HOLD FOR RELEASE: THURSDAY, OCT.
23, 1997, 4 P.M., E.T.
Contact: Blaine P. Friedlander, Jr.
Office: (607) 255-3290
Internet: [email protected]
Compuserve: Bill Steele, 72650,565
http://www.news.cornell.edu
ITHACA, N.Y. -- The sea may soon concede more of its seismic secrets. In
this week's journal Science, university researchers report that a
network of instruments will soon be deployed and placed on the ocean floor,
giving humanity a precious tool to predict and track tsunamis in real time.
Tsunamis -- giant seismic sea waves, sometimes as high as a five-story
building -- can crash against coastal communities, kill thousands of people
instantly and devastate property. They are produced by undersea
earthquakes, or landslides or volcanic eruptions.
"From locations all around the Pacific, we cannot now predict what kind of
tsunamis form, where they are from, and how to accurately gauge their
magnitude," said Philip L.F. Liu, Cornell professor of civil and
environmental engineering. "With a new array of instruments, we can start
to research tsunamis and perhaps we'll be able to save lives."
Liu explained that tsunamis travel at speeds close to 600 miles an hour in
the open ocean and at 100 miles an hour closer to the shore, and they are
still difficult to predict. Thus, last spring, scientists gathered at the
Natural Hazards Mitigation Program workshop, in Santa Monica, Calif.,
sponsored by the National Science Foundation, and formulated objectives to
study tsunamis.
The report from the workshop, "Tsunamigenic sea-floor deformations,"
appears in the journal Science (Oct. 24, 1997). It was prepared by
Liu; Costas Synolakis, of the University of Southern California; George
Carrier, of Harvard University; and Harry Yeh, of the University of
Washington.
One initiative of the workshop, now being reported, is that bottom-pressure
recorders (BPR's) and seismic instrument arrays for real-time monitoring of
tsunamic development will be deployed by next year. The instruments will
be placed by the National Oceanic and Atmospheric Administration (NOAA) in
strategic parts of the Pacific rim, such as south of the Aleutian Islands
chain and along coastal areas of Asia.
Another initiative from the workshop was to study sea-floor deformation
characteristics, obtained from seismic data, during undersea earthquakes
that turn into tsunamis.
Liu explained that these natural, hydrologic terrors have devastated many
parts of the world. The 1960 tsunami, resulting from an undersea
earthquake near Chile, killed 5,000 people, and the tsunami traveled at
airplane-like speed through the water to the Hawaiian island chain, where
it killed 61 people and caused millions of dollars in property damage.
After striking Hawaii, the tsunami continued nine more hours, finally
striking Japan and killing 150 people.
The tsunamis do not occur after every oceanic earthquake, said Liu. For
example, if the sea floor shakes from side-to-side, then the effect on
tsunami will be minimal. But, if there is an up-and-down motion, a tsunami
develops. Liu said seismologists now detect several minor tsunamis
annually.
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