Military

10 February 2005

U.S. Pledges More Funding to Tsunami Relief, Warning System

Plans for early warning system include global seismic stations

By Cheryl Pellerin
Washington File Staff Writer

(This is part three of a four-part series on the elements of a tsunami early warning system.)

Washington – The Bush administration is working to boost the U.S. financial pledge to help Indian Ocean nations recover from the December 26, 2004, earthquake and tsunami, officials announced February 9.  President Bush plans to seek congressional support for $950 million in assistance, up from the $350 million commitment the nation made in January.

Officials announcing the increased commitment said $35 million of that amount will help the nations of the region implement an early warning system that might help prevent the tremendous loss of life that has so devastated the region in the aftermath of the December 2004 event.

The announcement comes as international plans for the system are taking shape, with the goal of putting such a warning scheme in place in the region by mid-2006.

A January 28-29 ministerial meeting in Phuket, Thailand, resulted in the Declaration on Regional Cooperation on Tsunami Early Warning Arrangements. That declaration calls for regional and international cooperation in development of the system. The International Oceanographic Commission (IOC) of the U.N. Educational, Scientific and Cultural Organization (UNESCO) and the 59-nation, U.S.-led Global Earth Observation System of Systems (GEOSS) are two wide-ranging efforts to develop such systems.

SEISMIC MONITORING

A critical element of GEOSS and any early warning system for tsunami and other disasters involves seismology -- the study of earthquakes and seismic waves that move through and around the earth.

Seismic waves are waves of energy caused by the sudden motion of rock in the Earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.

There are several kinds of seismic waves that all move in different ways. The two main wave types are body waves and surface waves. Body waves travel through the Earth's inner layers; surface waves move along the planet’s surface like ripples on water. Earthquakes radiate seismic energy as body and surface waves.

The U.S. Global Seismographic Network (GSN) operates 137 stations to monitor the pulse of the planet, distributed uniformly from the South Pole to the Amazon Basin. GSN is operated by the Incorporated Research Institutions for Seismology (IRIS) in the United States and funded jointly by the National Science Foundation (NSF) and the U.S. Geological Survey (USGS).

According to GSN program manager Rhett Butler, the GSN “was designed to record all of the Earth’s signals, from the smallest earthquakes to the greatest earthquakes on scale and all the time, continuously. The network has many purposes -- not only for tsunami warning but for research or any other purpose.”

Each GSN station is in principle a seismometer, which measures the Earth’s vibrations.

“It measures vibration and that is recorded by a computer that turns the signal, which is a voltage, into digital bits and bites,” Butler said. “Then it talks standard Internet protocols -- TCP/IP [transmission control protocol/Internet protocol] over ethernets [computer network hardware] or satellite links or Internet -- and sends data to data centers, to people who request the data or to the tsunami warning center.

“Or,” he added, “you can get on the computer and get it yourself -- http://www.iris.edu/ --and follow the ‘data’ links to real-time data feeds.”

All GSN data are freely and openly available to anyone at any time, he said. The network is extensively used as a primary source of data for tsunami warning by the United States and many other countries.

Stations are installed in a variety of places. Some seismometers are placed in holes drilled 100-150 meters into the Earth. Some are in vaults, which can be rooms, caves or mines. Only one GSN seismic station is on the seafloor – at the bottom of the ocean between Hawaii and California, connected to land by an undersea telephone cable.

“Down at the South Pole we have seismometers that are drilled into the ice because the ice is a couple of kilometers thick there,” Butler said. “In different parts of the world, you have to deal with what’s there. Sometimes you’re on bedrock, which is preferable, but whether you’re on ice or coral, you have to record the vibrations that you can.

“I like to think of it as a vigilant sentinel that’s always there,” he said.

About 85 percent of the 137 GSN stations operate in real time, which means they collect and transmit data automatically. Other stations collect data but must be contacted (dialed up) via modem or other means to allow download of data.

GNS operating costs are about $6 million a year – $3.5 million from USGS and $2.5 million from NSF.

On January 14, the Bush administration earmarked $37 million for a plan to expand U.S. tsunami detection and warning capabilities as part of GEOSS.

Some of that money will go to improve GSN seismic sensor data and infrastructure for better earthquake detection and warning, including putting more stations online.

According to an article in the February 8 issue of Eos, Transactions of the American Geophysical Union, the December 26, 2004, South Asian subduction zone rupture was the first full-scale test of GSN technical design goals, which scientists set more than 20 years ago.

Seismic waves from the 9.0-magnitude Sumatra earthquake reached a monitoring station in Sri Lanka within four minutes and caused needles on thousands of seismometers worldwide to jump within 21 minutes.

Author Jeffrey Park of Yale University and his colleagues noted that, with the network now online and the planned addition of more seismograph locations to the system, strong seismic events in the future can be continuously monitored in unprecedented detail from the instant the first signals arrive at monitoring stations.

Such direct observations could allow scientists to quickly determine the magnitude of an event and its precise location in near real time, the authors wrote.

Looking ahead, GSN’s Butler said, “the real goal at this point to improve global coverage is to work with the oceanographic community to get stations on the seafloor . . . . Ideally,” he said, “we would like to have the kind of coverage on the ocean floor that we have on land -- so maybe double the size of our network.

“That will take quite a while because it’s difficult to do things in the ocean. If we had 100 stations on the sea floor I think people would say we had pretty good coverage,” Butler added.

Part four of this series on the elements of a tsunami early warning system will examine international cooperation in seismic monitoring and the International Monitoring System of the Comprehensive Nuclear Test Ban Treat Organization.

For additional information, see Part 1 and Part 2 of this series.

Information about the Global Seismographic Network is available at http://www.iris.edu/about/GSN/

(The Washington File is a product of the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)