Energy & Environment

Documents & Texts from America.gov

17 August 2007
Tsunami, Earthquake Detection Improved Since 2004 Disaster

By Cheryl Pellerin
USINFO Staff Writer

This buoy is part of the tsunami warning system in the Pacific, which serves 26 member states in the region and has been hailed as one of the world’s most successful international scientific programs in terms of saving lives and property. Experts around the world are working to develop similar early warning systems in the Indian Ocean, the Caribbean and the Mediterranean. (SHOA photo)

This is the first in a series of articles about U.S. contributions to a global early warning system for tsunamis and other hazards.

Washington -- Peru is two continents and an ocean away from the Indian Ocean, but the speed and accuracy with which a massive earthquake near Lima recently was measured is a direct result of the global response to the 9.1-magnitude temblor and tsunami that struck South and Southeastern Asia on December 26, 2004.

The deadliest disaster in modern history caused the loss of nearly 230,000 people. At the time, the United States and Japan were the only nations whose shores were protected by tsunami early warning systems, and people around the world looked to experts in those countries for help.

Today, in an effort coordinated by the UNESCO Intergovernmental Oceanographic Commission (IOC), a global tsunami warning and mitigation system slowly is taking shape in the world's oceans and along its coastlines. (See related article.)

EARTHQUAKE IN PERU

One hundred to 200 kilometers off the Peruvian coast, tectonic plates that cover the planet are active. There, the Nazca Plate grinds under and pushes up the South American Plate, releasing energy that sometimes becomes an earthquake.

In the early evening on August 15, an 8.0-magnitude earthquake occurred near the coast of central Peru, about 145 kilometers southeast of Lima, according to the U.S. Geological Survey (USGS). The earthquake killed more than 500 people, injuring 1,600 and left tens of thousands homeless.

The National Oceanic and Atmospheric Administration's (NOAA) Pacific Tsunami Warning Center in Hawaii issued and later cancelled a tsunami warning and watch for the Pacific coast of South and Central America, which experienced small tsunami waves less than a meter high.

Among the seismic stations that helped pinpoint and characterize the major earthquake were five new stations that USGS has installed in the Caribbean over the past two years. The agency plans to install four more seismic stations there by the end of 2007.

"These newer instruments are making available the kind of data that makes a difference when trying to estimate the kind of earthquake and the magnitude," seismologist Walter Mooney, lead coordinator for the USGS Indian Ocean tsunami warning system program, said during an August 16 USINFO interview.

"The correct magnitude probably came significantly faster and more accurately than it would have in 2004," he added.

Another difference since 2004 is the expanded use of deep ocean assessment and reporting of tsunami (DART) buoys, designed by NOAA’s Pacific Marine Environmental Laboratory (PMEL) in Seattle to detect tsunamis as they move across the ocean.

The Peruvian tsunami was detected by a Chilean-owned DART buoy that sent tsunami data to the Pacific Tsunami Warning Center within one hour of tsunami generation. The data were used to provide experimental tsunami forecasts for 13 U.S. ports within two hours of tsunami generation.

“The DART data and forecast were instrumental in the quick cancellation of the warning,” said PMEL Director Eddie Bernard, in an August 17 e-mail. “This is the big difference from 2004 to now. With DART data, tsunami forecasts are now possible. Good forecasts lead to good decisions.”

TOWARD GLOBAL EARLY WARNING

In Paris in 2005, the IOC, already tasked with helping U.N. member states on the Indian Ocean rim establish a tsunami warning system, created a framework for developing regional early warning systems in the Indian Ocean, the Caribbean and the Mediterranean.

Along with the Pacific Tsunami Warning System that IOC established in 1965, these regional systems would conform to the same standards, ultimately to share data and form a global system for monitoring and detecting a range of natural and other hazards, including tsunamis. (See related article.)

With funding approved by Congress in 2005, the U.S. Agency for International Development Office of Foreign Disaster Assistance (OFDA), NOAA, USGS, the U.S. Forest Service and the U.S. Trade and Development Agency are lending expertise and technology to these efforts.

For the Tsunami Early Warning and Mitigation System in the North Eastern Atlantic, the Mediterranean and Connected Seas, the United States is acting mainly as an observer and technical provider to the lead group, the Instituto Nazionale di Geofisica e Vulcanologia, one of Europe's largest geophysical research institutions.

"We're working very closely with them," NOAA Tsunami Program Manager David Green, said in an August 15 USINFO interview, "to develop strategies and work with the different observing systems."

LAND USE AND HAZARDS

Progress has been made in the Mediterranean region to bolster and integrate different national seismic and ocean observing networks, and in transitioning from using the instruments for research to using them as part of an operational early warning system.

For the sea-level stations, Green said, "the first steps are to identify the stations that need to be part of the network, then upgrade them to real time [sea-level reporting], then combine them with the seismic effort to make a system."

Until a full-fledged system is in place for the Mediterranean, Italy will provide 24-hour-a-day watch coverage of seismic data from the seas around Europe. Portugal and Spain are providing access to real-time seismic data.

In the meantime, contemplating Europe's heavily developed and populated coastlines, the Mediterranean group brought to IOC's attention the need to bring hazards and coastal zone practices for mitigation and land adaptation and use into every aspect of coastal life. (See related article.)

As a result, IOC brought together experts from its member states, including the United States, and from the World Meteorological Organization and the U.N. International Strategy for Disaster Reduction. The group will develop a set of guidelines for including ocean hazards in integrated coastal zone management.

The concept of integrated coastal area management has been in place since the 1990s for sustainable management of coastal zones but until now has not been applied to tsunami planning.

More information about the Tsunami Early Warning and Mitigation System in the North Eastern Atlantic, the Mediterranean and Connected Seas is available at the IOC Web site.

An animation of the Peru event is available at NOAA Pacific Marine Environmental Laboratory Web site.

(USINFO is produced by the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)

back to top ^