Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mapping the wake of a pending quake

05.12.2006
The seismically active Indonesian island of Sumatra has been hit repeatedly by tsunamis in the past -- and may now be due for another

Research into ancient earthquakes by scientists at USC and Caltech shows that within the next few decades another tsunami from another giant earthquake is likely to flood densely populated sections of western coastal Sumatra, south of those that devastated by the tsunami of Dec. 26, 2004.

The four researchers have modeled the process by which past quakes have flooded cities on that coast, hoping that a more detailed understanding of the future waves will speed preparations that could save lives. Their work will appear in the Proceedings of the National Academy of Sciences (PNAS) on December 4.

"The message of the 2004 tsunami has not been lost, at least in academia," said study participant Costas Synolakis, the director of the USC Viterbi School of Engineering Tsunami Reseach Center. "We are trying to be proactive and help prevent a similar disaster."

Fellow participant Kerry Sieh of Caltech explained, "When we tell people living along this 700-km section of the Sumatran coast that they will likely experience a big tsunami within the next 30 years, they ask for details. How much time after the earthquake will they have before the tsunami strikes" How big will the waves be" How far inland should they be prepared to run" What areas are likely to suffer tsunami damage" We can't answer these important questions without doing the work that we did for this paper."

The same big fault, or megathrust, that caused the tsunami of 2004 extends much farther southeastward, beneath the Indian ocean, just off the southwest coast of Sumatra. Rupture of this section of the megathrust, under the Mentawai islands, produced two great quakes and tsunamis in 1797 and 1833. Such events appear to recur on average every 230 years.

Samples of coral from the islands show how much these previous quakes lifted the sea floor. The patterns of uplift gave the scientists the information they needed to do computer simulations of the historical tsunamis. Synolakis says that the impact of the computed tsunamis is consistent with historical accounts.

The researchers say that this consistency gives them more confidence when they use the same model to evaluate worst-case scenarios from plausible future quakes. USC's Jose Borrero, the senior author of the study, says the results "confirm a substantial exposure of coastal Sumatran communities to tsunami surges." In particular, the coastal city of Bengkalu, with a population of 350,000, showed flooding in its river floodplain that extended up to several kilometers inland.

In the model, offshore islands appear to somewhat shield the larger city of Padang, but even then, the 1797 tsunami was reported to have carried a 200-ton English vessel into the town approximately a kilometer upstream, with smaller vessels carried yet further.

"The population of Padang in 1797 and 1833 was a few thousand," Sieh says. "Now it is about 800,000, and most of it is within a few meters of sea level. We hope that these initial results will help focus educational efforts, emergency preparedness activities, and changes in the basic infrastructure of cities and towns along the Sumatran coast."

Eric Mankin | EurekAlert!
Further information:
http://www.usc.edu

More articles from Earth Sciences:

nachricht Stagnation in the South Pacific Explains Natural CO2 Fluctuations
23.02.2018 | Carl von Ossietzky-Universität Oldenburg

nachricht First evidence of surprising ocean warming around Galápagos corals
22.02.2018 | University of Arizona

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

A Keen Sense for Molecules

23.02.2018 | Physics and Astronomy

“Laser Technology Live” at the AKL’18 International Laser Technology Congress in Aachen

23.02.2018 | Trade Fair News

Newly designed molecule binds nitrogen

23.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>