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Lessons from Sumatra
David Applegate

In the months following the devastating earthquake and tsunami that struck the Indian Ocean region on Dec. 26, 2004, U.S. Geological Survey (USGS) scientists and their colleagues around the world have been working hard to learn from the tragedy so that such loss of life does not happen again. Stopping these forces of nature is not part of the plan — we know that extreme events like the giant earthquake off the coast of Sumatra are part of how the earth system goes about its business. But we can make every effort to keep natural hazards from becoming human disasters.

The first lesson from Sumatra is the need for tsunami warning systems wherever coastlines are vulnerable to tsunamis. Such a system was established by the National Oceanic and Atmospheric Administration (NOAA) for parts of the Pacific Ocean following deadly tsunamis that struck Alaska, Hawaii and the U.S. West Coast in the 1950s and 1960s. In January, President Bush proposed expanding that warning system, which includes tide gauges and deep-ocean tsunami-detection buoys, to cover the Pacific and Atlantic oceans and the Caribbean Sea. A number of nations have offered to provide tsunami warning systems in the Indian Ocean region, and the United States is encouraging the use of the Global Earth Observation System of Systems framework to address the need for coordination and interoperability across systems.

Because tsunami warnings begin with rapid earthquake reporting, the president has proposed to increase the number of telemetered U.S. Global Seismographic Network (GSN) stations that can report their data in real time. Today, only 80 percent of GSN, which is funded jointly by the National Science Foundation and USGS and managed by the IRIS Consortium of universities, has that capability and thus can be used for rapid earthquake location. The real-time data is fed directly to the USGS National Earthquake Information Center (NEIC), and from there over dedicated lines to NOAA’s Pacific and West Coast-Alaska Tsunami Warning Centers.

The proposed initiative will upgrade hardware and software systems at NEIC — some of them 20 years old — and implement 24/7 operations there and at the tsunami warning centers to improve the timeliness of global earthquake alerts and tsunami warnings. The president has also proposed installing new GSN stations in the Caribbean, where the subduction zone has generated a magnitude-8 tsunami-causing earthquake as recently as 1946.

Seismic stations, deep-ocean tsunami-detection buoys and tide gauges are one part of a tsunami warning system, but a second lesson from Sumatra is that information has to be effectively disseminated to the people in harm’s way. It is a formidable challenge to sustain the necessary communications networks for a single hazard, particularly one that strikes with relative infrequency.

Fortunately, we already have the example to follow of emergency managers in Washington State, who developed the All-Hazard Alert Broadcasting system (or AHAB) to provide tsunami warnings on beaches. These pole-mounted sirens, lights and speakers are connected to the state’s emergency alert system and can be used for multiple threats. A planned deployment in Seattle later this year will warn not only of tsunamis but also of human-caused emergencies such as hazardous materials accidents and possible terrorist threats.

The third lesson from Sumatra is that the value of warnings depends on a public that knows what to do with them. A big part of the challenge is public education, but before officials can tell people where to go, they need to know what ground is high enough and which escape routes will be accessible. Disseminating such knowledge means having accurate inundation maps, which in turn require bathymetric and topographic data along with geologic studies to constrain the maximum likely impact.

In the United States, the president’s proposal would accelerate NOAA’s inundation mapping and modeling efforts as well as its “TsunamiReady” community preparedness program. In the Indian Ocean region, USGS scientists are participating in international teams to document the inundation heights and collect other information crucial for future modeling. In February, USGS geologist Brian Atwater brought scientists from the affected countries to his field sites in Chile to learn how to reconstruct the history of past tsunamis.

The fourth lesson from Sumatra is that infrequent events do happen with devastating consequences. Much of the reason for the lack of a tsunami warning system in the Indian Ocean is simply that such events are infrequent. The last major basin-wide tsunami was in 1833 following a great earthquake further south along the Sumatra coast, a zone that is now being studied for the potential stress-triggering effects from the Dec. 26 event as well as the subsequent March 28 magnitude-8.7 quake. Even longer ago, the Bay of Bengal suffered such a large tsunami. Natural disasters create teachable moments, in this case raising awareness of the possibility of disaster, no matter how infrequent.

Television certainly played a role in bringing this event home from the other side of the world, and it also brought home the risks faced in the United States. Those of us involved in responding to media questions saw a rapid shift from wanting to know what happened over there to asking whether it could happen here. A month after the event, I was in St. Louis speaking at a business forum during Missouri Earthquake Awareness Week. The place was packed. They weren’t worried about a tsunami on the Mississippi, but the powerful 1811 to 1812 New Madrid earthquakes suddenly seemed far less remote after witnessing the devastation of an even less frequent visitor to the Indian Ocean.

The challenge now is to turn awareness into action. Recognizing that there is much that can be done, USGS is planning a major initiative to deliver the tools that the public, emergency managers, and public and private-sector decision-makers all need to reduce the impacts of catastrophic natural hazards. In addition to tsunamis and earthquakes, the initiative will focus on floods, volcanoes, landslides, wildfires and hurricane impacts.

The challenge is big, but anyone who has heard the accounts or seen the footage from Sumatra, from Thailand, from Sri Lanka and from India knows that it is a challenge well worth pursuing.


Applegate is the senior science advisor for earthquake and geologic hazards at the U.S. Geological Survey. E-mail: applegate@usgs.gov.

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