OREGON STATE UNIVERSITY

marine science and the coast

Extreme Tides in November, December Provide Hazards – and a Challenge for Scientists

NEWPORT, Ore. – A series of extremely high tides, directly followed by strong “minus” tides, may provide more than a curiosity of nature along the Oregon coast this November and December.

The resulting tidal surge – especially if accompanied by a strong storm – can create danger for boaters and beachcombers – and threaten oceanfront homes with erosion and high water, according to ocean experts at Oregon State University.

And strong tide changes create an interesting dynamic at river bars – the creation of unpredictable, sharp-breaking waves that have claimed the lives of numerous boaters in Oregon.

“The Oregon coast is a dynamic place and when you get a combination of storms, extreme tides and high waves mixed in with a strong river current, it can get pretty wild,” said Tuba Ozkan-Haller, an assistant professor in OSU’s College of Oceanic and Atmospheric Sciences and an expert on nearshore and beach processes.

“The Columbia River is a great example of that,” she added. “There’s a reason why the mouth has been called the ‘graveyard of the Pacific Ocean.’ But it isn’t alone. In conditions like these, most of the bars and mouths of rivers in Oregon can be a hazardous place to be.”

Tidal measurements vary along the coast, but high tides reaching 10.0 feet at OSU’s Hatfield Marine Science Center in Newport are considered quite strong. On Friday, Nov. 23, the predicted high tide is 10.3 feet at 10:04 a.m.; and on Saturday (10:48 a.m.) and Sunday (11:33 a.m.), the high tides are projected to reach a lofty 10.6 feet.

Ocean water surging inland can carry high onto beaches, especially if the tidal impact is exacerbated by a strong storm, which increases the chances of coastal erosion. But it is the outgoing tide that concerns Ozkan-Haller, who has been studying the effects of where tidal currents meet ocean waves.

“When ocean waves come into shore, they eventually reach shallower water and shoal up,” she said. “They get shorter and steeper, and they can break offshore – typically off the mouths of bars. When the outgoing tide is strong, the impact on the waves can be quite significant. It can create a real problem for boats – not just recreational fishermen, but large, ocean-going cargo ships as well.”

And that is the challenge nature is throwing in November. Those huge 10.6-foot high tides are followed on Saturday and Sunday by -2.1 and -2.2 (minus) tides. That is nearly a 13-foot difference between high and low tides, Ozkan-Haller pointed out.

In her studies, Ozkan-Haller has found that even a modest 4-meter wave rolling toward the Oregon coast will grow to five meters as it begins to shoal. When it comes up against an average outgoing tide, it will grow to six meters. The stronger the tides, she says, the greater the impact on wave heights. Throw a storm, or high swells into the mix, and modest waves can become intimidating.

What the researchers haven’t yet discovered is how and when those tide-induced waves will break, she said.

“We’ve been working with bar pilots on the Columbia, who are desperate for some kind of predictive capability for waves breaking at the mouth of the river,” Ozkan-Haller said. “Bar pilots have to make a decision about leaving Portland 6-8 hours before reaching the bar and once they go, they’re committed. Many of the larger ships are too big to turn around, and there may not be enough room downriver to anchor safely.

“Making those decisions is an art based on experience and the observation of other pilots,” she added. “We’re trying to help add some research-based science to their extraordinary art.”

Scientists have capably demonstrated an ability to create models that predict when there will be whitecaps off the coast and when waves will break because of shallow water. However, preliminary attempts to predict when current-induced waves will break haven’t been successful and Ozkan-Haller and colleagues are seeking funding to initiate a project focusing on the Columbia River.

It’s a complicated world off the Oregon coast. And when surging high tides are followed by extreme minus tides, the turbulent nearshore processes become even more pronounced.

“A major tidal exchange doesn’t always end in catastrophe,” Ozkan-Haller said. “The Oregon coast has seen a lot of extremes over the years. But these are very high tides, followed by very low tides – and if a storm should happen to hit, it could be interesting.”

And if nothing happens in November, stay tuned. The same scenario will repeat itself in December.

Date High Tide/Time Low Tide/Time

Friday, Nov. 23 10.3 feet (10:04 a.m.) -1.6 feet (5:09 p.m.)

Saturday, Nov. 24 10.6 feet (10:48 a.m.) -2.1 feet (5:57 p.m.)

Sunday, Nov. 25 10.6 feet (11.33 a.m.) -2.2 feet (6:45 p.m.)

Monday, Nov. 26 10.3 feet (12:21 p.m.) -2.0 feet (7:35 p.m.)

Saturday, Dec. 22 10.5 feet (9:30 a.m.) -1.7 feet (4:59 p.m.)

Sunday, Dec. 23 10.6 feet (10:30 a.m.) -2.0 feet (5:48 p.m.)

Monday, Dec. 24 10.6 feet (11:20 a.m.) -2.0 feet (6:35 p.m.)

Tides Based on NOAA Predictions

A chart of tide table predictions for 2007 and 2008 is available on the OSU Hatfield Marine Science Center website at: http://hmsc.oregonstate.edu/weather/tides/tides.html.

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Tuba Ozkan-Haller,
541-737-9170

Scientists Mull Ecological Impacts of Wave Energy Projects

NEWPORT, Ore. – As public interest in wave energy technology increases, scientists are beginning to explore potential ecological implications that may arise from the creation of wave energy parks along the West Coast.

A recent workshop at Oregon State University’s Hatfield Marine Science Center raised many questions, participants say, and outlined important areas of research and outreach to address.

“Right now, the wave energy technology is ahead of the related ecological research,” said George Boehlert, director of the Hatfield Center and a professor of fisheries and wildlife at OSU. “It is important to begin addressing these questions because the potential benefits from a clean, renewable energy source like ocean waves are enormous.”

The workshop afforded many scientists their first exposure to planned deployments of wave energy-collecting devices and the technology that will make it possible.

“The extraction of wave energy has the potential to alter patterns of currents and sand transport in the nearshore environment,” said Paul Komar, professor emeritus in OSU’s College of Oceanic and Atmospheric Sciences. “In our discussions, however, we outlined some interesting approaches that may address this issue.”

A full report on the scientists’ initial analysis of ecological challenges relating to wave energy will be available early in 2008, Boehlert said.

More than a dozen different wave energy projects are in the research and development phase along the West Coast, and new technologies developed by researchers in OSU’s College of Engineering and elsewhere suggest that wave-generated electricity may be feasible both technologically and economically. OSU is recognized as the country's top academic center for wave-power research. The university is building a national wave-energy research and demonstration facility off the coast and an indoor lab to simulate ocean conditions.

The State of Oregon recently made a $4.2 million investment aimed at developing “responsible wave energy,” according to Gail Achterman, director of the Institute for Natural Resources at OSU and the university’s representative on the board of the newly formed Oregon Wave Energy Trust.

“Responsible development means assuring that the ecological effects are understood and addressed, and that coastal communities are fully engaged in the decision-making process to assure that wave energy development complements existing ocean uses,” Achterman said.

Boehlert points out that potential ecological impacts of wave energy may depend on the size, location and structure of the “parks” that would house a series of buoys.

“Ecological sensitivity is greatest closer to shore – say, out to an ocean depth of about 40 meters – and that also is a critical area economically in terms of crabbing and other fisheries,” Boehlert said. “Whether that aligns with the optimal locations for a wave energy facility is something that will have to be determined.”

Among the other questions posed by researchers:

• Will the size of wave energy parks affect local water circulation and currents, as well as the migration of crab, salmon and whales?

• Will the noise from the buoys have an impact on marine creatures depending on acoustics, from herring to whales?

• What impact, if any, will energy parks have on species that use electromagnetic field sensing for orientation or feeding, including salmon, crab, sturgeon, sharks and rays?

• Can the buoys and mooring lines be constructed to avoid entanglement of seabirds above the surface, and turtles, whales and other creatures underwater?

“Many of these questions are similar in nature to concerns raised when large electrical power lines started criss-crossing the terrestrial landscape,” said Greg McMurray of the Oregon Department of Land Conservation and Development and a member of the workshop steering committee. “The connectivity issues are similar, but the animals’ life histories and their habitats are a bit different.”

Boehlert says the workshop was intended to develop a general conceptual framework of the physical and biological relationships that can be applied to evaluate specific wave energy projects. The next step, he says, is to synthesize their discussion and create a research agenda that can address some of the concerns.

“It’s important to note that the scientists are not taking a stand ‘for’ or ‘against’ wave energy development,” Boehlert pointed out. “As ecologists, we strive for better understanding of the potential impacts of change, whether they are human-induced or natural.”

The Hatfield Marine Science Center workshop was supported by numerous state and federal agencies, industry and others.

More information about the workshop is available at http://hmsc.oregonstate.edu/waveenergy.

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George Boehlert,
541-867-0211

OSU's Newport Center hosts talk on El Nino and global warming

NEWPORT - "Erosion of the Oregon Coast: The Roles of El Nino and Global Warming" is the topic of a talk on Saturday, Feb. 22, at Oregon State University's Mark O. Hatfield Marine Science Center in Newport.

The 60-minute talk by Paul Komar, emeritus professor of Oceanic and Atmospheric Sciences at OSU, is free and open to the public and starts at 1:30 p.m. The center is located at 2030 S. Marine Science Drive. For information, call 541-867-0271.

Komar is the author of numerous books and articles dealing with beach processes and sedimentation, including a 1998 work, "The Pacific Northwest Coast: Living With the Shores of Washington and Oregon."

His latest research focuses Oregon coastal erosion, longshore current and sand transport on beaches, and modes of sediment transport in rivers. He earned his undergraduate degree at the University of Michigan and his doctorate at the Scripps Institution of Oceanography in La Jolla, Calif.

Komar's lecture is offered in conjunction with the Hatfield Marine Science Center's traveling exhibit, "The Big One: Earthquakes in the Pacific Northwest."

Source: 

OSU HMSC 541-867-0271

Workshops teach fishing industry to market directly

NEWPORT - A series of workshops will teach commercial fishers and seafood processors to keep their businesses afloat by building new markets and adding value to their catches.

The one-day session will be offered in six Northwest coastal cities. The series is sponsored by the Women's Coalition for Pacific Fisheries (WCPF) in association with Oregon and Washington Sea Grant. It is designed to help commercial fishers learn about direct marketing.

Each workshop will introduce marketing concepts, including branding and seafood quality. It will also teach participants the process of developing a marketing plan. Case studies from the commercial fishing industry will offer an inside look at direct marketing strengths and challenges within the industry.

Registration deadlines are Feb. 18 for the sessions in Washington and Feb. 25 for those in Oregon. Admission to the workshops is free to members of WCPF and $10 for non-members. To register for the sessions in Oregon, contact Ginny Goblirsch, 541-265-3463, or ginny.goblirsch@oregonstate.edu. For Washington workshops, contact Sarah Fisken, 206-543-1225, or sfisken@u.washington.edu. An online registration form is at http://wcpf.oregonstate.edu.

Quentin Fong, a seafood marketing specialist and associate professor of fisheries at the University of Alaska-Fairbanks, will lead the workshops. Fong recently conducted a similar workshop series for eight communities in Alaska.

"Our commercial fishermen and processors face enormous pressure from foreign suppliers of fish and shellfish," Fong said. "This has had serious effects on domestic fisheries, especially within small coastal communities where livelihoods are dependent on the bounty of the sea."

Fong believes there is hope for commercial fishermen and their communities - if they can change their ways of doing business. "There's no easy fix," he said. "Usually a series of steps will make the difference between success and failure."

All workshops begin at 8:30 a.m. The afternoon will be devoted to specific questions by program participants. The schedule:

  • Feb. 25: Marina Conference Center, Makah Marina, Neah Bay, Wash.
  • Feb. 27: Squalicum Boathouse, 2600 Harbor Loop, Bellingham, Wash.
  • March 1: Nordby Conference Center, Nordby Building, Fishermen's Terminal, 1711 W. Nickerson Street, Seattle, Wash.
  • March 3: Duncan Law Seafood Consumer Center, 2001 Marine Drive, Astoria, Ore.
  • March 5: Englund Marine, 800 S.E. Bay Boulevard, Newport, Ore.
  • March 7: Best Western Brookings Inn, 1143 Chetco Ave., Brookings, Ore.

Other sponsors of the workshops include the Alaska Sea Grant College Program and the OSU-Shorebank Enterprise Pacific Partnership.

Source: 

Ginny Goblirsch, 541-265-3463

Research finds life 1,000 feet beneath ocean floor

CORVALLIS, Ore. - A new study has discovered an abundance of microbial life deep beneath the ocean floor in ancient basalt that forms part of the Earth's crust, in research that continues to expand the realm of seemingly hostile or remote environments in which living organisms can apparently thrive.

Scientists from Oregon State University and several other institutions conducted the research off the coast of Oregon near a sea-floor spreading center on the Juan de Fuca Ridge. The findings will be published Friday in the journal Science.

In 3.5 million-year-old crust almost 1,000 feet beneath the bottom of the ocean, researchers found moderately hot water moving through the heavily-fractured basalt. The water was depleted in sulfate and greatly enriched with ammonium, suggesting biological activity in a high-pressure, undersea location far from the types of carbon or energy sources upon which most life on Earth is based.

It was one of the most precise biological samplings ever taken from deep under the ocean floor, scientists say.

"This is one of the best views we've ever had of this difficult-to-reach location in the Earth's crust and the life forms that live in it," said Michael Rappe, a research associate at OSU. "Until now we knew practically nothing about the biology of areas such as this, but we found about the same amount of bacteria in that water as you might find in surrounding seawater in the ocean. It was abundant."

According to Steve Giovannoni, an OSU professor of microbiology and one of the co-authors of the publication, the work represented a highly complicated "plumbing job," among other things. It took advantage of an existing hole and pipe casing that had been drilled previously in that area by the Ocean Drilling Program, through about 825 feet of sedimentary deposits on the ocean floor and another 175 feet of basalt, or hardened lava about 3.5 million years old. (more)

Using the existing casing, scientists were able to fit an experimental seal and deliver to the seafloor, for testing and characterization, the crustal fluids from far below.

"People have wondered for a long time what types of organisms might live within Earth's crust," Giovannoni said. "This has given us one of the best looks we've ever had at that environment."

The researchers found organisms apparently growing without the need to consume organic molecules, as does most life on Earth. Instead, they processed carbon dioxide and inorganic molecules such as sulfide or hydrogen.

DNA analysis of these microbes suggested they are closely related to known sulfate and nitrate "reducers" that are common in other environments. The level of biological activity was sufficiently high that ammonia levels in the subsurface samples were 142 times higher than those in nearby seawater.

"As more research such as this is done, we'll probably continue to be surprised at just how far down we can find life within the Earth, and the many different environments under which it's able to exist," Rappe said.

The deep ocean crust, the researchers said, is an immense biosphere in its own right that covers most of the Earth.

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Stephen Giovannoni, 541-737-1835

New Study: Predators Help Stabilize Marine Fish Populations

CORVALLIS, Ore. - Predators - and not competition within a species - are the primary source of population control and regulation in marine fish, a new study concludes. Overfishing of predatory species, which "appears to be rampant worldwide," runs the serious risk of destabilizing other marine species and disrupting marine biodiversity, researchers said in a report in the professional journal Ecology.

The findings contradict some of the basic approaches of modern fish management, which assume that competition between fish within a species is much more important in regulating populations.

The research was done by Mark Hixon, a professor of zoology at Oregon State University, and Geoffrey Jones of James Cook University in Australia. They examined kelp forests and coral reefs around the world, and concluded that predators are the dominant force in regulating abundance of their prey.

"These findings are important because they show that sustaining fisheries requires the help of predators," says Hixon. "Predators act to keep the abundance of their prey from fluctuating wildly, thereby promoting stability of prey populations fished by humans. Unfortunately, predatory fishes themselves are being overfished, so the populations of their prey may also become destabilized."

Hixon and Jones reviewed a dozen studies, including several of their own, in which scientists have experimentally removed predators from reefs in the ocean and observed that the mortality of their prey is no longer regulated. In practice, they said, populations of fish species are probably controlled by a combination of factors acting together, including predation, recruitment, habitat structure, ocean conditions and sometimes competition.

The research is supportive of the new trend towards "ecosystem-based management."

"John Muir had it right a hundred years ago," Hixon said. "Muir said 'When we try to pick out anything by itself, we find it hitched to everything else in the universe.' It is time to start managing our living marine resources from this holistic perspective by conserving marine predators."

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Mark Hixon, 541-737-5364

Despite Indian Ocean Warning, Northwest Still Not Prepared for Potential Tsunami

ASTORIA, Ore. - Nearly one year has passed since the devastating Sumatra earthquake and tsunami and despite that stunning wakeup call, Pacific Northwest residents are ill-prepared and even dismissive of the danger presented by the offshore Cascadia Subduction Zone.

During the last 10,000 years, there have been at least 23 earthquakes of magnitude 8.5 or higher off the Northwest coast, scientists say, and the threat from a major event and subsequent tsunami is very real - and probably overdue.

Yet education and outreach efforts have met with mixed results that vary individual by individual, and community by community, says Patrick Corcoran, coordinator of the Oregon State University's Sea Grant Extension Coastal Storms Program.

"People tend to either be dismissive of the danger, or fatalistic about it," he said. "Both are exactly the wrong approaches to take."

During the past several months, Corcoran has begun working with coastal communities in Oregon and southwest Washington to educate them about the danger of a subduction zone earthquake and tsunamis. Scientists say the Cascadia Subduction Zone is remarkably similar to the terrain in the Indian Ocean that led to the 2004 Sumatra quake and such devastation could occur in the Pacific Northwest.

Though some education progress has been made in a general sense, Corcoran says, people still don't know enough about how earthquakes and tsunamis could directly affect them.

"If you live in tornado country, you know to get into your basement with your radio and ride it out," Corcoran said. "You do it every year. But people living along the coast for the most part have no idea if they're in the inundation zone, they have made no plans on evacuating the family, and they haven't even identified a meeting place. In short, few families have any kind of communication plan."

Though signage along the coast has improved and siren systems have been installed, too many residents are unaware of what would happen should an earthquake and tsunami strike, Corcoran says.

"The general scenario played out is that a disaster would happen at 6 p.m. with the family gathered around the dinner table," he said. "No one thinks about what to do if the kids are at school, or Mom is running errands on the other side of a river over which lies a bridge that will collapse. There is a general feeling that someone will come to the rescue. But in a full-scale disaster as we saw in New Orleans with Hurricane Katrina - that may be some time."

In his presentations, Corcoran emphasizes the difference between a subduction zone earthquake, which occurs where tectonic plates collide, and crustal quakes, which are more frequent but usually less severe. He also differentiates between a distant earthquake - near Alaska or Japan, for example - that would give Northwest residents a few hours to evacuate, and a local event that may send a 60- to 90-foot surge of water inland within 30 minutes.

Though much of the attention has focused on tsunami preparedness, Corcoran says, few people think about the potential impact of a local magnitude 9.0 earthquake.

"People should not expect emergency services following a major earthquake," Corcoran said. "Local emergency responders will be overwhelmed and it will be difficult for others to help us. First, Highway 101 will be closed in hundreds of places because of earthquake-induced landslides, bridge failures and inundation damage, and major east-west highways would likewise be closed.

"Portland and the valley, being inland, would still be affected by the earthquake and have their own problems to address," he added. "It might be a few - to several - days before rescue efforts could reach local residents at the coast."

Corcoran says it is impossible for coastal communities to totally prepare for such a nightmare scenario, yet there are some things they can do that would help. One would be to publicize the location of assembly areas where evacuees should gather after a local earthquake.

"People need to know where 'safe' is," Corcoran said. "We have lots of signs telling us where to flee from, but no information on when to stop."

Communities also can continually educate themselves about earthquakes and tsunamis, focusing on the differences between distant and local events. Siren warnings, Corcoran says, should not be a cause for panic because they signify a distant event and local residents have time - often hours - to prepare.

"People who think sirens mean that tsunamis are imminent are dangerously misinformed," Corcoran said. "These are the people who jump into their cars and may cause accidents. A major local earthquake, on the other hand, is the warning that a tsunami may hit in as little as 15 to 30 minutes."

A third thing communities can do, Corcoran says, is to encourage families to develop a communication plan. During a distant event, phone lines may be jammed, causing inconvenience and stress. Families with homes in the inundation zones may not be able to return to them.

"A pre-determined meeting place would be very useful," Corcoran said. "During a local event, families need to understand that everyone will be on their own. They need to get themselves to safety first, and do not enter an inundation zone. Call a non-local relative and let them know you're okay."

Families and individuals, Corcoran said, should follow some simple guidelines:

 

  • Identify the "inundation" zones in your community, so you know where high water will hit, as well as the "safe" zones where you need to get to;

     

  • Develop a communication plan for your family - and even friends and neighbors - that includes agreement on local meeting place, and a distant relative or friend you can call if you get separated;

     

  • Educate children about what to do in an earthquake and tsunami, especially if they are away from home. Know where your children are taken in an earthquake during school hours.

    "Disaster kits may be helpful, but I'd suggest learning first aid and CPR," Corcoran said. "Knowing how to use a T-shirt to make a bandage is more useful than having an emergency bag you don't know what to do with - or is under the rubble that used to be your garage. And simply buying an emergency kit can lead to complacency and a feeling that you have things covered when you do not."

    It is up to individuals to take care of themselves and their families, Corcoran said. Local authorities cannot possibly help everyone at the same time following a local event. Don't anticipate that organized help will immediately and magically appear, he added.

    "There are no nannies during a major earthquake and tsunami."

  • Media Contact: 
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    Patrick Corcoran, 503-325-8573

    Oregon State Scientists to Deploy Underseas Listening Devices in Antarctica

    NEWPORT, Ore. - A team of scientists and educators from Oregon State University's Hatfield Marine Science Center in Newport has left for Antarctica on a research project to deploy an array of undersea hydrophones.

    These hydrophones, developed at the OSU center, will record the sounds of undersea earthquakes and volcanoes, moving ice sheets, and even the vocalizations from large baleen whales, according to Robert P. Dziak, an associate professor at the university who also works for the National Oceanic and Atmospheric Administration.

    "This new ocean-sensor technology will use cold water-capable, deep-ocean hydrophones to provide the first-ever comprehensive record of the sounds of Antarctica," Dziak said. The team will recover the hydrophones on a follow-up cruise in 2006.

    Bill Hanshumaker, a Sea Grant marine educator, is accompanying the researchers and will post progress reports online beginning Dec. 5. The team will post images, sound files and logs of the trip as part of the project, which is called "Sounds of the Southern Ocean." The cruise, a component of NOAA's Ocean Explorer program, will conclude on Dec. 13.

    Project updates will be posted on the cruise website, http://oceanexplorer.noaa.gov/explorations/05sounds/welcome.html, and on an Oregon Sea Grant website, http://seagrant.oregonstate.edu/extension/hanshumaker/ocean_explorations.html.

    The Southern Ocean surrounds Antarctica and serves as a conduit between the Atlantic, Pacific and Indian oceans. Yet because of severe climatic conditions, much of this ocean basin remains unexplored, Dziak said.

    "Polar regions play key roles in the global environment and one goal of our project is to document linkages between changes in the Antarctic ice sheet and the volcano-tectonic seafloor processes in the region," Dziak said.

    After arriving in Punta Arenas, Chile, the project team is scheduled to fly to King Sejong, a Korean research station, on the Barton Peninsula of King George Island on Dec. 3. From there, they will board a Russian research vessel, the Yuzhmorgeologiya, Dec. 6, which will take them to the Bransfield Strait for deployment and testing of the hydrophones.

    The research team also includes Haru Matsumoto, a NOAA engineer who helped develop the hydrophones and will coordinate the hydrophone installation; and Sara L. Heimlich, a NOAA marine mammal specialist, who will conduct visual and acoustic surveys of marine mammals. Both work at OSU's Hatfield Marine Science Center.

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    Bill Hanshumaker, 541-867-0167

    Scientists Hone in on Earthquake 'Pulses' to Help Predict Tsunami Impact

    CORVALLIS, Ore. - The magnitude 9.2 earthquake that triggered a devastating tsunami in the Indian Ocean in December of 2004 originated just off the coast of northern Sumatra, but an "energy pulse" - an area where slip on the fault was much greater - created the largest waves, some 100 miles from the epicenter.

    Seismologists have mapped these energy pulses for Sumatra and are trying to learn more about them to predict better when and where tsunamis may occur. They also hope these pulses will help them gain a more comprehensive understanding of the earthquake history of the Cascadia Subduction Zone off the Pacific Northwest Coast of the United States.

    "Understanding the nature of these pulses could be critical because it could mean the difference between 15 minutes and 30 minutes in a tsunami warning," said Chris Goldfinger, an associate professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and one of the leading experts in the world on the Cascadia fault zone.

    "It seems that the largest Cascadia earthquakes have three pulses," Goldfinger added, "and core data show that more than half of the earthquakes in the Cascadia Subduction Zone are of this large type that appear to generate three rupture sequences."

    Earthquake "pulses" are releases of energy from areas of high slip along the main fault. When a subduction zone earthquake occurs, the tectonic plates that have locked for centuries suddenly release. An area of ocean floor that may be as wide as 50 miles, and as long as 500 to 600 miles, can suddenly snap back, causing a massive tsunami. As that energy radiates down the fault, it is concentrated in certain areas, Goldfinger said. The severity of the tsunami in any locality depends on how much energy is released, and what the undersea terrain is like.

    The energy pulses, which are part of the earthquake sequence and take place almost immediately, differ from aftershocks that may occur hours, days, weeks or months after the original earthquake. In fact, the December Sumatra quake was followed by an 8.7 tremor in March and, though it occurred well to the south, "looks to have been directly triggered by the stress of the December event," Goldfinger said.

    "And there have been a lot of aftershocks since," he added.

    Goldfinger said it appears the Indian Ocean fault is rupturing in a southerly direction and that Padang, the capital of West Sumatra, may be next in line for a major earthquake.

    But whether that quake takes place in weeks or years remains to be seen. Though Padang's last major quake was about 200 years ago, the increased stress on the fault makes it likely that the lag between events will be much shorter.

    "When you load the stress on a fault, it shortens the time between quakes," Goldfinger pointed out. "It's like putting a sheet of glass between two sawhorses - and then sticking a cinder block in the middle of the glass. It may not break right away, but the stress builds rapidly."

    Comparatively little is known about the long-term tectonic history of the Indian Ocean - at least, compared to the Cascadia Subduction Zone, scientists say. Goldfinger has been able to identify 23 major earthquakes off the Pacific Northwest coast during the past 10,000 years through analysis of sediment deposits. At least 16, and possibly 17, of those quakes have ruptured along the entire length of the Cascadia Subduction Zone, requiring an event of magnitude 8.5 or better.

    When a major offshore earthquake of that magnitude occurs, "you get ground acceleration of a couple of G's," Goldfinger pointed out. "Mud and sand begin streaming down the continental margins, and out into the undersea canyons. Walls fail. And the sediments run out into the abyssal plain. The impact is much, much greater than you can get from any storm - or even a small magnitude quake."

    Those coarse sediments - called turbidites - stand out from the finer particulates that accumulate on a surprisingly regular basis in between major tectonic events. By studying core samples from submarine channels in various locations along the subduction zone, Goldfinger and his colleagues have been able to create a 10,000-year timeline of huge earthquakes that provide sobering evidence that the Northwest is due for a major event. Going back farther than 10,000 years is proving to be difficult.

    "The sea level used to be lower and rivers emptied directly into offshore canyons," he said. "You couldn't differentiate between storms and earthquakes. But once sea levels rose, the river sediments were trapped on the shelf and upper slope, leaving a near-perfect earthquake record farther out."

    Goldfinger said that evidence suggests turbidites might record earthquake pulses, but more testing is needed in Sumatra, where "we have good recordings of the earthquake."

    What the Indian Ocean lacks is the same long-term sediment analysis that has been done in the Cascadia zone, says Goldfinger, who adds that conditions there are ideal for such research. He and a team of scientists from Indonesia and India are planning a series of cruises over the next several years to take core samples from the Indian Ocean in an attempt to map the tectonic history of the region.

    "If anything, the Indian Ocean is even better suited than Cascadia for this kind of core analysis because there is a huge basin between the rivers and the deep ocean that keeps the terrestrial sediments close to land," Goldfinger said. "We should clearly be able to see the December and March turbidites stacked on top of the finer sediments."

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    Chris Goldfinger, 541-737-5214

    One Year Later: Huge Tsunami Spurred Progress, Revealed Needs

    CORVALLIS, Ore. - The catastrophic tsunami that struck Indonesia and East Asia almost a year ago has done much to heighten the interest, research programs and preparations in the United States for events of this type, but experts say there are areas that need more attention and challenges yet to be met.

    Dec. 26 will mark the first anniversary of the tsunami that claimed the lives of about 275,000 people and struck with waves up to 100 feet high, one of the deadliest disasters in modern history.

    Since that time, Congress has worked on legislation that would enable the National Oceanic and Atmospheric Administration to spend $35 million per year for a major expansion and improvement of warning systems in the United States, and support other smaller research or disaster planning initiatives around the nation in a U.S. Tsunami Warning Network.

    But scientists at Oregon State University, which operates one of the world's leading tsunami research facilities, say more studies are necessary on expected wave behavior at specific coastal locations, the probable impact on structures and measures that could be taken to reduce casualties and damage.

    "The significant support to NOAA is a good sign that the risks of tsunamis are finally being taken more seriously," said Harry Yeh, the Edwards Professor of Ocean Engineering at OSU and a leading international expert on tsunamis. "The majority of that will be focused on early detection systems in the Pacific Ocean and Caribbean Sea to improve warnings about tsunamis originating from distant locations."

    However, according to Yeh and Dan Cox, an associate professor and director of the Hinsdale Wave Research Laboratory at OSU (http://wave.oregonstate.edu/), there are still pressing educational, research and planning needs. They have special urgency in the Pacific Northwest - the North American location most vulnerable to a tsunami that would strike with little forewarning -- from the nearby Cascadia Subduction Zone.

    "Much of our current approach to tsunami preparation is about warning systems and getting people out of the way," Cox said. "In some cases, that's appropriate. But there are also serious questions about how practical it will be to evacuate large numbers of people in towns that are accessible by a two-lane road. We will have only a very short time - 20 to 30 minutes, not hours - in the case of the Cascadia Subduction Zone tsunami."

    "So we should consider other approaches to protect public safety like designing hotels or parking garages that would be strong enough and high enough to provide a local haven for people who would not be able to reach higher ground," he said. "The emphasis on warning systems also does little to help the personnel responding to the disaster. For example, will debris make some roads inaccessible?"

    Studies addressing those topics are conducted at OSU in its Tsunami Wave Basin, a sophisticated, $4.8-million facility in which scientists can simulate, in miniature, the forces and behavior of waves as they approach a coastline with various features and types of undersea topography. Researchers all over the world use the facility, the largest of its type in the world, for advanced tsunami research.

    And last year, both Yeh and OSU civil engineering professor Solomon Yim did field research in East Asia on the behavior and impacts of the tsunami there.

    "One big change we need is better interdisciplinary research in this field," Yeh said. "We have to get seismologists and marine geologists talking to civil engineers, so we can get better tsunami-source information to propagation models for prediction of coastal effects. We need to have social scientists working with disaster planners so that evacuation plans are realistic and actually work in the short time frame we may have available. We soon plan to begin research on the social dynamics of this problem."

    In Oregon, Yeh said, there's also an inadequate analysis of the specific marine terrain at various coastal towns and the implications that would have for a tsunami wave run-up. Much more work also needs to be done on the impacts of large, heavy debris sloshing back and forth in repeated tsunami waves - a problem vividly illustrated in the enormous structural damage caused by the East Asian tsunami.

    With more research, it might be possible to construct at least some future buildings with methods that would better resist damage or destruction by tsunami waves, the OSU researchers say. The Oregon Sea Grant Program has provided a two-year, $170,000 grant to support fundamental research in this area.

    "The number of fatalities from earthquakes in the U.S. is actually very low, because a long time ago we realized the dangers they pose and changed our building codes to start planning for them," Cox said. "But we don't have comparable building codes for tsunami-resistant structures."

    The major tsunami of last year has also caused a surge of student interest in study and research on this field, the OSU experts said, that could be tapped to better prepare the scientists of the future who will continue to deal with the threats posed by these catastrophic events.

    Some experts say there is a 10-14 percent chance that there could be a massive earthquake and tsunami on the Cascadia Subduction Zone within 50 years. The last such event is believed to have happened in 1700, and 23 major earthquakes have been recorded on this fault zone, which runs from northern California to Vancouver Island, in the past 10,000 years.

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