***SPECIAL EDITION***
March 21, 2001
For more information on these science news and feature
story tips, please contact the public information
officer at the end of each item at (703) 292-8070.
Editor: Bill Noxon
This is the first in a series on NSF-supported research
in earthquake-related areas. The recent earthquake
centered near Seattle was the subject of a hearing
before the House Science Research Subcommittee Mar.
21, where experts relayed some of their findings.
In addition, research and reconnaissance teams are
working to learn more about the Seattle-area quake.
The National Science Foundation (NSF) supports earthquake-related
research through: multi-agency cooperation under the
National Earthquake Hazards Reduction Program; NSF
Science and Technology Center; Earthquake Engineering
Research Centers; and other interdisciplinary research
and educational activities.
Contents of this News Tip:
When the Puget Sound region of Washington state was
jolted from its morning routine on Feb. 28 by a magnitude
6.8 earthquake, the damage was noticeably less severe
than might have been expected from such a quake, say
scientists at the NSF-funded Southern California Earthquake
Center (SCEC) in Los Angeles. This event, named the
Nisqually earthquake, for a river delta near its epicenter,
was actually larger than the devastating 1994 Northridge
earthquake in California, a magnitude 6.7 quake that
became the most costly natural disaster in U.S. history.
Was the Seattle area better prepared for a major earthquake
than Los Angeles? Or was the discrepancy a result
of differences in the earthquakes themselves?
SCEC geologists say it is the latter. They believe
much of the difference between the Nisqually and the
Northridge quakes can be attributed to the Nisqually
earthquake's location--not that of its epicenter,
but that of its depth, or hypocenter. The Northridge
quake had a hypocentral depth of 11 miles, deep for
a California earthquake, but shallow for other regions.
Nisqually's depth was some 33 miles, making its center
farther away from structures than at Northridge, explaining
the differences in the two quakes' effects. [Cheryl
Dybas]
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The vast network of subterranean pipelines and cables
that sustain our daily utility services are among
the most vulnerable infrastructures to earthquakes,
according to experts at the NSF-funded Multidisciplinary
Center for Earthquake Engineering Research at the
University of Buffalo.
In 1994, the Northridge, Calif., earthquake caused
the most extensive damage to a U.S. water supply system
since the famous 1906 San Francisco earthquake. The
Los Angeles water delivery system required repairs
at more than a thousand locations. In the recent Nisqually
earthquake near Seattle, a hypocenter closer to the
surface also would have resulted in extensive damage.
The Buffalo research facility is using advanced technologies
to recommend new construction and soil improvement
techniques, and changes in design, operations and
response procedures that could mitigate future damage.
Researchers say such improvements could greatly benefit
normal operations as well, by increasing efficiency,
safety and reliability and reducing maintenance and
repair costs. Among the center's tools is a digitized
database of utility lines and repair sites in the
Los Angeles area, assembled after the Northridge quake.
The database, the largest on lifeline seismic performance
ever assembled in the United States, provides a template
for forecasting damage to pipes and modeling potential
water supply losses in urban areas. [Amber Jones]
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After sustaining so little damage in its recent magnitude
6.8 earthquake, Seattle ought not to be lulled into
a false sense of security, says scientist Meghan Miller.
A geologist at Central Washington University in Ellensburg,
Washington, Miller, with her colleagues at various
institutions, is receiving NSF support to augment
the Pacific Northwest Geodetic Array (PANGA). PANGA
is a chain of continuous GPS (Global Positioning System)
stations in the Puget Sound region that will allow
scientists to discover more about the after-effects
of the Nisqually quake.
The PANGA instrument network provides scientists with
information on the "slip" of active faults in the
Seattle metropolitan region. Seven new stations will
add to the more widely spaced existing network of
40 stations, which spans the region from northern
California to the Canadian border, and from the West
Coast as far east as Idaho and Nevada. "An essential
element of long-term earthquake hazard mitigation
is establishing and refining hazard maps," explains
Miller, who testified on earthquake hazards before
the House Science Subcommittee on Research.
By better defining areas most susceptible to strong
shaking, Miller says, future land-use planning can
take this risk into account. "Seismic risk mitigation
in this rapidly developing urban and suburban region
will be greatly improved." [Cheryl Dybas]
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Reconnaissance teams based at the University of Washington
responded within hours of the recent Nisqually earthquake
near Seattle. The teams surveyed damage and assessed
how structures could be strengthened to mitigate future
damage and to prevent injury in future seismic events.
The University of Washington is a member of the NSF-supported
Pacific Earthquake Engineering Research (PEER) Center
headquartered at the University of California, Berkeley.
Coordinated by the NSF-supported Earthquake Engineering
Research Institute (EERI) in Oakland, Calif., such
recon teams survey earthquake impacts worldwide as
soon as possible after all major seismic events. The
teams evaluate how buildings, lifelines (utilities,
bridges and other civil infrastructure) and emergency
systems performed and assess the social and economic
effects.
"Earthquakes serve as a virtual laboratory," says EERI
executive director Susan Tubbesing. She says these
events provide an opportunity to test theories and
determine future research directions, including needed
retrofits of buildings and structures and changes
in emergency planning and response.
The teams include structural, civil and geotechnical
engineers, political scientists, earth scientists,
architects and economists. Earthquake researchers
and engineers across the world can access their reports
via the Internet. [Amber Jones]
For the report on the Nisqually earthquake, see: http://eeri.org/Reconn/Nisqually_Wa_2001/NisquallyEQrep.PDF
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The Nisqually earthquake in February eventually led
to the involvement of more than a dozen organizations,
including NSF, to make critical early observations
of the impacts and damage.
Priscilla Nelson of NSF's engineering directorate represented
NSF at a House Science Research Subcommittee hearing
Mar 21. Nelson said that, based on preliminary conclusions
of reconnaissance teams evaluating the Nisqually quake's
impact, unique opportunities exist for future research.
One such opportunity, Nelson said, was the chance to
develop a database on direct and indirect losses that
will permit focused evaluation of the economic impacts
from nonstructural damage and disruptions to business.
This information, assembled separately from the cost
of significant structural impacts from catastrophic
earthquakes such as Northridge, will be very important
in making better predictions of economic losses, she
said.
"The Nisqually earthquake presents an opportunity for
social sciences to study the implications of a non-catastrophic
event for the public - in terms of whether to consider
this a wake-up call for continued investment in retrofit
and mitigation, or whether to make a 'quit claim'
on success," she told the Congressional panel.
Nelson also said that Nisqually will provide information
for performance-based engineering design for levels
other than catastrophic failure and loss of functionality.
She said this experience would also allow for more
explicit definition of risks for decisionmakers, property
owners and the public. [Bill Noxon]
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Scientists today can use the latest in 3D graphics
technology to pinpoint and visualize the precise location
of earthquakes.
An NSF-supported team from multiple institutions is
developing the graphical computer simulations. Within
hours of the 6.8-magnitude Seattle-area Nisqually
quake that occurred Feb 28, the team had posted VRML
(Virtual Reality Modeling Language) model images on
the web. The collaborators include geologists at the
University of Minnesota and the University of Michigan,
working with data visualization specialists at the
University of Illinois at Chicago. The collaborations
are supported through NSF's Network for Earthquake
Engineering Simulation program and the NSF-supported
National Center for Supercomputing Applications at
the University of Illinois at Urbana-Champaign. [Tom
Garritano]
For the VRML images of Nisqually, see: http://www.evl.uic.edu/cavern/TIDE/SeattleQuake2001.
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