University.

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Christo Buizert, 541-737-1209; buizertc@science.oregonstate.edu; Ed Brook, 541-737-8197, brooke@geo.oregonstate.edu

Volcanoes, including Mt. Hood, can go from dormant to active quickly

CORVALLIS, Ore. – A new study suggests that the magma sitting 4-5 kilometers beneath the surface of Oregon’s Mount Hood has been stored in near-solid conditions for thousands of years, but that the time it takes to liquefy and potentially erupt is surprisingly short – perhaps as little as a couple of months.

The key, scientists say, is to elevate the temperature of the rock to more than 750 degrees Celsius, which can happen when hot magma from deep within the Earth’s crust rises to the surface. It is the mixing of the two types of magma that triggered Mount Hood’s last two eruptions – about 220 and 1,500 years ago, said Adam Kent, an Oregon State University geologist and co-author of the study.

Results of the research, which was funded by the National Science Foundation, were published this week in the journal Nature.

“If the temperature of the rock is too cold, the magma is like peanut butter in a refrigerator,” Kent said. “It just isn’t very mobile. For Mount Hood, the threshold seems to be about 750 degrees (C) – if it warms up just 50 to 75 degrees above that, it greatly decreases the viscosity of the magma and makes it easier to mobilize.”

Thus the scientists are interested in the temperature at which magma resides in the crust, they say, since it is likely to have important influence over the timing and types of eruptions that could occur. The hotter magma from down deep warms the cooler magma stored at 4-5 kilometers, making it possible for both magmas to mix and to be transported to the surface to eventually produce an eruption.

The good news, Kent said, is that Mount Hood’s eruptions are not particularly violent. Instead of exploding, the magma tends to ooze out the top of the peak. A previous study by Kent and OSU postdoctoral researcher Alison Koleszar found that the mixing of the two magma sources – which have different compositions – is both a trigger to an eruption and a constraining factor on how violent it can be.

“What happens when they mix is what happens when you squeeze a tube of toothpaste in the middle,” said Kent, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “A big glob kind of plops out the top, but in the case of Mount Hood – it doesn’t blow the mountain to pieces.”

The collaborative study between Oregon State and the University of California, Davis is important because little was known about the physical conditions of magma storage and what it takes to mobilize the magma. Kent and UC-Davis colleague Kari Cooper, also a co-author on the Nature article, set out to find if they could determine how long Mount Hood’s magma chamber has been there, and in what condition.

When Mount Hood’s magma first rose up through the crust into its present-day chamber, it cooled and formed crystals. The researchers were able to document the age of the crystals by the rate of decay of naturally occurring radioactive elements. However, the growth of the crystals is also dictated by temperature – if the rock is too cold, they don’t grow as fast.

Thus the combination of the crystals’ age and apparent growth rate provides a geologic fingerprint for determining the approximate threshold for making the near-solid rock viscous enough to cause an eruption. The diffusion rate of the element strontium, which is also sensitive to temperature, helped validate the findings.

“What we found was that the magma has been stored beneath Mount Hood for at least 20,000 years – and probably more like 100,000 years,” Kent said. “And during the time it’s been there, it’s been in cold storage – like the peanut butter in the fridge – a minimum of 88 percent of the time, and likely more than 99 percent of the time.”

In other words – even though hot magma from below can quickly mobilize the magma chamber at 4-5 kilometers below the surface, most of the time magma is held under conditions that make it difficult for it to erupt.

“What is encouraging from another standpoint is that modern technology should be able to detect when magma is beginning to liquefy, or mobilize,” Kent said, “and that may give us warning of a potential eruption. Monitoring gases, utilizing seismic waves and studying ground deformation through GPS are a few of the techniques that could tell us that things are warming.”

The researchers hope to apply these techniques to other, larger volcanoes to see if they can determine their potential for shifting from cold storage to potential eruption, a development that might bring scientists a step closer to being able to forecast volcanic activity.

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Adam Kent, 541-737-1205

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2013 Weather Roundup: Wettest September doesn’t offset dry year

CORVALLIS, Ore. – The weather couldn’t seem to make up its mind what it had in store for Oregon in 2013. The state saw drought and the wettest September on record, as well as withering heat and sub-zero temperatures in the Willamette Valley.

An early December storm dropped several inches of snow on Corvallis, yet snowpack levels in the nearby Cascades are well below normal.

The United States drought monitor listed 100 percent of the state as at least abnormally dry in 2013, according to Kathie Dello, deputy director of the Oregon Climate Service at Oregon State University.

“All of Oregon is listed as dry, but southern Oregon has been historically dry in 2013,” said Dello, “and Medford and the southern coast have a chance to have their driest year on record.” As of mid-December, the Medford Airport had received just 8.97 inches of precipitation; the record dry year was set 1959 with 10.42 inches. The North Bend Airport was nearly five inches short of its driest year on record.

Despite abnormally dry conditions throughout Oregon for most of the year, it was soggy September. The month began with an enormous thunder and lightning storm that covered much of the state, triggering hundreds of fires and contributing to what Dello called a “bad wildfire year in Oregon.” The storm also dumped nearly three inches of rain on the southern Willamette Valley.

Near the end of the month, the remnants of a typhoon named Pabuk swept into the state and hammered western Oregon. Some precipitation monitors near Coos Bay recorded as much as 5.77 inches of rain on Sept. 29.

“Unfortunately, the September precipitation was not enough to offset dry conditions the rest of the year,” Dello said. “When it’s dry, that’s not how you want to receive you rainfall – in two major events. Rivers get only temporary relief and the torrential downpours can cause damage to agricultural crops.

“It’s better to have smaller, sustained rainfall events than a couple of major outbursts,” she added.

Oregon experienced a comparatively warm summer with more days than usual when temperatures exceeded 90 degrees, including the end of June and in September between the two rain events. On the other end of the spectrum, temperatures in early December plummeted to near-record lows as an Arctic front moved in.

Eugene, for example, recorded its second coldest day on record when the mercury hit minus-10 degrees on Dec. 8. Interestingly, it was not the coldest Dec. 8 on record as the all-time record low for Eugene of minus-12 degrees also occurred on Dec. 8 in 1972.

The December Arctic front hit the Corvallis area the hardest, though the weather station north of town at Hyslop Farm officially recorded just 4.5 inches of snow. Much of the area received 9-10 inches of powdery snow, forcing weeklong shutdowns of many schools and activities.

Dello said the lack of official weather recording stations in Oregon is one reason volunteers are needed for a statewide network that uses Oregon citizens to collect local data on rain, snow and even hail. The program is part of the national Community Collaborative Rain, Hail & Snow Network, or CoCoRaHS.

The Oregon Climate Service, which is part of OSU’s College of Earth, Ocean, and Atmospheric Sciences, coordinates the Oregon network. Persons interested in volunteering should go to the CoCoRaHS website at http://www.cocorahs.org/ to sign up.

“Data collected by volunteers throughout the state help provide us with much more accurate data, which leads to better precipitation maps and over the long haul, more accurate forecasting,” Dello said.

Among other highlights of Oregon’s 2013 weather year:

  • As of mid-December, the Eugene Airport had recorded 21.04 inches of precipitation; the record low was set in 1944 with 23.26 inches. Records there date back to 1911.
  • The Salem Airport had logged 23.41 inches through mid-December. The driest on record, dating back to 1940, is 23.77 inches.
  • The North Bend Airport is well ahead of the record dry year, set in 1976 with 33.52 inches. Through mid-December, the station had only recorded 28.67 inches. Records date to 1928.

Dello frequently provides weather facts and historical data via Twitter at: www.twitter.com/orclimatesvc.

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Weatherford Hall in the snow

Coastal survey: Oregon beaches see more short-term erosion

CORVALLIS, Ore. – A new assessment of shoreline change along the Pacific Northwest coast from the late 1800s to present found that while the majority of beaches are stable or slightly accreting (adding sand), many Oregon beaches have experienced an increase in erosion hazards in recent decades.

Since the 1960s, 13 of the 17 beach “littoral cells” – stretches of beach between rocky headlands and major inlets – in Oregon have shifted, either from a pattern of accretion to one of erosion, or to an increased amount of erosion, or they have built up less than in the past. Some of the hardest hit areas along the coast include the Neskowin littoral cell between Cascade Head and Pacific City, and the Beverly Beach littoral cell between Yaquina Head and Otter Rock, where shoreline change rates have averaged more than one meter of erosion a year since the 1960s.

The assessment is part of a series led by the U.S. Geological Survey to study shoreline change in the nation’s coastal regions to more comprehensively monitor coastal erosion and land loss.

Peter Ruggiero, an Oregon State University coastal hazards specialist and lead author on the report, said the findings provide baseline data to analyze future impacts of climate change, sea level rise and storms on the Northwest’s shorelines, he added.

“In a general sense, Oregon has faced much more erosion in the short term than has southwest Washington, which has seen more accretion as a result of sediments from the Columbia River and jetties at the mouth of the Columbia and at Gray’s Harbor,” said Ruggiero, an associate professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

“The Columbia has less of an influence on Oregon, and many of the state’s beaches have a relatively limited sediment supply,” Ruggiero added. “The buildup and loss of sand on our beaches is a natural process, but one that can be heavily influenced by human behavior and changes in climate.”

On a short-term basis, the study found that on average Northwest shorelines are “progradational” or growing at a rate of 0.9 meters a year. However, about 44 percent of the more than 9,000 transects the researchers studied were eroding.

Rob Thieler, a USGS scientist and leader of the agency’s coastal assessment effort, said these findings illustrate the variability of the Northwest shoreline and the factors that shape it.

“These new results help place coastal erosion in the Northwest into a local as well as national context that helps us understand how different coastlines function and which are the most vulnerable,” he said.

The lack of new sand has become a recent pattern among many beaches in Oregon, especially south of Tillamook Head because rivers are not delivering significant amounts of sand – and many estuaries trap the sediment before it reaches the ocean.

The Tillamook County area of Oregon is identified as one of the worst areas for erosion. The risk of land loss is significant from higher waves and rising sea levels, Ruggiero noted. Farther south, the impacts from these phenomena are partially countered by plate tectonics, he said.

“Over the long term, much of the shoreline is lifting because of plate tectonics,” said Ruggiero. “Along Oregon’s central coast, the uplift is only about a millimeter a year, while sea level rise has been about 2-3 mm per year. South of Coos Bay, however, the land is rising faster than the sea level is rising.”

Jonathan Allan, a researcher with the Oregon Department of Geology and Mineral Industries and a co-author on the report, said the Northwest coast has some “hot spots” where erosion has been significant and bluffs have failed, threatening houses.

“The beaches at Gleneden Beach and Neskowin, for example, contain coarse sand, which contrasts with the finer-grained beaches along much of the Oregon coast,” Allan said. “These beaches tend to be steeper and reflective of breaking wave energy, which makes them more dynamic. When coupled with the development of rip current embayments, it often results in hotspot erosion, which leads to the development of hazards when homes are placed too close to the beach.

“The issue is further complicated because at Neskowin, they have lost very large volumes of sand over the past 15 years, bringing the hazard even closer to the homes,” he added.

Ruggiero has been working with Tillamook County leaders and the Neskowin Coastal Hazards Committee on a response plan to erosion and climate change impacts. He and his colleagues are working to create new models predicting local impacts of sea level rise, and also incorporating socio-economic variables.

“It is important to look not only at the physical processes of sea level rise and inundation,” Ruggiero said, “but also to realistically look at the human dimension, including the cost of adaptation. Tillamook County has been actively addressing these issues.”

The USGS assessment focused on open-ocean sandy shores and did not look at Washington beaches along stretches of the Olympic Peninsula, Puget Sound or in Hood Canal because little data are available in those regions. But Ruggiero noted that many of the beaches in central and southern Washington were stable or adding sand, instead of eroding.

The study, “National Assessment of Shoreline Change: Historical Shoreline Change Along the Pacific Northwest Coast,” is available online at: http://pubs.usgs.gov/of/2012/1007/. Authors include Peter Ruggiero, OSU; Meredith G. Kratzmann, Emily A. Himmelstoss, and David Reid, USGS; Jonathan Allan, DOGAMI; and George Kaminsky, Washington Department of Ecology.

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Peter Ruggiero, 541-737-1239 (cell phone: 415-722-6722); ruggierp@science.oregonstate.edu

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Sea Clff Erosion
Sea cliff erosion near

Gleneden Beach, Ore.

 

 

Oregon littoral cells

Scientists calculate friction of Japan’s 9.0 earthquake in 2011

CORVALLIS, Ore. – An international team of scientists that installed a borehole temperature observatory following the 2011 Tohoku-Oki earthquake in Japan has been able to measure the “frictional heat” generated during the rupture of the fault – an amount the researchers say was smaller than expected, which means the fault is more slippery than previously thought.

It is the first time scientists have been able to use precise temperature measurements to calculate the friction dynamics of fault slip.

Results of the study are being published this week in the journal Science.

“This gives us some unprecedented insights into how earthquakes actually work,” said Robert Harris, a geophysicist at Oregon State University and co-author on the Science article. “No one really knows how much frictional resistance there is to slip and for the first time, this gives us some idea.

“The project itself was an engineering feat and an amazing one at that,” added Harris, who is a professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State. “To reach the fault, the team had to drill through 800 meters of the seafloor – at a depth of nearly 7,000 meters below the ocean’s surface. It pushed the limits of that technology as far as they can go.”

The study was funded by the Japan Agency for Marine-Earth Science and Technology, the Integrated Ocean Drilling Program, the National Science Foundation, and the Gordon and Betty Moore Foundation.

Sixteen months after the magnitude 9.0 Tohoku-Oki earthquake, the scientists installed the borehole observatory in a section of the fault where the slippage between one section of rock and the adjacent one was a staggering 50 meters. It was that huge slip in the fault that triggered the tsunami that killed thousands of people and devastated the northern coast of Japan.

After nine months of operation, the research team successfully retrieved 55 precise temperature-sensing data loggers that extended below the seafloor through the fault zone – the deepest of which was about 820 meters below the seafloor.

Evaluation of the data showed an anomaly of 0.31 degrees (Celsius) with surrounding temperatures at the boundary of the plate’s fault. When tectonic plates rub against each other, the frictional resistance to slip creates heat. By measuring changes to the background temperature field, they can calculate how much heat, or energy, was generated at the time of the earthquake.

“This is data that we’ve never had before,” Harris said. “It will be helpful in understanding the dynamics of earthquakes in the future.”

The scientists say this 0.31 temperature anomaly corresponds to 27 million joules, or 27 megajoules, per square meter of dissipated energy during the earthquake. A joule is the amount of energy required to produce one watt of power for one second. The “friction coefficient,” or the resistance to relative motion between the blocks, was surprisingly small at 0.08, the scientists point out.

“One way to look at the friction of these big blocks is to compare them to cross-country skis on snow,” Harris said. “At rest, the skis stick to the snow and it takes a certain amount of force to make them slide. Once you do, the ski’s movement generates heat and it takes much less force to continue the movement.

“The same thing happens with an earthquake,” he added. “This is the first time we’ve been able to calculate how much frictional resistance to slip there is. This has never been done before in nature – just in the laboratory.”

Harris said the scientists hope to repeat the experiment with other earthquakes, although the logistics of such a study are daunting – requiring a large earthquake with lots of slip, the ability to quickly drill a deep borehole and then monitoring the thermal signal. Similar experiments with other earthquakes will allow the scientists to better understand the hazards associated with large earthquakes.

“This was a major accomplishment,” he added, “but there is still a lot we don’t yet know.”

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 Rob Harris, 541-737-4370; rharris@coas.oregonstate.edu