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Tsunami research;

topic posted Wed, February 22, 2006 - 1:43 AM by  Bobs
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The Math Of Deadly Waves

by Staff Writers
Hamilton, Canada (SPX) Feb 21, 2006
When Walter Craig saw the images of the devastating 2004 Boxing Day Indian Ocean tsunami he felt compelled to act. So he grabbed a pencil and envelope and started calculating. A little more than a year later, the mathematical analyst says that mathematics has a role to play in washing away misconceptions and myths about these deadly waves – and potentially saving lives.
"Predicting earthquakes is a grand challenge problem that's presently beyond us. But predicting a tsunami's potential based on these earthquakes is a doable problem and I think mathematicians can play an important role in this," says Dr. Craig, the Canada Research Chair for Mathematical Analysis and its Applications, at McMaster University in Hamilton, Canada.

"Mathematics is particularly well suited to defining the possibilities and limitations for a tsunami early warning system," says Dr. Craig. It's a conviction that's prompted him to co-organize the symposium on Tsunamis: Their Hydrodynamics and Impact on People at the annual meeting of the American Association for the Advancement of Science (AAAS) in St. Louis, on Sunday, February, 19.

Dr. Craig studies the mathematical theory of wave equations that are derived from physics. In collaboration with colleagues he has applied these theories to scientific problems large and small, from the quantum mechanical oscillations of electrons to the cosmic waves that rippled through the newborn universe. But rarely, he says, does the mathematics of wave propagation meet a subject so full of immediate human importance as with understanding rogue waves.

Mathematics, he says, has a key role to play in dispelling mistaken assumptions about these waves. One such popular belief is that a tsunami's first wave surge is always the biggest.

"It's not necessarily the biggest crest in front," he cautions. "For example, in Sri Lanka the biggest crest was the third or fourth." In one case, he says, a vacationing British geologist at one Sri Lankan resort noted the initial modest, non-destructive surge and warned staff and tourists to clear the beach before the arrival of the larger, deadly surges.

Dr. Craig says that mathematical modelling of the Indian Ocean tsunami showed it to be close to what he calls a "classical wave packet" – the wave behaved in a manner very close to that predicted by mathematical theory. It followed the pattern of a group of waves travelling together as well as evolving in form as they crossed the ocean basin.

Because of differences in depth, the evolution of a tsunami is different in different ocean basins. For example, the Boxing Day tsunami travelled twice as fast in the deeper Indian Ocean than in the Andaman Basin. Tsunami waves are distinguished from ordinary wind-generated ocean waves by their great length between peaks, often exceeding 200 kilometres in the deep ocean, and by the long amount of time between these peaks, ranging from 15 minutes to an hour.

It's the length and width of tsunamis, rather than their at-sea height that reveals their massive power. The Indian Ocean tsunami had a crest length of about 1,200 kilometres. The surges that inundated the Sri Lankan coast were parts of waves that were a stunning 100 kilometres from crest to trough, but in mid-ocean were less than one metre in amplitude.

"It's amazing to think about this. Even if the wave is only a metre high at mid-sea, this is a huge amount of water and it gives a sense of how much energy it's carrying," says Dr. Craig.

Another widely held belief about tsunamis that gets washed away with mathematical modelling is that the surge is always preceded by the tide going abnormally far out.

"This only happens about half the time," explains Dr. Craig. "It depends on the wavelength and whether it's the trough or crest of the wave that reaches shore first. In half the cases it's the surge that arrives first."

Dr. Craig acknowledges that for the most part geologists and tsunami experts have a strong practical understanding of how these giant waves behave. But, he says, given the paucity of real-world data on tsunamis, there are still many outstanding questions.

"To a first order of approximation the current modelling of a tsunami's evolution in mid ocean is very good," says Dr. Craig. "Nonetheless, there is much less known about the generation of tsunami waves, and about the amplification effects as they impact on coastal areas. These are not easy mathematical problems. Experimentally they're not seen very often, so it's still a question as to whether we're using the right equations to study them."

He's presently begun work with McMaster University mathematics colleagues Drs. Bartosz Protas and Nicholas Kevlahan to apply mathematical tools from meteorological forecasting to understand the generation of large tsunamis from major earthquakes. For example, some earthquakes generate large waves, while others of the same magnitude produce little or no wave response. Their approach will use hindcasting techniques – looking back over previous patterns to understand how we arrived at present conditions – to develop predictive computational models for tsunami sources.

While better advanced warning systems can help in many cases, Dr. Craig says his immersion in tsunami science has shown him that a tsunami's speed and power sometimes can defy an early warning system. With a wave traveling at 700 kilometres an hour, his advice is, "If you feel an earthquake, go to higher ground."

Related Links
Natural Sciences and Engineering Research Council
McMaster University


www.terradaily.com/reports/...aves.html
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Bobs
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  • Re: Tsunami research;

    Wed, March 8, 2006 - 11:34 PM
    Posted on: Tuesday, March 7, 2006
    All tsunami signs point to Hawai'i


    By Jan TenBruggencate
    Advertiser Science Writer



    While the five most severe tsunamis to hit here in the past 60 years have come from three areas — Chile, Russia's Kamchatka region, Alaska and the Aleutian Islands — Hawai'i is at risk from almost every point of the compass.

    Emergency preparedness officials maintain that no Hawaiian shoreline is safe from a tsunami. And just because a tsunami hasn't hit Waikiki or Wai'anae in a century or more is no reason to feel secure there.

    "If it's a sheer cliff at least 50 feet high and you've got your house up there, you're probably all right," said Daniel A. Walker, retired University of Hawai'i seismologist and O'ahu Civil Defense tsunami adviser.

    Otherwise, you should have a tsunami evacuation plan. The Dec. 26, 2004, Indian Ocean tsunami, that killed or left missing more than 220,000 people in 11 countries, underscored that.

    "It was a wake-up call. It rattled our cage," Walker said.

    Hawai'i's disaster-management experts are now taking a fresh look at quake zones in areas that have not traditionally generated Pacific-wide events.

    "The issue of a large event in the southwest Pacific or the western Pacific is something we are addressing as we speak," Walker said.

    Charles "Chip" McCreery, director of the Pacific Tsunami Warning Center, said those regions include the area around Japan and the region from Tonga to the Solomon Islands and Papua New Guinea. He said he also is keeping an eye on the West Coast from Northern California to British Columbia.

    "Every 300 to 500 years, there's a major earthquake there (along the West Coast). The next time that pops off, it will be a big problem for those areas, but the tsunami will hit Hawai'i," he said.

    With seismically active zones rimming the Pacific Ocean, McCreery said, "We're probably at risk from anyplace."

    Tsunamis that have caused damage in the Islands in recent generations have come from the Aleutians (1946 and 1957), Kamchatka (1952), Chile (1960) and Alaska (1964), and from an earthquake near Kalapana on the Big Island (1975). A 1994 earthquake in Japan's Kuril Islands prompted a statewide coastal evacuation in Hawai'i, but the wave measured only a few inches locally.

    Hawai'i's tsunami experts meet regularly at O'ahu Civil Defense offices, where they're working to anticipate the next tsunami by studying seismic scenarios. They're also reviewing problems that hampered the response to the Indian Ocean tsunami, the Civil Defense response to Hurricane Katrina and a confusing tsunami warning last June in California.

    On June 14 last year, a quake of about 7.4 magnitude shook at 7:51 a.m. off Northern California. Within minutes, the Alaska-based West Coast/Alaska Tsunami Warning Center issued a tsunami warning for the region. The Hawai'i-based Pacific Tsunami Warning Center, meanwhile, issued a notice that there was no Pacific-wide tsunami. Consequently, emergency agencies issued conflicting reports — some beach areas were evacuated while others were told there was no threat. In addition, some emergency communications equipment was found to be inoperative.

    In the end, the tsunami turned out to be too small to cause damage. But confusion surrounding the incident alarmed Hawai'i Civil Defense officials, although they point out that Hawai'i's own warning system is different.

    "Part of the problem is that they haven't practiced any of that, and we do," said Jeanne Johnston, earthquake and tsunami program manager for state Civil Defense in Hawai'i.

    Hawai'i emergency officials take their tsunami information from just one source: the Pacific Tsunami Warning Center. Communication lines between state and county emergency centers are tested regularly, and personnel train in disaster scenarios frequently, Johnston said.

    In terms of providing warnings, Hawai'i is in better shape than it's ever been, largely because of an infusion of cash in response to the Indian Ocean disaster. McCreery's staff is now increasing from eight members to 15, which will permit 24-hour staffing of warning-center offices. And there also is an increase in detection equipment already in place or soon to be installed on land and in the oceans around the Islands, he said.

    One of the key pieces of equipment is a buoy attached to a seafloor sensor that detects the strength of a passing tsunami. Before the Indian Ocean tsunami, there were six buoys, known as Deep-ocean Assessment and Reporting of Tsunami or DART buoys. There are now 10 and there will be a total of 32 in two years — covering the ocean floor from all directions that pose threats to Hawai'i.

    "They'll be out there to cover all the major seismic zones in the Pacific," McCreery said.

    The biggest tsunami response issue in Hawai'i, several emergency officials said, is the readiness of the civilian population.

    Kaua'i Civil Defense coordinator Mark Marshall said he is sure the emergency system will be able to inform the population of a pending disaster but is not sure the public will respond appropriately.

    Tsunami evacuation maps are in the front of Hawai'i phone books, along with recommendations for contents of emergency kits and other disaster response information. Still, emergency preparedness officials worry that residents may not use information at their fingertips.

    Marshall said that in a 2003 Japan tsunami, despite a robust emergency response mechanism and comparatively frequent emergencies, a large proportion of the population failed to evacuate after being warned.

    Johnston said, "People are waiting for the government to protect them, but they need to be responsible for their own families."

    Reach Jan TenBruggencate at jant@honoluluadvertiser.com.

    www.honoluluadvertiser.com/asse...7.GIF


    www.honoluluadvertiser.com/apps...ticle
  • Re: Tsunami research;

    Wed, October 11, 2006 - 11:56 PM
    TIDAL WAVES IN EUROPE?
    Study Sees North Sea Tsunami Risk
    By Axel Bojanowski

    The last known tsunami to hit Europe was over 8,000 years ago. But new research reveals that there have been a number of deep-sea earthquakes since then, and that a landslide along the continental slopes could pose a serious risk to the cities and towns on the North Sea coast.

    It was a catastrophe of apocalyptic proportions. An earthquake shook Norway's coast between Bergen and Trondheim about 8,150 years ago. The tremors ripped pieces of land the size of Iceland from shallow water and sent them crashing into the deep sea. Like a stone thrown into a pond, the landslide produced ripples of waves that spread at the speed of a train -- powerful tsunamis racing across the North Sea. Along the beaches of Scotland the waves were up to six meters (20 feet) high. Geologists have discovered a ravaged Stone-Age site there.

    Could something like this happen again? The environmental conditions in those days were different: 10,000 years ago the three-kilometer ice crust that had covered northern Europe during the Ice Age was beginning to melt. This released the earth's crust, which sometimes raised itself jerkily, quaking the earth. Since then the ground has calmed down, experts have believed until now. Strong shakes along the earth's tectonic plates in the seabed are rare, and these tend not to generate giant waves. For example on Jan. 24, 1927, there was a quake in the sea between Norway and Great Britain. On June 7, 1931, there was one between Denmark and Great Britain. And on Nov. 18, 1929, one in North West Scotland. A quake in the streets of Dover in 1580 was mentioned in Shakespeare's Romeo and Juliet. Otherwise, everything's been calm. Or so it seemed.

    Chronicles Reveal 16th Century Earthquakes

    Geologist Roger Musson of the British Geological Survey in Edinburgh has unearthed documents that paint a different picture. Several sources from the 16th century mention an earthquake on Sept. 19, 1508. "It was a great earthquake, not only in Scotland, but also, indeed, even the whole of England, which shook the churches especially, which was interpreted as an omen of the overthrowing of religion," wrote the Scottish Bishop of Ross, John Leslie.

    Obviously this was not one of the local tremors which often occur in Scotland and England, both then and now. This at least was the thesis put forward by Musson recently at the European Geosciences Union (EGU) conference in Vienna. He argues that the fact that churches "especially" affected points to a significant quake. Heavy quakes that occur far away tend to be more likely to cause high buildings such as church towers to move. The fact that no damage was reported would indicate that the source of the shock was deep in the seabed.

    Many years of research in libraries, church archives and old chronicles led Musson to further disturbing reports. Entries suggest that in 1089, 1508, 1607, 1686 and 1847 the seabed near Great Britain suffered severe quakes, the scientist writes in a study to be published soon.

    It seems that earthquakes not only occurred more frequently than had previously been thought, but that they were also stronger, Musson told SPIEGEL ONLINE. It is, however, difficult to prove -- as earthquakes along Europe's coasts have only been recorded with measuring instruments since the 1970s.

    Unstable Continental Slope

    Musson's archival discoveries have focused attention on northwestern Europe's continental slope. The underwater cliffs between shallow water and the deep sea off Norway's coast are 3,800 meters deep. Could a quake cause the sediment lying on the slope to slide -- just like 8,150 years ago?

    Norwegian scientists who have carried out years of research are certain that there is no danger of a landslide off the coast of Storegga. Most of the volcanic tephra had slid off during the giant landslide 8,150 years ago, Tore Kvalstad of Norway's Geotechnical Institute told SPIEGEL ONLINE.

    However, there has not been the same extensive research into the coasts north and south of the Storegga slope. A group led by Petter Bryn from energy company Norsk Hydro and Anders Solheim of the International Center for Geohazards in Oslo have researched Norway's west coast. The result: There were landslides in many places along the coast over the past million years.

    Most were significantly smaller than the one at Storegga. In 1999 researchers discovered traces of a violent landslide on Norway's north coast that is being surveyed now for the first time. A group led by Daniel Winkelmann and Wilfried Jokat of the Alfred Wagner Institute (AWI) in Bremerhaven reported in Geochemistry Geophysics Geosystems that the sand masses are of a similar strength to those in the Storegga landslide. The so-called Yermak Slide (also Hinlopen Slide) is assumed to have fallen into the deep sea around 30,000 years ago and caused tsunamis, according to the researchers.

    Dangerous Gaps in Knowledge

    Whether this could occur again depends upon the mix of sediment on the continental slope. There has been hardly any research into this deposit -- a gap in knowledge with possibly fatal consequences. The sediment could hide extensive layers of clay, which could act as a slick slope for a landslide. Steep layers of sand would be another cause for alarm, because even a light ground motion could cause them to move.

    Possibly the greatest elements of uncertainty are the so-called methanhydrates: gas-containing ice caps which keep the sand attached to the slopes like a kind of weak sticker. In the scientific journal Eos, Angus Best of the University of Southampton warns that if the water level or the temperature were to change, this "cement" could dissolve. An earthquake could also cause the volatile architecture to slide, says AWI researcher Wolfram Geissler.

    A computer model designed by Norwegian scientists shows the possible consequences of a mega-landslide. They have forecast the progression of a disaster: Minutes after the landslide 14-meter-high waves would hit Norway's coast, with fatal results, as many cities lie at sea level or in bays with sharply canted floors, where the waves would rise even higher. After three hours 20-meter-high breakers would crash onto the Shetland Islands. Two hours later the Faeroe Islands would be covered in waves of up to 14 meters high. After six hours, the tsunamis would still be six meters high, tearing along Scotland's beaches toward the coastal cities of Edinburgh, Aberdeen and Dundee. As they head southwards the waves would become smaller, the oscillating North Sea acting as a break.

    The model predicts that Germany's North Sea coast would only see light flooding -- but even elaborate computer models can be wrong.



    www.spiegel.de/internatio...819,00.html


    Wonder if they're aware of this little event? awesomenature.tribe.net/thread...9afbda6
  • Re: Tsunami research;

    Tue, November 14, 2006 - 2:04 AM
    Joining Forces To Predict Tsunamis

    by Staff Writers
    Paris, France (SPX) Nov 14, 2006
    Following a series of well documented natural disasters with grave human and economic consequences, the ability to predict these devastating events has once more come to the fore as a research priority for the European scientific community. This, amongst other things, is what leading scientists in ocean margin research came together to discuss at the recent EUROMARGINS conference in Bologna, Italy.
    Margins are the transition zones between the continents and the deep oceans. They are also often at the boundary between two tectonic plates.

    EUROMARGINS is a European Collaborative Research (EUROCORES) Programme coordinated by the European Science Foundation (ESF) and supported by science funding agencies in ten European countries.

    Tsunami warning system


    Tsunamis are large waves presenting extreme threats to coastal areas. The largest recorded tsunami, which hit Alaska in 1958, loomed to a height of 520m. They can come about as a result of continental landslides, rock falls, submarine landslides or earthquakes. In the 1990s, four tsunamis ravaged Nicaragua, Indonesia, Japan and Papua New Guinea causing the loss of 4,000 lives and of course no one can forget the total devastation brought about by the December 2004 Indian Ocean tsunami where 230,000 people lost their lives.

    The Gulf of Cadiz has a history of both tsunamis and earthquakes. In fact, the whole Southern area of the Iberian and the facing North African coast are considered high risk areas. As recently as 21 May 2003, a tsunami wave reaching three metres hit the Balearic coastline in just 20 minutes from its origin far out at sea. It took sea levels 24 hours to recover and twenty boats sank.

    Despite the Mediterranean being a high risk area, surprisingly, there is no tsunami early warning system in place. "Our goal is to develop an integrated system using earthquakes as a source of tsunami detection with a 20 minute maximum time frame for the alarm to sound," explains one of the conference's external guest speakers Stefano Tinti from the recently launched TRANSFER initiative.

    Tinti came to talk to the EUROMARGINS community about the first ever funded European project to look at tsunamis with the purpose of developing a tsunami early warning system. This effort is ground-breaking and aims to understand the tsunami process, contribute to tsunami hazard and risk assessment and, to develop strategies for risk reduction. Research generated from the EUROMARGINS community has helped to make this project possible.

    Developing models


    One of the EUROMARGINS Principal Investigators Miquel Canals from the Universitat de Barcelona described the area between Ibiza and Mallorca in the Mediterranean as being covered in calcified rock rich in pockmarks of different sizes. This gives the sea bed the appearance of a giant 'orange peel'. Some of these pockmarks are as deep as 50m and more than 1km in diameter. Canal also described submarine landslides in the region, like the one off the Ebro shelf (known as the Big 95) that affected a seafloor area four times that of the island of Ibiza.

    While the pockmarks are indicative of fluid migration under the seafloor and fluid escape at the seafloor, the landslides around the islands deserve further investigation to assess their tsunamigenic potential.

    "The characteristics of a tsunami depends primarily on the volume and initial acceleration of the released sediment as well as the water depth" explains Carl Bonnevie Harbitz from the Norwegian Geotechnical Institute (NGI) in Oslo.

    Harbitz and his colleagues at NGI and University of Oslo have developed models which can predict tsunamis caused by rock falls, submarine slides, earth quakes and even asteroid impacts. To validate and improve the models, Harbitz and his team have put much effort into back-calculating historical events.

    Using field observations from the 8200 BP submarine Storegga slide tsunami off Western Norway, the 1934 rockslide Tafjord tsunami and the 2004 Indian Ocean earthquake tsunami, the team has improved the reliability of their models. The complexity of the coastal region of the wave impact is also an important factor when developing reliability.

    Harbitz has applied this model to his native North Sea area and found that a possible future tsunami generated in for example the North Sea Fan area will start far off shore and will most likely not reach heights bigger than 1m by the time it reaches the shore.


    www.terradaily.com/reports/..._999.html
  • Re: Tsunami research;

    Tue, November 28, 2006 - 11:47 PM
    Giant 8,000-year-old tsunami is studied

    Italian scientists say geological evidence suggests a giant tsunami resulted from the collapse of the eastern flanks of Mount Etna nearly 8,000 years ago.

    The collapse of the volcano, located on Italy's island of Sicily, was studied by Maria Teresa Pareschi and colleagues at Italy's National Institute of Geophysics and Volcanology. They modeled the collapse and discovered the volume of landslide material, combined with the force of the debris avalanche, would have generated a catastrophic tsunami, impacting the entire Eastern Mediterranean.

    Simulations show the resulting tsunami waves would have destabilized soft marine sediments across the floor of the Ionian Sea. The authors, noting field evidence for such destabilization can be seen in other studies, speculate such a tsunami might also have caused the abandonment of a Neolithic village in Israel.

    The study -- entitled "The Lost Tsunami" -- appears in the current issue of the journal Geophysical Research Letters.


    www.physorg.com/news83960532.html
  • Re: Tsunami research;

    Sat, June 16, 2007 - 2:37 AM
    Oceanographers study effects of 2004 tsunami quake

    AO MAKHAM: A multinational group of oceanographers has completed a survey of the fault zone that caused the 2004 tsunami and early results show that the quake also caused a massive landslide.

    The R/V Roger Revelle, a 75-meter research vessel from the Scripps Institution of Oceanography in California, berthed at the Deep Sea Port at Cape Panwa yesterday after completing a 39-day study of the sea floor that involved coring of seabed sediments.

    The focus of the research, led by Dr Chris Goldfinger of Oregon State University, was the the Java Trench subduction zone off the coast of Sumatra, near the epicenter of the 9.3-magnitude earthquake that triggered the 2004 tsunami.

    The research team comprised 59 scientists, including oceanographers from Germany, Japan, Spain and Indonesia.

    Dr Goldfinger said initial results indicated that the research had detected evidence of the submarine landslide caused by the earthquake, but that the data need further analysis back in the US.

    While the research was useful, there is still no way to accurately predict or prevent tsunamis from occurring, Dr Goldfinger said.

    For this reason, a reliable early warning system must be installed in risk areas and people living in such areas must have confidence in it for it to be effective.

    In few days, the Roger Revelle will leave Phuket to begin its next mission: mapping a 4,000-kilometer volcanic ridge in the Indian Ocean known as the “90-East Ridge”, which is the longest of its type on earth.

    The research on the 50-day survey will be led by Dr Will Sager, a professor of oceanography at Texas A&M University.

    Scientists have believed for many years that the ridge formed naturally from rising magma from the mantle where the Indian Plate drifted northward into the Eurasian place, sequentially forming a line of volcanoes. That theory has come under criticism in recent years, so the mapping will try to determine how the ridge actually formed.

    Seismic techniques will be used to probe into the sediment layers.

    Another part of the research will involve using 19th-century dredging techniques to collect exposed volcanic rock samples along the ridge flanks, at depths from 2,000 to 4,000 meters. The rocks will then be analyzed onshore for chemical composition and age.


    www.phuketgazette.net/news/index.asp

  • Re: Tsunami research;

    Mon, June 18, 2007 - 3:59 PM
    Scientists study 'stealth' tsunami that killed 600 in Java last summer

    Though categorized as magnitude 7.8, the earthquake could scarcely be felt by beachgoers that afternoon. A low tide and wind-driven waves disguised the signs of receding water, so when the tsunami struck, it caught even lifeguards by surprise. That contributed to the death toll of more than 600 persons in Java, Indonesia.

    “The general assumption was that if you were near the coast where the earthquake took place, you would feel it and be able to run to higher ground,” said Hermann Fritz, first author of a new Geophysical Research Letters paper about the July 17, 2006 tsunami. “This event caught people by surprise and showed that it’s not always that simple.”

    The earthquake was slow rupturing, so it didn’t produce strong ground shaking on Java that might have alerted people on the beach, he explained.

    No local warning was issued for the tsunami waves, which arrived only tens of minutes after the earthquake. Fortunately, the event took place on a Monday. Had the massive waves hit the day before, which was a major national holiday, the popular beach would have been much more crowded – and the toll higher.

    “Warning systems typically don’t work very well for locations near earthquakes, where there are only tens of minutes between the earthquake and the tsunami’s arrival,” noted Fritz, a Georgia Institute of Technology assistant professor who led an inspection team to Java a week after the event. “It’s pretty much a spontaneous self-evacuation. You normally feel the earthquake or see the ocean withdraw. If you hear the noise in the last tens of seconds before it hits, then it’s just a matter of who makes it and who doesn’t.”

    The survey team, which included scientists from five different countries, interviewed survivors and studied evidence left behind by the tsunami, including debris fields. Beyond the quiet nature of the catastrophe, they discovered evidence of a 21-meter (65-foot) wave that hit a portion of the coastline near the island of Nusa Kambangan, indicating a second event that may have added to the severity of the disaster.

    Elsewhere along the 300 kilometers of coastline studied by the International Tsunami Survey team, the waves ranged from 5 to 7 meters, 16 to 24 feet.

    “This event indicates that there was likely a combination of both a tectonic tsunami and a submarine landslide or a canyon failure triggered by the earthquake,” said Fritz, whose research is supported by the U.S. National Science Foundation. “The runup was unusually high along one portion of the coast, too much for a 7.8 magnitude earthquake. The only explanation we could think of is that a submarine mass movement triggered by the earthquake could have added to the effect of the earthquake, given the essentially straight coastline with little room for large-scale tsunami focusing.”

    For people in seismically-active areas like Indonesia, an earthquake usually provides the first warning of a tsunami. Whether caused by an earthquake or an underwater landslide, the first visible sign of an oncoming tsunami is often a rapid withdrawal of the ocean that exposes the seafloor or coral reefs. When that appears, the first tsunami wave won’t be far behind.

    In the July 2006 Java tsunami, lifeguards did not notice the withdrawal because the water was receding anyway because of a normal low tide – and because of large wind-produced waves.

    “The lifeguards did not recognize the precursors of the tsunami, either the shaking of the earth or the drawing down of the sea,” said Fritz, who also interviewed survivors of the 2004 Indonesian tsunami. “The irony is that many of the lifeguards survived because they were in tall concrete structures sitting more than four meters above the ground, getting just their feet wet – a classic example of vertical evacuation in engineered structures. We interviewed one of them, and it was quite moving. It was his job to watch out for the people on the beach, and what happened was pretty tough on him.”

    Survivors compared the sound of the tsunami to that of an aircraft landing or a loud boiling sound. “That primarily comes from the bore forming, or breaking of the waves a couple of hundred meters off shore,” Fritz explained. “In high impact areas, the first tsunami wave then comes in as a rolling wave of water, whereas in low-impact areas it may only be recognized as an unusually fast and high tide.”

    A tsunami normally produces more than one wave, and the waves can be 10 or 20 minutes apart. Often, the second or third wave is the largest, so many deaths occur when victims return to low-lying areas to look for relatives or assess damage after the first wave hits.

    In Indonesia, the government has instituted education programs to help residents respond to tsunami warning signs by quickly moving to higher ground. In many cases, safety can mean moving a mile inland or 10 meters up a hill.

    “It’s always going to be difficult to provide a warning in Java because the earthquake zone is so near,” explained Fritz, a faculty member at Georgia Tech’s Savannah, Ga. campus. “It’s most critical for people to be able to evacuate themselves.”

    In other locations, such as the Hawaiian Islands, warning systems are useful because tsunamis caused by continental earthquakes take hours to reach the islands, he said.

    In the deep ocean, tsunami waves move at the speed of a jet aircraft. However, when they approach land, the waves slow as their height builds and energy dissipates. By the time they roll onto a beach, the waves may be moving at vehicle highway speed, but that quickly drops as they encounter structures and vegetation.

    “If you start running from the beach when the tsunami strikes, chances are you are not going to make it,” Fritz said. “But if you have a head-start, you have a much better chance – if you know where you’re going.”

    Source: Georgia Institute of Technology


    www.physorg.com/news101399695.html
  • Re: Tsunami research;

    Tue, October 16, 2007 - 12:10 AM
    Giant Wave Experiment Reveals Poorly Understood Behavior Of Tsunamis
    Science Daily — With the goal of saving lives and preventing environmental and structural damage during real tsunamis, Princeton Engineering researchers created experimental mini-tsunamis in Oregon this summer.

    Existing models for predicting the impact of tsunamis focus on the incoming rush of water while largely ignoring the effect of the powerful forces that a tsunami wave can exert on the earth beneath when it draws back into the ocean.

    “This was the first experiment of this kind and it will allow us to develop a realistic model to show us what really happens to the sand during a tsunami,” said Yin Lu “Julie” Young, an assistant professor of civil and environmental engineering at Princeton University’s School of Engineering and Applied Science.

    Young said that knowing how to construct buildings that stay in place during a tsunami would be especially crucial to survival in certain locations, such as the Waikiki Beach in Hawaii.

    “This is absolutely necessary in a place like Waikiki because in the event of a tsunami there is no place to run,” she said. “It is too populated and the near-shore bathymetry [the topography of the ocean bed] is too flat. The building has to stay intact so that people can evacuate vertically.”

    Young and her colleagues created model-scale tsunamis at Oregon State University’s Tsunami Wave Basin, the largest experimental facility dedicated to the study of tsunamis in North America. She is the lead investigator from Princeton on the study of tsunami-induced sediment transport, part of the larger NSF-sponsored Network for Earthquake Engineering Simulation (NEES) program.

    The experimental wave bed consisted of two flumes, each about 7 feet wide with a base of natural Oregon beach sand. It took three weeks of hard work to set up an experimental mini-tsunami, where each wave lasted only a few minutes, according to Young. “It is a difficult and time-consuming experiment to run due to the difficulty with sand, which changes the bathymetry with every wave,” she said.

    The OSU wave generator produced large waves that – like a tsunami -- had only a crest and no trough. The concrete walls of the flumes had built-in windows that allowed Young and fellow researchers to observe and videotape the action underwater. Four cameras perched overhead also recorded the experiments.

    The ultimate goal of Young’s experiments this summer is to establish “performance-based tsunami engineering” – basically guidelines for building structures that will withstand tsunamis.

    Young and her colleagues are particularly interested in the study of enhanced sediment transport and potential “liquefaction” of the soil, which occurs when a tsunami wave recedes and exerts a sudden decrease in downward pressure on the saturated land; this in turn can cause the sand to liquefy and to flow out as a heavy slurry. Liquefaction can lead to the eventual collapse of buildings, highways or bridge abutments. Tsunamis can also cause landslides and the formation of gigantic potholes called “scours,” which can force underground oil pipelines to pop, resulting in environmental damage.

    Most previous tsunami experiments have taken place over smooth, rigid, impervious bases such as glass, steel or concrete and thus have failed to take into account how the wave can profoundly alter the ground beneath it.

    The problem of sediment transport is especially complex because of so many variables in the dynamics of sand and water, according to Young. “Sediment transport during tsunamis hasn’t been studied well at all,” said Young. “We plan to use this research to create a benchmark test that everyone can use to compare their numerical predictions. Ultimately we want to come up with a design procedure that can give a sense of the risk and the reliability of a structure and its foundation.”

    Young’s research this summer was part of a larger NSF-funded project known as NEESR-SG: Development of Performance Based Tsunami Engineering (PBTE). Young is co-principal investigator on that project and her collaborators include Ron Riggs, Ian Robertson, and Kwok Fai Cheung of University of Hawaii at Manoa, and Solomon Yim of Oregon State University.

    Young was assisted in her research this summer by Princeton Engineering graduate students Xiao Heng, Tan Ting, and Sun Waiching. Adedotun Moronkeji, an undergraduate from the University of Missouri-Rolla, also assisted in the research as part of the NSF-funded Research Experience for Undergraduates program. Trevor Clark, a high school student from Oregon, helped with the experiments and processing the video of the experimental waves.

    Note: This story has been adapted from material provided by Princeton University


    www.sciencedaily.com/release...3915.htm
    • Unsu...
       
      Research announced this week by a team of U.S. and Japanese geoscientists may help explain why part of the seafloor near the southwest coast of Japan is particularly good at generating devastating tsunamis, such as the 1944 Tonankai event, which killed at least 1,200 people. The findings will help scientists assess the risk of giant tsunamis in other regions of the world.
      Geoscientists from The University of Texas at Austin and colleagues used a commercial ship to collect three-dimensional seismic data that reveals the structure of Earth's crust below a region of the Pacific seafloor known as the Nankai Trough. The resulting images are akin to ultrasounds of the human body.

      The results, published this week in the journal Science, address a long standing mystery as to why earthquakes below some parts of the seafloor trigger large tsunamis while earthquakes in other regions do not.

      The 3D seismic images allowed the researchers to reconstruct how layers of rock and sediment have cracked and shifted over time. They found two things that contribute to big tsunamis. First, they confirmed the existence of a major fault that runs from a region known to unleash earthquakes about 10 kilometers (6 miles) deep right up to the seafloor. When an earthquake happens, the fault allows it to reach up and move the seafloor up or down, carrying a column of water with it and setting up a series of tsunami waves that spread outward.

      Second, and most surprising, the team discovered that the recent fault activity, probably including the slip that caused the 1944 event, has shifted to landward branches of the fault, becoming shallower and steeper than it was in the past.

      "That leads to more direct displacement of the seafloor and a larger vertical component of seafloor displacement that is more effective in generating tsunamis," said Nathan Bangs, senior research scientist at the Institute for Geophysics at The University of Texas at Austin who was co-principal investigator on the research project and co-author on the Science article.

      The Nankai Trough is in a subduction zone, an area where two tectonic plates are colliding, pushing one plate down below the other. The grinding of one plate over the other in subduction zones leads to some of the world's largest earthquakes.

      In 2002, a team of researchers led by Jin-Oh Park at Japan Marine Science and Technology Center (JAMSTEC) had identified the fault, known as a megathrust or megasplay fault, using less detailed two-dimensional geophysical methods. Based on its location, they suggested a possible link to the 1944 event, but they were unable to determine where faulting has been recently active.

      "What we can now say is that slip has very recently propagated up to or near to the seafloor, and slip along these thrusts most likely caused the large tsunami during the 1944 Tonankai 8.1 magnitude event," said Bangs.

      The images produced in this project will be used by scientists in the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), an international effort designed to, for the first time, "drill, sample and instrument the earthquake-causing, or seismogenic portion of Earth's crust, where violent, large-scale earthquakes have occurred repeatedly throughout history."

      "The ultimate goal is to understand what's happening at different margins," said Bangs. "The 2004 Indonesian tsunami was a big surprise. It's still not clear why that earthquake created such a large tsunami. By understanding places like Nankai, we'll have more information and a better approach to looking at other places to determine whether they have potential. And we'll be less surprised in the future."
      www.terradaily.com/reports
  • Re: Tsunami research;

    Wed, March 19, 2008 - 1:46 AM
    Forecasting Tsunami Threats Through Layers Of Sand And Time

    ScienceDaily (Mar. 18, 2008) — Azhii peralai: from the deep … large waves. This is the expression for ‘tsunami’ in Tamil, the oldest language in southern India.



    For an ancient dialect to have its own phrase for destructive waves triggered by earthquakes, the people of Tamil Nadu likely experienced tsunamis periodically through the centuries, says Halifax scientist Alan Ruffman.

    In other words, the catastrophic Indian Ocean event in December 2004 that killed 230,000 people in a dozen countries – including 15,000 in India – was hardly a one freak occurrence, he says, and people could have been much better prepared for it.

    The proof lies in the layers below the Earth’s surface, says Mr. Ruffman, honorary research associate in Dalhousie’s Department of Earth Sciences. What better way to predict the threat of future tsunamis than studying patterns from the past? Coastal sediments provide a potent geological record of recent and ancient tsunamis, he says, adding that the size of the sand particles can provide clues about the actual height of the water column.

    He points to a compelling photo of a research colleague at a dig in Thailand, showing four distinct bands of sand. The surface layer was deposited by the 2004 tsunami, and Mr. Ruffman figures the next layer was left by an event dating back 400 to 600 years. “The tsunami that laid that one down was probably about the same size as the one in 2004,” he says.

    This kind of research is relatively new. Much more study is required to develop statistics and timelines that can serve as a guide to help people in Southeast Asia better prepare for the next monster wave. And Halifax will be part of that important effort, Mr. Ruffman learned last week. The Shastri Indo-Canadian Institute has awarded a seed grant to help Dalhousie develop a tsunami research partnership with the University of Madras in Chennai, India.

    In his funding proposal, Mr. Ruffman envisioned a long-term alliance to generate potentially life-saving new knowledge from research by faculty and students in the two coastal cities, starting with in-depth study of the history of tsunamis in the Bay of Bengal. This will range from detailed geological sediment studies to analysis of southern India’s early writings and folklore, to find human accounts of early tsunamis.

    “There are more than 1,500 unanalyzed early documents in the Tamil language that stretch back one to two thousand years,” says Mr. Ruffman.

    And if the Tamil Nadu sediments tell a similar story to the layers shown in the striking photo from Thailand, “then our scientific team should be able to put a solid estimate on the return period of such devastating events. This would allow communities and governments to put in place the necessary tsunami warning systems and evacuation procedures for future events,” Mr. Ruffman says.

    It could go much further than that, with such proactive steps as restoring mangrove vegetation, to help prevent tsunami erosion along coastlines, and even moving whole villages to safer locations.

    “If the understanding of the very real and present tsunami hazard leads to better location of coastal villages, housing and infrastructure, then the financial and human losses during future tsunamis will be greatly reduced. But planners and governments will have to believe that the 2004 tsunami was not a unique event ... and there’s nothing like finding a signature of a historic event to convince the local policy-makers it has occurred before.”

    The Shastri funding proposal suggests Dalhousie would host a week-long series of workshops, seminars and social functions, attended by tsunami researchers from Madras, as well as local scholars and members of Halifax’s Indo-Canadian community. The Earth scientists would also use the time to hammer out a plan for their cooperative research program, and explore opportunities for graduate student exchanges between the two universities.

    The core research team would include four Madras scholars, six Dalhousie faculty members in Earth Sciences and Oceanography, and the Bedford Institute of Oceanography.

    Mr. Ruffman has been researching tsunamis for more than two decades. His main focus thus far has involved historic events in the Atlantic, such as the 1755 Lisbon Tsunami, and the 1929 Grand Banks event that killed 28 people in Newfoundland.

    “In 1929 the tsunami surged up to a kilometre and a half inland,” he noted. “Houses were floating out to sea with oil lamps still seen burning in the windows. These events, though rare, do occur in the Atlantic.”

    In a recent presentation to the Atlantic Geoscience Society, he also discussed possible connections between climate change and tsunamis—coastal areas with rapid deglaciation can become vulnerable to shifts in the Earth’s crust, triggering seismic activity that could launch tsunamis.

    “It’s not a hazard that will happen tomorrow, or often,” says Dr. Ruffman. But once tsunami researchers get a handle on the Bay of Bengal, there’s plenty more work to be done in Greenland, Iceland and Labrador, he says.

    Adapted from materials provided by Dalhousie University, via Newswise.
  • Re: Tsunami research;

    Sun, September 21, 2008 - 8:22 AM
    Japan's Tsunami History Shows What's in Store
    Michael Reilly, Discovery News

    Sept. 19, 2008 -- Newly discovered tsunami deposits suggest the Japanese coastline was hammered by a series of massive waves thousands of years ago. The finding adds to growing evidence that the region is regularly pounded by killer waves, and could help in planning for future inundations.

    The northern Japanese island of Hokkaido is nestled up against the Kuril-Kamchatka trench, a place where the Pacific tectonic plate dives beneath the Eurasian plate, and home to terrible earthquakes in excess of magnitude 8.0.

    Now Wesley Nutter and a team of researchers say nine waves, each at least 33 feet high, battered the coastline before the dawn of civilization on the island.

    "In recorded history, tsunamis have hit the Hokkaido coast over and over again," Wesley Nutter of Earlham College in Indiana said. "But something of that size has never been recorded here."

    Nutter and a team of researchers dug down into the sediments of a saltwater marsh on the island looking for signs of past tsunamis. Team member Kazuomi Hirakawa of Hokkaido University had first noticed a series of sand deposits several years ago there that had no business in a marsh mostly made of peat.

    Tracing the sand deposits away from the coast, the team found they extend up to more than a mile inland and get thinner further from the sea.

    In theory, huge storm surges could have deposited the sand, but a tempest with a 13-foot surge raked the region several years ago and left no sign of its passing in the marsh, which is protected by 33-foot-high cliffs.

    Nutter believes the deposits have tsunami origins. And they must have been big: In 2003 a magnitude 8.3 earthquake in the Kuril trench generated a wave 13 feet high, not nearly enough to reach the marsh.

    The deposits also seem to repeat every 500 years or so, suggesting the Kuril is capable of regularly ripping off huge earthquakes that could have devastating results.

    "The new research should help define the inundation hazard that the tsunamis pose," Brian Atwater of the United State Geological Survey said in an e-mail to Discovery News. "The research may also lay groundwork for improved estimates of the size and recurrence intervals of the associated earthquakes."

    In a paper published last year, Atwater pointed out the Japanese government has already recalculated the tsunami hazard based on the team's initial results. In the case of an extraordinary earthquake, the resulting tsunami could destroy 5,600 homes and kill 850 people, even though the country has an advanced tsunami warning system in place.


    dsc.discovery.com/news/2008...unami.html
  • Re: Tsunami research;

    Wed, September 24, 2008 - 2:19 PM
    Discovered: World’s Largest Tsunami Debris

    Newswise — A line of massive boulders on the western shore of Tonga may be evidence of the most powerful volcano-triggered tsunami found to date. Up to 9 meters (30 feet) high and weighing up to 1.6 million kilograms (3.5 million pounds), the seven coral boulders are located 100 to 400 meters (300 to 1,300 feet) from the coast. The house-sized boulders were likely flung ashore by a wave rivaling the 1883 Krakatau tsunami, which is estimated to have towered 35 meters (115 feet) high.

    “These could be the largest boulders displaced by a tsunami, worldwide,” says Matthew Hornbach of the University of Texas Institute for Geophysics. “Krakatau’s tsunami was probably not a one-off event.” Hornbach and his colleagues will discuss these findings on Sunday, 5 October 2008, at the Joint Annual Meeting of the Geological Society of America (GSA), Soil Science Society of America (SSSA), American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Gulf Coast Association of Geological Societies (GCAGS), in Houston, Texas, USA.

    Called erratic boulders, these giant coral rocks did not form at their present location on Tongatapu, Tonga’s main island. Because the island is flat, the boulders could not have rolled downhill from elsewhere. The boulders are made of the same reef material found just offshore, which is quite distinct from the island’s volcanic soil. In fact, satellite photos show a clear break in the reef opposite one of the biggest boulders. And some of the boulders’ coral animals are oriented upside down or sideways instead of toward the sun, as they are on the reef.

    Hornbach says the Tongatapu boulders may have reached dry land within the past few thousand years. Though their corals formed roughly 122,000 years ago, they are capped by a sparse layer of soil. And the thick volcanic soils that cover most of western Tongatapu are quite thin near the boulders. This suggests the area was scoured clean by waves in the recent past. Finally, there is no limestone pedestal at the base of the boulders, which should have formed as rain dissolved the coral if the boulders were much older.

    Many tsunamis, like the one that struck the Indian Ocean in 2004, are caused by earthquakes. But the boulders’ location makes an underwater eruption or submarine slide a more likely culprit. A chain of sunken volcanoes lies just 30 kilometers (20 miles) west of Tongatapu. An explosion or the collapse of the side of a volcano such as that seen at the famous Krakatau eruption in 1883 could trigger a tremendous tsunami.

    Another possibility is that a storm surge could have brought the boulders ashore. But that scenario isn’t likely. No storms on record have moved rocks this big. Another possibility is that a monster undersea landslide caused the tsunami. But Hornbach’s analyses of adjacent seafloor topography point to a volcanic flank collapse as the most probable source of such a wave.

    “We think studying erratic boulders is one way of getting better statistics on mega-tsunamis,” Hornbach says. “There are a lot of places that have similar underwater volcanoes and people haven’t paid much attention to the threat.” The researchers have already received reports of more erratic boulders from islands around the Pacific. Future study could indicate how frequently these monster waves occur and which areas are at risk for future tsunamis.

    The boulders are such an unusual part of the Tongan landscape that tales of their origins appear in local folklore. According to one legend, the god Maui hurled the boulders ashore in an attempt to kill a giant man-eating fowl.

    And though many other Pacific islanders follow the custom of heading uphill after earthquakes, Tongans have no such teachings. Such lore may be useless for near-shore volcanically-generated tsunamis, which arrive too quickly for people to evacuate. Instead, most of Tongatapu’s settlements are huddled together on the northern side of the island—away from the brunt of the tsunami threat.

    **WHEN & WHERE**

    Sunday, 5 October 2008, 8:00 AM-4:45 PM (authors scheduled from 3:00-4:45 PM)
    View abstract, Paper 149-8: “Unraveling the Source of Large Erratic Boulders on Tonga: Implications for Geohazards and Mega-Tsunamis” at
    gsa.confex.com/gsa/2008AM..._149849.htm
    George R. Brown Convention Center: Exhibit Hall E (poster, booth 202)


    **IMAGES AVAILABLE**

    For more information on the 2008 Joint Meeting visit www.acsmeetings.org.

    www.geosociety.org


    www.newswise.com/articles/view/544601/
  • Re: Tsunami research;

    Wed, October 29, 2008 - 1:37 PM
    Tsunami in 2004 'not the first'
    By Jason Palmer
    Science and Technology reporter, BBC News

    The Indian Ocean tsunami in 2004 was not the first of its size to hit the region, according to new research.

    Two international collaborations have sampled the sediments in Thailand and Sumatra to examine tsunami history.

    At both sites, there was evidence of sediment laid down by a large tsunami between 600 and 700 years ago, pre-dating written and oral records.

    The findings, reported in Nature, could be used to put statistical weight behind estimates of future tsunami.

    The surge of a tsunami brings with it a great deal of sediment that rushes inland; the bigger the tsunami, the deeper and further inland the layer of sediment it leaves behind.

    In locations where those deposits aren't disturbed by wind or running water, they can be used as a historical record of these powerful events after more layers are added.

    The study of these layers in coastal regions has revealed instances of tsunami elsewhere in the world, including a prehistoric event that inundated the Shetland and Orkney islands off Scotland.

    To investigate the tsunami record in the Indian Ocean basin, two research groups took core samples that capture the layers of sediment below the surface.

    One group, led by Kruawun Jankaew of Chulalongkorn University in Thailand, sampled 150 sites on Phra Thong, a barrier island off the west coast of Thailand. Another group headed up by Katrin Monecke, now at the University of Pittsburgh, sampled 100 sites in the Aceh region in the north of Sumatra.

    In both locations, a deep sandy layer was found beneath the surface, matching the top layer of sand left from the 2004 tsunami. By using radiocarbon dating to estimate the age of the buried sand layer, both teams found that they came from 600-700 years ago.

    Dr Monecke's team also found evidence of a deeper sandy layer, with a corresponding age of about 1,200 years, suggesting a "recurrence time" for large tsunami of around 600 years.

    Those buried layers occurred as far inland as those on the surface, suggesting that the tsunami that deposited them centuries ago was of roughly the same size as the 2004 event.

    The team in Thailand found some suggestion of the 1,200 year-old layer and more substantial evidence for layers corresponding to around 2,000 years ago.

    Timely results

    Though the earthquakes that drive tsunami don't happen predictably, the results, reported in the journal Nature, suggest that another tsunami of that scale will not occur in the near future.

    Roger Musson of the British Geological Survey says that the findings are "not only interesting but useful because from a point of view of understanding the hazard. It's important to know what the recurrence time is."

    "Geological data is increasingly being used to back up forecasts of how likely there is to be large earthquakes in the future."

    From Dr Monecke's point of view, that kind of information can serve as a basis for tsunami education in the region. That, she says, could contribute to policy decisions in the near term.

    "For coastal planners I think it's very important to know this," Dr Monecke told BBC News.

    "We saw that whole villages were being relocated 10km [6 miles] inland, and these people are mainly fishermen.

    "You have to balance this; would it be better to be that far away so that if in a few generations, another tsunami hits, and they are that far away, or would it be better to stay at the coastline and be prepared for it?"




    news.bbc.co.uk/1/hi/sci/tech/7697482.stm
    • New York NY (SPX) Jan 04, 2009
      A team of scientists from the New York-based Wildlife Conservation Society (WCS) has reported a rapid recovery of coral reefs in areas of Indonesia, following the tsunami that devastated coastal regions throughout the Indian Ocean four years ago today.
      The WCS team, working in conjunction with the Australian Research Council Centre of Excellence for Coral Reef Studies (ARCCoERS) along with government, community and non-government partners, has documented high densities of "baby corals" in areas that were severely impacted by the tsunami.

      The team, which has surveyed the region's coral reefs since the December 26, 2004 tsunami, looked at 60 sites along 800 kilometers (497 miles) of coastline in Aceh, Indonesia. The researchers attribute the recovery to natural colonization by resilient coral species, along with the reduction of destructive fishing practices by local communities.

      "On the 4th anniversary of the tsunami, this is a great story of ecosystem resilience and recovery," said Dr, Stuart Campbell, coordinator of the Wildlife Conservation Society's Indonesia Marine Program. "Our scientific monitoring is showing rapid growth of young corals in areas where the tsunami caused damage, and also the return of new generations of corals in areas previously damaged by destructive fishing. These findings provide new insights into coral recovery processes that can help us manage coral reefs in the face of climate change."

      While initial surveys immediately following the tsunami showed patchy (albeit devastating) damage to coral reefs in the region, surveys in 2005 indicated that many of the dead reefs in the study area had actually succumbed long ago to destructive fishing practices such as the use of dynamite and cyanide to catch fish. It is also possible that the crown of thorns starfish-a marine predator-had caused widespread coral mortality.

      Since then, some communities have moved away from destructive fishing and have even begun transplanting corals to recover damaged areas.

      For example, Dodent Mahyiddin, a dive operator on Weh Island, leads an effort to transplant corals onto hand-laid underwater structures to restore a badly damaged reef in front of the remains of his dive shop, which was also destroyed by the tsunami. Already he is seeing widespread colonization of young corals.

      On a larger scale, the WCS team is working to establish community-based coral reef protected areas based on customary marine laws that were first established in the 1600's and maintained throughout Dutch colonial rule. The laws empower local communities to manage their own local marine resources rather than adhere to nationalized protected areas.

      Healthy coral reefs are economic engines for Acehnese communities, according to WCS, supplying commercially valuable food fish as well as tourism dollars from recreational diving.

      "The recovery, which is in part due to improved management and the direct assistance of local people, gives enormous hope that coral reefs in this remote region can return to their previous condition and provide local communities with the resources they need to prosper," said Dr. Campbell. "The recovery process will be enhanced by management that encourages sustainable uses of these ecosystems and the protection of critical habitats and species to help this process."

      The study area is adjacent to the "Coral Triangle," a massive region containing 75 percent of the world's coral species shared by Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands, and Timor-Leste.

      The region is estimated to generate more than $2 billion per year in revenues and supports more than 120 million people dependent on its resources for food security and employment. The "Coral Triangle Initiative," an effort to save the region's reefs and contribute to sustainable livelihoods, has received global support.

      The U.S. State Department and the U.S. Agency for International Development (USAID) have together pledged over $32 million over a five-year period towards this initiative alongside contributions from other major donors, including the Global Environment Facility and twenty-one other Heads of State totaling over $400 million in pledges. WCS conducts conservation projects in this globally important region, and also works on coral conservation in Belize, Papua New Guinea, Fiji, and Madagascar.

      The U.S. Department of State along with the International Coral Reef Initiative (ICRI) through recent commemorations of 2008 as the International Year of the Reef (IYOR) has engaged other leading nations by continuing to strengthen political will and commitment to conserving the resource-rich reefs of the world.

      www.terradaily.com

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