OREGON STATE UNIVERSITY

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New assessment identifies global hotspots for water conflict

CORVALLIS, Ore. – More than 1,400 new dams or water diversion projects are planned or already under construction and many of them are on rivers flowing through multiple nations, fueling the potential for increased water conflict between some countries.

A new analysis commissioned by the United Nations uses a comprehensive combination of social, economic, political and environmental factors to identify areas around the world most at-risk for “hydro-political” strife. This river basins study was part of the U.N.’s Transboundary Waters Assessment Program.

Researchers from the United States, Spain and Chile took part in the analysis, which has been recommended by the U.N. Economic Commission for Europe as an indicator for the U.N.’s sustainable development goals for water cooperation.

Results of the study have just been published in the journal Global Environment Change. 

The analysis suggests that risks for conflict are projected to increase over the next 15 to 30 years in four hotspot regions – the Middle East, central Asia, the Ganges-Brahmaputra-Meghna basin, and the Orange and Limpopo basins in southern Africa.

Additionally, the Nile River in Africa, much of southern Asia, the Balkans in southeastern Europe, and upper South America are all areas where new dams are under construction and neighboring countries face increasing water demand, may lack workable treaties, or worse, haven’t even discussed the issue.

“If two countries have agreed on water flow and distribution when there’s a dam upstream, there usually is no conflict,” said Eric Sproles, an Oregon State University hydrologist and a co-author on the study. “Such is the case with the Columbia River basin between the United States and Canada, whose treaty is recognized as one of the most resilient and advanced agreements in the world. 

“Unfortunately, that isn’t the case with many other river systems, where a variety of factors come into play, including strong nationalism, political contentiousness, and drought or shifting climate conditions.”

The conflict over water isn’t restricted to human consumption, the researchers say. There is a global threat to biodiversity in many of the world’s river systems, and the risk of species extinction is moderate to very high in 70 percent of the area of transboundary river basins.

Asia has the highest number of dams proposed or under construction on transboundary basins of any continent with 807, followed by South America, 354; Europe, 148; Africa, 99; and North America, 8. But Africa has a higher level of hydro-political tension, the researchers say, with more exacerbating factors.

The Nile River, for example, is one of the more contentious areas of the globe. Ethiopia is constructing several dams on tributaries of the Nile in its uplands, which will divert water from countries downstream, including Egypt. Contributing to the tension is drought and a growing population more dependent on a water source that may be diminishing.

“When you look at a region, the first thing you try to identify is whether there is a treaty and, if so, is it one that works for all parties and is flexible enough to withstand change,” Sproles said. “It’s easy to plan for water if it is the same every year – sometimes even when it’s low. When conditions vary – and drought is a key factor – the tension tends to increase and conflict is more likely to occur.”

In addition to environmental variability and lack of treaties, other factors leading to conflict include political and economic instability, and armed conflict, the analysis shows.

Sproles said one reason the Columbia River Basin treaty between the U.S. and Canada has worked well is the relative stability of the water supply. In contrast, climate models suggest that the Orinoco River Basin in northern Brazil and the Amazon Basin in upper South America may face drier conditions, which could lead to more strife.

Sproles is a courtesy faculty member in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences, where he received his doctorate.

More information on the United Nations Transboundary Waters Assessment Program is available at: http://www.geftwap.org/.

A shorter version of the paper was published July 13 on the Sustainable Security website.

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OSU inks largest research grant in its history to begin ship construction

CORVALLIS, Ore. – Oregon State University has just received a grant of $121.88 million from the National Science Foundation to spearhead the construction of a new class of research vessels for the United States Academic Research Fleet. It is the largest grant in the university’s history.

This grant will fund the construction of the first of three planned vessels approved by Congress for research in coastal regions of the continental United States and Alaska. When funding for the next two vessels is authorized, the total grant to OSU could increase to as much as $365 million. The first vessel is slated to be operated by OSU for research missions focusing on the U.S. West Coast. The NSF will begin the competitive selection of operating institutions for the second and third vessels later this year – likely to universities or consortia for operations on the U.S. East Coast and the Gulf of Mexico.

“Oregon State University is extremely proud to lead this effort to create the next generation of regional ocean-going research vessels funded by NSF,” said OSU President Edward J. Ray. “Our exceptional marine science programs are uniquely positioned to advance knowledge of the oceans and to seek solutions to the threats facing healthy coastal communities – and more broadly, global ecological well-being – through their teaching and research.”

OSU was selected by the National Science Foundation in 2013 to lead the initial design phase for the new vessels, and to develop and execute a competitive selection for a shipyard in the United States to do the construction. Gulf Island Shipyards, LLC, in Louisiana was chosen and will conduct the detailed design verification over the next year. Officials hope to have a keel-laying ceremony for the first vessel in the spring of 2018, with the ship delivered to OSU for a year of extensive testing in 2020.

This new class of modern well-equipped ships is essential to support research encompassing marine physical, chemical, biological and geologic processes in coastal waters, said Roberta Marinelli, dean of Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

“Rising sea levels, ocean acidification, low-oxygen waters or ‘hypoxia,’ declining fisheries, offshore energy, and the threat of catastrophic tsunamis are issues not only in the Pacific Northwest but around the world,” Marinelli said. “These new vessels will provide valuable scientific capacity for better understanding our changing oceans.”

The ships will be equipped to conduct detailed seafloor mapping, to reveal geologic structures important to understanding processes such as subduction zone earthquakes that may trigger tsunamis. The Pacific Northwest is considered a high-risk region because of the Cascadia Subduction Zone, which has produced about two dozen major earthquakes of magnitude 8.0 or greater over the past 10,000 years.

The new ships will also be equipped with advanced sensors that will be used to detect and characterize harmful algal blooms, changing ocean chemistry, and the interactions between the sea and atmosphere. The emerging fields of wave, tidal and wind energy will benefit from ship observations. Oregon State is the site of the Northwest National Marine Renewable Energy Center, which in December was awarded a grant of up to $35 million from the U.S. Department of Energy to create the world’s premier wave energy test facility in Newport.

Some characteristics of the new regional class research vessels (RCRVs), which were designed by The Glosten Associates, a naval architecture firm based in Seattle:

  • 193 feet long with a 41-foot beam;
  • Range of approximately 7,000 nautical miles;
  • Cruising speed is 11.5 knots with a maximum speed of 13 knots;
  • 16 berths for scientists and 13 for crew members;
  • Ability to stay out at sea for at least 21 days before returning to port;
  • High bandwidth satellite communications for streaming data and video to shore;

“This class of ships will enable researchers to work much more safely and efficiently at sea because of better handling and stability, more capacity for instrumentation and less noise,” said Clare Reimers, a professor in the College of Earth, Ocean, and Atmospheric Sciences and project co-leader. “The design also has numerous ‘green’ features, including an optimized hull form, waste heat recovery, LED lighting, and variable speed power generation.”

Oregon State is expected to begin operating the first of the new ships in the fall of 2021, after a year of testing and then official Academic-Fleet designation by the University-National Oceanographic Laboratory System (UNOLS), according to Demian Bailey, also a project co-leader for OSU.

“There will be a full year of testing because there are many interconnected systems to try out,” Bailey said. “Any new ship needs to have shakedown cruises, but we’ll have to test all of the scientific instrumentation as well, from the acoustic multibeam seafloor mapping system to its seawater and meteorological data collection, processing and transfer capabilities.

“These ships will be very forward-looking and are expected to support science operations for 40 years or longer. They will be the most advanced ships of their kind in the country.”

OSU previously operated the 184-foot R/V Wecoma from 1975 until 2012, when it was retired. The university then assumed operations of Wecoma’s sister ship, R/V Oceanus, from Woods Hole Oceanographic Institution; that ship will be retired when the new ship is ready.

The tentative timetable for the new ships:

  • Ship No. 1 keel laying – spring 2018;
  • Ship No. 1 transition to OSU for a year of testing – fall 2020;
  • Ship No. 1 should be fully tested, have UNOLS designation and be fully operational by fall 2021;
  • Ship No. 2 – Keel laying in winter of 2018, delivery in spring 2021, and UNOLS designation in late spring 2022;
  • Ship No. 3 – Keel laying in fall 2020, delivery in spring 2022, and UNOLS designation in spring 2023.

More information on the ships and the project is available at: http://ceoas.oregonstate.edu/ships/rcrv/.

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Regional class research vessel

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Study finds Earth’s magnetic field ‘simpler than we thought’

CORVALLIS, Ore. – Scientists have identified patterns in the Earth’s magnetic field that evolve on the order of 1,000 years, providing new insight into how the field works and adding a measure of predictability to changes in the field not previously known.

The discovery also will allow researchers to study the planet’s past with finer resolution by using this geomagnetic “fingerprint” to compare sediment cores taken from the Atlantic and Pacific oceans.

Results of the research, which was supported by the National Science Foundation, were recently published in Earth and Planetary Science Letters.

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say. The field also aids in human navigation and animal migrations in ways scientists are only beginning to understand. Centuries of human observation, as well as the geologic record, show our field changes dramatically in its strength and structure over time.

Yet in spite of its importance, many questions remain unanswered about why and how these changes occur. The simplest form of magnetic field comes from a dipole: a pair of equally and oppositely charged poles, like a bar magnet.

“We’ve known for some time that the Earth is not a perfect dipole, and we can see these imperfections in the historical record,” said Maureen “Mo” Walczak, a post-doctoral researcher at Oregon State University and lead author on the study. “We are finding that non-dipolar structures are not evanescent, unpredictable things. They are very long-lived, recurring over 10,000 years – persistent in their location throughout the Holocene.

“This is something of a Holy Grail discovery,” she added, “though it is not perfect. It is an important first step in better understanding the magnetic field, and synchronizing sediment core data at a finer scale.”

Some 800,000 years ago, a magnetic compass’ needle would have pointed south because the Earth’s magnetic field was reversed. These reversals typically happen every several hundred thousand years.

While scientists are well aware of the pattern of reversals in the Earth’s magnetic field, a secondary pattern of geomagnetic “wobble” within periods of stable polarity, known as paleomagnetic secular variation, or PSV, may be a key to understanding why some geomagnetic changes occur. 

The Earth’s magnetic field does not align perfectly with the axis of rotation, which is why “true north” differs from “magnetic north,” the researchers say. In the Northern Hemisphere this disparity in the modern field is apparently driven by regions of high geomagnetic intensity that are centered beneath North America and Asia.

“What we have not known is whether this snapshot has any longer-term meaning – and what we have found out is that it does,” said Joseph Stoner, an Oregon State University paleomagnetic specialist and co-author on the study. 

When the magnetic field is stronger beneath North America, or in the “North American Mode,” it drives steep inclinations and high intensities in the North Pacific, and low intensities in Europe with westward declinations in the North Atlantic. This is more consistent with the historical record.

The alternate “European mode” is in some ways the opposite, with shallow inclination and low intensity in North Pacific, and eastward declinations in the North Atlantic and high intensities in Europe.

“As it turns out, the magnetic field is somewhat less complicated than we thought,” Stoner said. “It is a fairly simple oscillation that appears to result from geomagnetic intensity variations at just a few recurrent locations with large spatial impacts. We’re not yet sure what drives this variation, though it is likely a combination of factors including convection of the outer core that may be biased in configuration by the lowermost mantle.”

The researchers were able to identify the pattern by studying two high-resolution sediment cores from the Gulf of Alaska that allowed them to develop a 17,400-year reconstruction of the PSV in that region. They then compared those records with sediment cores from other sites in the Pacific Ocean to capture a magnetic fingerprint, which is based on the orientation of the magnetite in the sediment, which acts as a magnetic recorder of the past.

The common magnetic signal found in the cores now covers an area spanning from Alaska to Oregon, and over to Hawaii.

“Magnetic alignment of distant environmental reconstructions using reversals in the paleomagnetic record provides insights into the past on a scale of hundreds of thousands of years,” Walczak said. “Development of the coherent PSV stratigraphy will let us look at the record on a scale possibly as short as a few centuries, compare events between ocean basins, and really get down to the nitty-gritty of how climate anomalies are propagated around the planet on a scale relevant to human society.”

The magnetic field is generated within the Earth by a fluid outer core of iron, nickel and other metals that creates electric currents, which in turn produce magnetic fields. The magnetic field is strong enough to shield the Earth from solar winds and cosmic radiation. The fact that it changes is well known; the reasons why have remained a mystery.

Now this mystery may be a little closer to being solved.

Walczak and Stoner are in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. Other authors on the study are Alan Mix, also of OSU; John Jaeger, Gillian Rosen and James Channell of the University of Florida; David Heslop of Australian National University; and Chuang Xuan of the University of Southampton.

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Krill hotspot fuels incredible biodiversity in Antarctic region

CORVALLIS, Ore. – There are so many Antarctic krill in the Southern Ocean that the combined mass of these tiny aquatic organisms is more than that of the world’s 7.5 billion human inhabitants.

Scientists have long known about this important zooplankton species, but they haven’t been certain why particular regions or “hotspots” in the Southern Ocean are so productive. One such hotspot exists off Anvers Island – along the western Antarctic Peninsula – where high densities of Antarctic krill episodically concentrate near the shore close to a number of Adélie penguin breeding colonies. 

As it turns out, a perfect combination of tides and wind is responsible, according to scientists who just published a study on the krill in the journal Deep Sea Research. The research was funded by the National Science Foundation.

“This region off the western Antarctic Peninsula has been a known breeding area for Adélie penguins for thousands of years,” said Kim Bernard, a biological oceanographer at Oregon State University and lead author on the study. “We know it today as a krill hotspot and it probably has been for some time.

“But despite their abundance, there is growing concern about krill not only because of climate change, but because they are now being harvested for human food, nutritional supplements and aquaculture feed. Yet historically we’ve known little about what makes this particular area so productive for krill. So we set out to learn more about it.”

Bernard and a team of colleagues spent four consecutive summer seasons in the Antarctic mapping the patterns in distribution and biomass of Antarctic krill, also known as Euphausia superba. They also sought to identify the environmental conditions responsible for the hotspot. 

What they discovered is a near-perfect system in which krill aggregations situated over the Palm Deep Canyon – a region of nutrient-rich waters that produce a lot of food for the krill – are delivered close to shore by tidal currents and winds. When the winds are westerly and the tides are diurnal – one high tide and one low tide each day – the krill biomass close to shore is at its peak and krill aggregations are huge.

“It’s neat – we can predict exactly when humpback whales will be close to shore off Palmer Station just based on the tides,” Bernard said. “When there are diurnal tides, you’ll see krill from the surface to the ocean floor – they are everywhere. And when they are, the whales are there, too.

“This concentration and transport toward shore are particularly important for the penguins that breed there. The farther they have to go to forage, the less their chicks have to eat and chick weight is a huge factor in their survival. A difference of a few hundred grams in chick weight is the difference between life and death.”

When the tides shift to semi-diurnal – two high and two low tides daily – currents move the krill away from shore and their predators follow. Likewise, a shift to southerly winds keeps the krill farther from shore and more spread out.

Antarctic krill can live five to seven years, and grow to a length of a little more than two inches. They don’t reach sexual maturity for two years, and when they reproduce, they must release their eggs in water roughly 1,000 meters (or about 3,200 feet) deep. That’s because they need a certain period of time to develop as they drift to the ocean floor, and another period of time to go through different life stages as they re-ascend to the surface.

Studies have shown that sea ice may be critical to their survival, but scientists are not exactly sure why, Bernard said.

“We see very strong correlations between krill biomass and sea ice,” she noted. “When the sea ice is low, the krill populations crash the next summer. It could be a change in algae or other food for them, or it could be that sea ice provides shelter from predators, or affects the currents in some way. We just don’t yet know.

“It would be nice to find out, because sea ice abundance may vary greatly in the future.”

Bernard is on the faculty of OSU’s College of Earth, Ocean, and Atmospheric Sciences.

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Penguins rely on close-to-shore krill

Analyzing magma temperatures may help get closer to forecasting volcanic eruptions

CORVALLIS, Ore. – Although volcanic eruptions are often quite hazardous, scientists have been unable to pinpoint the processes leading up to major eruptions – and one important limitation has been a lack of knowledge about the temperature history of the magma.

A new study analyzed crystals of the mineral zircon – zirconium silicate – in magma from an eruption in the Taupo Volcanic Zone in New Zealand about 700 years ago to determine the magma’s history. The analysis shows the magma went through a comparatively “cool” period for thousands of years before heating up. Once magma temperatures reached 750 degrees Celsius, it was a short amount of time – decades or less – before an eruption occurred.

This pattern of long-term crystal storage in near-solid magma, punctuated by rapid heating, is applicable to many other volcanoes around the world, the researchers say, and may begin to help scientists recognize when a volcano is heading toward an eruptive phase.

Results of the research, which was supported by the National Science Foundation, are being reported this week in Science.

“Mobility in magma is a function of temperature and most of the time when it’s sitting there in the Earth’s crust under the volcano it’s cool,” said Adam Kent, an Oregon State University geologist and co-author on the study. “Of course, cool is a relative description since it’s still some 650 degrees (Celsius). I wouldn’t put my finger on it.

“But to erupt onto the Earth’s surface magma needs to heat up so it can be runny enough to be squeezed along cracks in the Earth and pushed up to the surface. At lower temperatures, the magma is too crystal-rich and viscous to move. It’s like trying to spread cold peanut butter onto a piece of bread. It takes higher temperatures to get things moving – and then our data show it’s only a period of years or decades before it erupts.”

Kent said the Taupo magma system has similarities to many volcanoes around the world, including the Cascade Range in the Pacific Northwest of the United States. A past study by Kent and his colleagues using a different approach found that Mount Hood in Oregon also spent most of its history in a cold, rigid state before moving rapidly into an eruptive phase.

This new study adds more certainty to the method and provides a new tool to apply this work to other volcanoes, the researchers say.

The key to honing in on these long-term geologic processes is understanding the volcanoes’ thermal or temperature history, according to the researchers. Past studies began making inroads into understanding the history of magma temperatures, but they relied on trying to reconcile data from a sample containing many thousands of individual crystals.

Using zircon crystals, which can be dated through analyzing the decay of uranium and thorium, adds more resolution, or precision, to the process. The crystals are like a “black box” flight recorder for studying volcanic eruptions, according to Kari Cooper of the University of California, Davis, corresponding author on the study.

“Instead of trying to piece together what happened from the wreckage,” Cooper said, “the crystals can tell us what was going on while they were below the surface, including the runup to an eruption.”

Zircon crystals occur in magma from many volcanoes and the new technique will have wide applications to volcanoes along the ring of fire – the belt of volcanoes that surround the Pacific Ocean – and elsewhere.

“It removes some uncertainty and gives us a great new tool to go back and look at other volcanoes,” Kent said.

The finding also suggests that if many volcanoes store their magma in this relatively cold state, recognizing volcanoes where warm and mobile magma is present may help researchers find volcanoes in the early throes of producing future eruptions. The technology to monitor volcanoes using seismic waves and other remote techniques is improving all the time, the researchers said.

The Science study was led by Allison Rubin and Cooper of the University of California at Davis. Other researchers included Christy Till and Maitrayee Bose of Arizona State University; Fidel Costa, Nanyang Technological University of Singapore; Darren Gravley and Jim Cole of the University of Canterbury in New Zealand; and Chad Deering, Michigan Technological University.

Kent is on the faculty of the College of Earth, Ocean, and Atmospheric Sciences at Oregon State.

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Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe

CORVALLIS, Ore. – Sediment that eroded from the Himalayas and Tibetan plateau over millions of years was transported thousands of kilometers by rivers and in the Indian Ocean – and became sufficiently thick over time to generate temperatures warm enough to strengthen the sediment and increase the severity of the catastrophic 2004 Sumatra earthquake.

The magnitude 9.2 earthquake on Dec. 26, 2004, generated a massive tsunami that devastated coastal regions of the Indian Ocean. The earthquake and tsunami together killed more than 250,000 people making it one of the deadliest natural disasters in history.

An international team of scientists that outlined the process of sediment warming says the same mechanism could be in place in the Cascadia Subduction Zone off the Pacific Northwest coast of North America, as well as off Iran, Pakistan and in the Caribbean.

Results of the research, which was conducted as part of the International Ocean Discovery Program, are being published this week in the journal Science.

“The 2004 Indian Ocean tsunami was triggered by an unusually strong earthquake with an extensive rupture area,” said expedition co-leader Lisa McNeill, an Oregon State University graduate now at the University of Southampton. “We wanted to find out what caused such a large earthquake and tsunami, and what it might mean for other regions with similar geological properties.”

The research team sampled for the first time sediment and rocks from the tectonic plate that feeds the Sumatra subduction zone. From the research vessel JOIDES Resolution, the team drilled down 1.5 kilometers below the seabed, measured different properties of the sediments, and ran simulations to calculate how the sediment and rock behaves as it piles up and travels eastward 250 kilometers toward the subduction zone.

“We discovered that in some areas where the sediments are especially thick, dehydration of the sediments occurred before they were subducted,” noted Marta Torres, an Oregon State University geochemist and co-author on the study. “Previous earthquake models assumed that dehydration occurred after the material was subducted, but we had suspected that it might be happening earlier in some margins.

“The earlier dehydration creates stronger, more rigid material prior to subduction, resulting in a very large fault area that is prone to rupture and can lead to a bigger and more dangerous earthquake.”

Torres explained that when the scientists examined the sediments, they found water between the sediment grains that was less salty than seawater only within a zone where the plate boundary fault develops, some 1.2 to 1.4 kilometers below the seafloor.

“This along with some other chemical changes are clear signals that it was an increase in temperature from the thick accumulation of sediment that was dehydrating the minerals,” Torres said.

Lead author Andre Hüpers of the University of Bremen in Germany said that the discovery will generate new interest in other subduction zone sites that also have thick, hot sediment and rock, especially those areas where the hazard potential is unknown.

The Cascadia Subduction Zone is one of the most widely studied sites in the world and experts say it may have experienced as many as two dozen major earthquakes over the past 10,000 years.

The sediment at the Cascadia deformation front is between 2.5 and 4.0 kilometers thick, which is somewhat less than the 4-5 kilometer thickness of the Sumatra region. However, because the subducting plate at Cascadia is younger when the plate arrives at the subduction zone, the estimated temperatures at the fault surface are about the same in both regions.

Torres is a professor in Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences.

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Marta Torres, 541-737-2902, mtorres@coas.oregonstate.edu

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Sediment cores

Sediment cores

New study documents aftermath of a supereruption, and expands size of Toba magma system

CORVALLIS, Ore. – The rare but spectacular eruptions of supervolcanoes can cause massive destruction and affect climate patterns on a global scale for decades – and a new study has found that these sites also may experience ongoing, albeit smaller eruptions for tens of thousands of years after.

In fact, Oregon State University researchers were able to link recent eruptions at Mt. Sinabung in northern Sumatra to the last eruption on Earth of a supervolcano 74,000 years ago at the Toba Caldera some 25 miles away.

The findings are being reported this week in the journal Nature Communications.

“The recovery from a supervolcanic eruption is a long process, as the volcano and the magmatic system try to re-establish equilibrium – like a body of water that has been disrupted by a rock being dropped into it,” said Adonara Mucek, an Oregon State doctoral candidate and lead author on the study.

“At Toba, it appears that the eruptions continued for at least 15,000 to 20,000 years after the supereruption and the structural adjustment continued at least until a few centuries ago – and probably is continuing today. It is the magmatic equivalent to aftershocks following an earthquake.”

This is the first time that scientists have been able to pinpoint what happens following the eruption of a supervolcano. To qualify as a supervolcano, the eruption must reach at least magnitude 8 on the Volcano Explosivity Index, which means the measured deposits for that eruption are greater than 1,000 cubic kilometers, or 240 cubic miles.

When Toba erupted, it emitted a volume of magma 28,000 times greater than that of the 1980 eruption of Mount St. Helens in Washington state. It was so massive, it is thought to have created a volcanic winter on Earth lasting years, and possibly triggering a bottleneck in human evolution.

Other well-known supervolcano sites include Yellowstone Park in the United States, Taupo Caldera in New Zealand, and Campi Flegrei in Italy.

“Supervolcanoes have lifetimes of millions of years during which there can be several supereruptions,” said Shanaka “Shan” de Silva, an Oregon State University volcanologist and co-author on the study. “Between those eruptions, they don’t die. Scientists have long suspected that eruptions continue after the initial eruption, but this is the first time we’ve been able to put accurate ages with those eruptions.”

Previous argon dating studies had provided rough ages of eruptions at Toba, but those eruption dates had too much range of error, the researchers say. In their study, the OSU researchers and their colleagues from Australia, Germany, the United States and Indonesia were able to decipher the most recent volcanic history of Toba by measuring the amount of helium remaining in zircon crystals in erupted pumice and lava.

The helium remaining in the crystals is a remnant of the decaying process of uranium, which has a well-understood radioactive decay path and half-life.

“Toba is at least 1.3 million years old, its supereruption took place about 74,000 years ago, and it had at least six definitive eruptions after that – and probably several more,” Mucek said. “The last eruption we have detected occurred about 56,000 years ago, but there are other eruptions that remain to be studied.”

The researchers also managed to estimate the history of structural adjustment at Toba using carbon-14 dating of lake sediment that has been uplifted up to 600 meters above the lake in which they formed. These data show that structural adjustment continued from at least 30,000 years ago until 2,000 years ago – and may be continuing today.

The study also found that the magma in Toba’s system has an identical chemical fingerprint and zircon crystallization history to Mt. Sinabung, which is currently erupting and is distinct from other volcanoes in Sumatra. This suggests that the Toba system may be larger and more widespread than previously thought, de Silva noted.

“Our data suggest that the recent and ongoing eruptions of Mt. Sinabung are part of the Toba system’s recovery process from the supereruption,” he said.

The discovery of the connection does not suggest that the Toba Caldera is in danger of erupting on a catastrophic scale any time soon, the researchers emphasized. “This is probably ‘business as usual’ for a recovering supervolcano,” de Silva said. It does emphasize the importance of having more sophisticated and frequent monitoring of the site to measure the uplift of the ground and image the magma system, the researchers note.

“The hazards from a supervolcano don’t stop after the initial eruption,” de Silva said. “They change to more local and regional hazards from eruptions, earthquakes, landslides and tsunamis that may continue regularly for several tens of thousands of years.

“Toba remains alive and active today.”

As large as the Toba eruption was, the reservoir of magma below the caldera is much, much greater, the researchers say. Studies at other calderas around Earth, such as Yellowstone, have estimated that there is between 10 and 50 times as much magma than is erupted during a supereruption.

Mucek and de Silva are affiliated with OSU’s College of Earth, Ocean, and Atmospheric Sciences. The study was supported by the National Science Foundation. A video of them explaining their research is available at: http://bit.ly/2raULAx

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Adonara “Ado” Mucek, 541-908-1437, muceka@geo.oregonstate.edu;

Shanaka “Shan” de Silva, 541-737-1212, desilvas@geo.oregonstate.edu;

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Southward view of the northern third of the Lake Toba depression produced by the supereruption 74,000 years ago.

“Narco-deforestation” study links loss of Central American tropical forests to cocaine

CORVALLIS, Ore. – Central American tropical forests are beginning to disappear at an alarming rate, threatening the livelihood of indigenous peoples there and endangering some of the most biologically diverse ecosystems in North America.

The culprit? Cocaine.

The problem is not the cultivation of the coca plant – which is processed into cocaine – that is causing this “narco-deforestation.” It results from people throughout the spectrum of the drug trade purchasing enormous amounts of land to launder their illegal profits, researchers say.

Results of the study, which was funded by the Open Society Foundations and supported by the National Socio-Environmental Synthesis Center, have just been published in the journal Environmental Research Letters.

“Starting in the early 2000s, the United States-led drug enforcement in the Caribbean and Mexico pushed drug traffickers into places that were harder to patrol, like the large, forested areas of central America,” said David Wrathall, an Oregon State University geographer and co-author on the study. “A flood of illegal drug money entered these places and these drug traffickers needed a way that they could spend it.

“It turns out that one of the best ways to launder illegal drug money is to fence off huge parcels of forest, cut down the trees, and build yourself a cattle ranch. It is a major, unrecognized driver of tropical deforestation in Central America.”

Using data from the Global Forest Change program estimating deforestation, the research team identified irregular or abnormal deforestation from 2001-2014 that did not fit previously identified spatial or temporal patterns caused by more typical forms of land settlement or frontier colonization. The team then estimated the degree to which narcotics trafficking contributes to forest loss, using a set of 15 metrics developed from the data to determine the rate, timing and extent of deforestation.

Strongly outlying or anomalous patches and deforestation rates were then compared to data from the Office of National Drug Control Policy – considered the best source for estimating cocaine flow through the Central American corridor, Wrathall pointed out.

“The comparisons helped confirm relationships between deforestation and activities including cattle ranching, illegal logging, and land speculation, which traffickers use to launder drug trafficking profits in remote forest areas of Central America,” Wrathall said.

They estimate that cocaine trafficking may account for up to 30 percent of the total forest loss in Honduras, Guatemala and Nicaragua over the past decade. A total of 30 to 60 percent of the forest losses occurred within nationally and internationally designated protected areas, threatening conservation efforts to maintain forest carbon sinks, ecological services, and rural and indigenous livelihoods.

“Imagine the cloud of carbon dioxide from all of that burning forest,” Wrathall said. “The most explosive change in land use happened in areas where land ownership isn’t clear – in forested, remote areas of Honduras, Guatemala and Nicaragua, where the question of who owns the land is murky.”

“In Panama, the financial system is built to launder cocaine money so they don’t need to cut down trees to build ranches for money laundering. In Honduras, land is the bank.”

Farming and cattle ranching aren’t the only money laundering methods threatening tropical forests, the researchers say. Mining, tourism ventures and industrial agriculture are other ways drug money is funneled into legitimate businesses.

Wrathall said the impact affects both people and ecosystems.

“The indigenous people who have lived sustainably in these environments are being displaced as the stewards of the land,” he said. “These are very important ecological areas with tremendous biodiversity that may be lost.”

The authors says the solutions include de-escalating and demilitarizing the war on drugs; strengthening the position of indigenous peoples and traditional forest communities to be stewards of the remaining forest lands; and developing regional awareness of the issue.

“We are cruising through the last of our wild spaces in Central America,” Wrathall said. “Obviously, ending the illegal drug trade would be the best solution, but that isn’t going to happen. In fact, when drug enforcement efforts are successful, they often push the activity into remote areas that haven’t had issues before, such as remote biodiversity hotspots.”

Wrathall is an assistant professor in Oregon State University’s College of Earth, Ocean, and Atmospheric Sciences. He specializes in the impact of climate change on the distribution of the human population and other factors that affect human migration.

“The surge of violence in Central America that has accompanied drug trafficking is recognized as a major driver of migration in the region.”

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David Wrathall, 541-737-8051, david.wrathall@coas.oregonstate.edu

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Central American forests are giving way to pasture land for cattle ranches.

New book: Rivers are like the stock market, with boom and bust cycles

CORVALLIS, Ore. – Rivers have long captured the imagination of poets, essayists and other writers, who have used them to tell iconic stories like “Huckleberry Finn,” “The Heart of Darkness,” and “Wind and the Willows.”

Oregon State University geophysicist and author Sean Fleming explores rivers from different angles – where they come from, why they may flood one year and dry up the next, and how almost every aspect of our lives revolves around water.

In his new book “Where the River Flows,” published by the Princeton University Press, Fleming explains that mathematics and physics give us a fresh way to look at rivers. Not to worry, though – it is a book aimed at the lay public and presented in a unique style. He asks questions such as “how do rivers remember?” and “how do clouds talk to fish?” as a way to introduce new topics.

“Ultimately, almost everything revolves around water, from the food we eat and the beer we drink, to hydroelectric power and recreation,” Fleming said. “Rivers are essential to civilization and even life itself, but people rarely delve into what makes them work. And in an interesting way, mathematical ideas underlie the science of rivers and underscore the importance of interconnectedness.”

Fleming uses debris flows as an example. This flood and landslide hybrid, which poses threats around the world, can be explained using a computer simulation called “cellular automata,” which originally was created to explore artificial life.

“It also reveals something about the origins of fractal patterns, which occur in everything from tree branches, to galaxies to the stock market,” Fleming said. “Recognizing that ideas from one field can be so powerful in another is important for pushing science forward.”

In his book, Fleming also points out some oddities about rivers across the world. For example, most rivers have seasonal “heart-beats,” he pointed out, with one peak per year – like the Columbia River’s springtime snowmelt freshet. Across the globe, however, Africa’s Congo River is so big and covers so much territory on either side of the equator that it has two peaks and two troughs because when it is summer in one part of the river it is winter in the other.

The Colorado River provides another oddity. In the upper Colorado, the water flow is impressive, attracting white water rafters for its massive rapids and thrills. But the river doesn’t even end up flowing into the Pacific Ocean any longer because of the demand of people living along its path. That is well-documented. The backdrop to the water usage, however, is not as widely known, Fleming noted.

“The allocations for water from the Colorado River were made in the early 1900s,” he said. “They were based on the observed weather and stream flow at the time, which were expected to remain roughly the same. But little did they know that it turned out to be one of the wettest periods in the basin’s history.

“So the allotments then – and today – were made on the assumption that the river’s flow would be much greater than it actually is.”

Fleming also explores issues of water security and the increasing demand worldwide for fresh water.

“That demand is expected to increase 55 percent by the year 2050, so we may be looking at increased opportunities for cooperation, but also conflict,” he said. “Some people have even predicted water wars. To better manage the resource, we need to make a quantum leap forward in understanding how rivers work and that means looking at them from all angles.”

“Where the River Flows: Scientific Reflections on Earth’s Waterways” is available through the Princeton University Press at: http://press.princeton.edu/titles/10978.html and at Amazon at: http://amzn.to/2r3eOR4

Fleming is a courtesy faculty member in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

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Sean Fleming, fleminse@oregonstate.edu

Magnesium within plankton provides tool for taking the temperatures of past oceans

CORVALLIS, Ore. – Scientists cannot travel into the past to take the Earth’s temperature so they use proxies to discern past climates, and one of the most common methods for obtaining such data is derived from the remains of tiny marine organisms called foraminifera found in oceanic sediment cores.

These “forams,” as they are called, are sand-grained-sized marine protists that make shells composed of calcite. When they grow, they incorporate magnesium from seawater into their shells. When ocean temperatures are warmer, forams incorporate more magnesium; less when the temperatures are cooler. As a result, scientists can tell from the amount of magnesium what the temperature of the seawater was thousands, even millions of years ago. These proxies are important tools for understanding past climate.

However, studies of live forams reveal that shell magnesium can vary, even when seawater temperature is constant. A new study published this week in the journal Nature Communications affirms that magnesium variability is linked to the day/night (light/dark) cycle in simple, single-celled forams and extends the findings to more complex multi-chambered foraminifera.

To understand how forams develop and what causes magnesium variability, the team of scientists from Oregon State, University of California, Davis, University of Washington and Pacific Northwest National Laboratory grew the multi-chambered species, Neogloboquadrina dutertrei, in a laboratory under highly controlled conditions. They used high-resolution imaging techniques to “map” the composition of these lab-grown specimens.

“We found that high-magnesium is precipitated at night, and low-magnesium is added to the shells during the day, similar to the growth patterns of the single-chambered species,” said Jennifer S. Fehrenbacher, an ocean biogeochemist and paleoceanographer at Oregon State University and lead author on the study. “This confirms that magnesium variability is driven by the same mechanism in two species with two different ecological niches. We can now say with some level of confidence that magnesium-banding is intrinsically linked to shell formation processes as opposed to other environmental factors.

“The variability in magnesium content of the shells doesn’t change the utility of forams as a proxy for temperature. Rather, our results give us new insights into how these organisms build their shells and lends confidence to their utility as tools for reconstructing temperatures.”

Other co-authors on this study are Ann Russell, Catherine Davis, and Howard Spero at the University of California, Davis; Alex Gagnon at the University of Washington, Zihua Zhu and John Cliff at the Pacific Northwest National Laboratory, and Pamela Martin.

The study was funded by the National Science Foundation and the Department of Energy. Fehrenbacher is an assistant professor in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

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 Jennifer Fehrenbacher, 541-737-6285, fehrenje@coas.oregonstate.edu

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N. dutertrei

N. dutertrei grown in a laboratory