(Press-News.org) Geologists studying the Jan. 12 Haiti earthquake say the risk of destructive tsunamis is higher than expected in places such as Kingston, Istanbul, and Los Angeles.
Like Haiti's capital, these cities all lie near the coast and near an active geologic feature called a strike-slip fault where two tectonic plates slide past each other like two hands rubbing against each other.
Until now, geologists did not consider the tsunami risk to be very high in these places because when these faults rupture, they usually do not vertically displace the seafloor much, which is how most tsunamis are generated. This latest research suggests even a moderate earthquake on a strike-slip fault can generate tsunamis through submarine landslides, raising the overall tsunami risk in these places.
"The scary part about that is you do not need a large earthquake to trigger a large tsunami," said Matt Hornbach, research associate at The University of Texas at Austin's Institute for Geophysics and lead author on a paper describing the research in the Oct. 10 online edition of the journal Nature Geoscience.
"Organizations that issue tsunami warnings usually look for large earthquakes on thrust faults," said Hornbach. "Now we see you don't necessarily need those things. A moderate earthquake on a strike-slip fault can still be cause for alarm."
Within minutes after the magnitude 7 Haiti earthquake, a series of tsunami waves, some as high as 9 feet (3 meters), crashed into parts of the shoreline. A few weeks later, a team of scientists from the U.S. and Haiti conducted geological field surveys of sites on and offshore near the quake's epicenter.
The scientists determined the tsunamis were generated primarily by weak sediment at the shore that collapsed and slid along the seafloor, displacing the overlying water. Combined with newly discovered evidence of historic tsunamis, the survey revealed a third of all tsunamis in the area are generated in this way. Geologists had previously estimated only about 3 percent of tsunamis globally are generated through submarine landslides.
"We found that tsunamis around Haiti are about 10 times more likely to be generated in this way than we would have expected," said Hornbach.
In addition to Hornbach, team members from The University of Texas at Austin include: Paul Mann, Fred Taylor, Cliff Frohlich, Sean Gulick and Marcy Davis. The team also includes researchers from Queens College, City University of New York; U.S. Geological Survey, University of Missouri; Lamont-Doherty Earth Observatory of Columbia University; University of California, Santa Barbara; Bureau of Mines and Energy (Haiti); and Universite d'Etat de Haiti.
The researchers gathered data on faults beneath the seafloor and land, vertical movement of the land, bathymetry (underwater topography) of the seafloor and evidence of tsunami waves. They worked on foot, on a small inflatable boat and on the 165-foot research vessel Endeavor.
This research was funded by a Rapid Response grant from the National Science Foundation and The University of Texas at Austin's Jackson School of Geosciences.
With additional funding from The Society for Geophysics' Geoscientists Without Borders program, Hornbach and others are now conducting a new research project in nearby Jamaica to assess the tsunami threat there.
"The geology of Kingston, Jamaica is nearly identical to Port Au Prince, Haiti," said Hornbach. "It's primed and ready to go and they need to prepare for it. The good news is, they have a leg up because they're aware of the problem."
###
For a link to images, contact Marc Airhart (mairhart AT jsg.utexas.edu).
END
NEW BRUNSWICK, N.J. – Physicists at Rutgers University have discovered new properties in a material that could result in efficient and inexpensive plastic solar cells for pollution-free electricity production.
The discovery, posted online and slated for publication in an upcoming issue of the journal Nature Materials, reveals that energy-carrying particles generated by packets of light can travel on the order of a thousand times farther in organic (carbon-based) semiconductors than scientists previously observed. This boosts scientists' hopes that solar cells based on ...
CORVALLIS, Ore. – The soils in large areas of the Southern Hemisphere, including major portions of Australia, Africa and South America, have been drying up in the past decade, a group of researchers conclude in the first major study to ever examine "evapotranspiration" on a global basis.
Most climate models have suggested that evapotranspiration, which is the movement of water from the land to the atmosphere, would increase with global warming. The new research, published online this week in the journal Nature, found that's exactly what was happening from 1982 to the ...
Researchers at the Georgia Institute of Technology and Emory University have developed a novel approach for delivering small bits of genetic material into the body to improve the treatment of inflammatory bowel diseases. Delivering short strands of RNA into cells has become a popular research area because of its potential therapeutic applications, but how to deliver them into targeted cells in a living organism has been an obstacle.
In the Oct. 10 advance online edition of the journal Nature Materials, researchers describe how they encapsulated short pieces of RNA into ...
Children who spend longer than two hours in front of a computer or television screen are more likely to suffer psychological difficulties, regardless of how physically active they are.
The PEACH project, a study of over a 1,000 children aged between ten and 11, measured the time children spent in front of a screen as well as their psychological well being. In addition, an activity monitor recorded both children's sedentary time and moderate physical activity. The results showed that more than two hours per day of both television viewing and recreational computer use ...
Racial disparities in the receipt of breast cancer care persist despite accounting for patients' insurance and social and economic status. That is the conclusion of a study published early online in Cancer, a peer-reviewed journal of the American Cancer Society. The findings suggest that greater efforts are needed to better understand disparities in breast cancer care and to ensure that all affected women receive equal and effective treatments.
Studies have demonstrated that black and Hispanic women are less likely to receive recommended breast cancer treatments than ...
Unless the IT industry adopts new energy-efficient technologies in the coming decade, it runs a serious risk of being unable to contribute to growing the global economy if limits are placed on carbon emissions. The findings come from an 18-month investigation by scholars at the Institute for Sustainable and Applied Infodynamics (ISAID) in Singapore and Rice University's Baker Institute for Public Policy in Houston.
"In the face of growing global concerns over greenhouse carbon emission, the key for the industry is finding new technologies that deliver more performance ...
For most American students, spending a semester or two studying in a foreign country means the opportunity to improve foreign language skills and become immersed in a different culture. For others, studying abroad is more like a prolonged spring break: it can be months with fewer academic responsibilities, plentiful bars and alcohol, and parents far away.
New results from University of Washington researchers point to why some students drink more alcohol while abroad and suggest ways to intervene.
"We hear stories in the media and elsewhere about students going abroad, ...
DALLAS – Oct. 11, 2010 – A clinical trial at UT Southwestern Medical Center aims to determine whether adding the hormone leptin to standard insulin therapy might help rein in the tumultuous blood-sugar levels of people with type 1 (insulin-dependent) diabetes.
This is the first type 1 diabetes treatment trial involving leptin, which is naturally produced by fat cells and involved in body-weight regulation. For this study, UT Southwestern researchers will be using metreleptin, a slightly modified form of the hormone that has been well-tolerated in other clinical trials.
"Leptin ...
Monarch butterflies appear to use medicinal plants to treat their offspring for disease, research by biologists at Emory University shows. Their findings were published online Oct. 6 in the journal Ecology Letters.
"We have shown that some species of milkweed, the larva's food plants, can reduce parasite infection in the monarchs," says Jaap de Roode, the evolutionary biologist who led the study. "And we have also found that infected female butterflies prefer to lay their eggs on plants that will make their offspring less sick, suggesting that monarchs have evolved the ...
The Colorado Cleantech Industry Association(CCIA) has released names of the finalists for its inaugural "Colorado Cleantech Awards Celebration" recognition event, honoring leadership in advancing cleantech. "Winners will be announced at our now officially sold-out event on Tuesday, October 19, 11 a.m. to 1 p.m., at the Denver Marriott City Center," Christine Shapard, CCIA Executive Director announces, "We're extremely pleased to share the twenty finalists who emerged from our statewide call for nominations."
CCIA - Leadership in Advancing Cleantech Awards - Finalists:
* ...