RAC Meeting 2008
Meeting Materials/Presentations:
- Meeting agenda
- Current PNSN Status - Paul Bodin Presentation
- Strategic Considerations - John Vidale Presentation
- Minutes (PDF Version)
Minutes of ANSS Pacific Northwest Regional Advisory Committee
27 May 2008
minutes prepared by Tom Yelin
The meeting was held at the University of Washington Seattle campus, in the
University of Washington Club facility (formerly the Faculty Club). It began at
approximately 10:10 AM and ended at about 2:10 PM (with a brief break for
lunch).
Please see bottom of page for the list of attendees.
Paul Bodin began with a report on the status of the PNSN, including progress
made in replacement of aging network infrastructure and an increase in the
number of permanent stations, both broad band and strong motion (see for
example the slides labeled “New Stations” and “Advances” in the PDF version of
the Power Point presentation.
After this status report, specific topics were introduced and discussed in varying
length and detail. Because Craig Weaver had to leave by 12:30, John Vidale
rearranged the agenda to begin with the topics about which Craig had
information.
Use of ANSS products
The discussion focused on what was learned from the Sound Shake 2008
earthquake exercise. The ground rules (namely restricting use of the Internet for
the first part of the exercise) compromised use of ShakeMap.
Once it was available it seemed like many persons involved made little or no use
of ShakeMap. The sense of this group is that this lack of use arises at least in
part from lack of familiarity with ShakeMap. One person commented that
handing an EOC staff member a ShakeMap manual and telling them to read it is
not a useful tactic. To be useful to EOC personnel and responders in the field,
ShakeMap has to be easy to use, and these people need adequate training in its
use ( but not too much training, because if it requires too much training, we have
failed in the first requirement).
Several people agreed with the statement that a clearly highlighted link to the
“did you feel it” map from the ShakeMap page for any earthquake would be
helpful for initial evaluation of geographic extent of an earthquake’s effects.
C.B. Crouse speculated that emergency response personnel in Washington and
Oregon might be able to learn more about ShakeMap by being directed toward
California earthquake ShakeMaps and “playing” with them. Eric Holdeman 2
thought that such people might be better motivated to learn about ShakeMap by
studying ShakeMaps for PNW earthquakes. To increase the “stock” of such
earthquakes, he suggested that we might lower the ShakeMap threshold to
magnitude 3.0.
Multiple ShakeMap updates were a source of confusion during the Sound Shake
exercise. In a real earthquake, such updates will happen. This confusion
indicates the need for better communication between seismologists and EOC
personnel and responders about ShakeMap and its use and limitations (see
comments above about “keeping things simple”).
Someone commented that being able to make ground motion information
available to EOC’s for rapid import into their own GIS systems would be a good
thing.
Instrumentation of dams along the central Columbia River in Eastern
Washington
Craig Weaver required or is likely to require that a half-dozen dams along the Columbia have
some level of seismic instrumentation installed on and/or near them. Two
instruments have just been installed on the Wells Dam by the USGS and PNSN.
Presumably the dam operators will purchase the instruments themselves. The
question is how involved should the PNSN be in installing and maintaining these
instruments, and what should the PNSN’s role be in collection and analysis of the
data.
This group did not arrive at definite answers to these questions.
Concerns that were raised include:
C.B. - a detailed characterization of a dam’s response to strong ground motion will
require more that two or three sets of tri-axial accelerometers.
Engineering expertise is needed to decide what instrumentation is appropriate for
each dam.
NetQuakes
Craig Weaver gave a brief description of the “NetQuake” strong motion
seismograph. It is a relatively cheap (approximately ~$3K per unit) instrument
that could be installed at any location that had DSL or cable broadband Internet
service. Paul Bodin said that a NetQuakes seismograph would automatically
send triggered event data to a central data collection center (in this case the
PNSN), ready for inclusion in an earthworm data processing stream. 3
C.B. noted that $3K per unit still seemed pretty expensive. Someone
commented that if funding was available to place a large enough order, the per
unit cost might decrease.
Craig said that the Department of Homeland Security has expressed some
interest in funding a large deployment of these units in the region between
Seattle and the Canada border, as a prelude to the 2010 Winter Olympic Games.
Craig reported that some Southern California seismologists have hailed
NetQuakes as the “next great revolution” in seismology and that such
instruments are the best hope of achieving the necessary urban seismograph
densities to fulfill the goals of the ANSS.
Earthquake Early Warning (EEW)
John Vildale led this discussion. Some countries (notably Japan) have made
significant progress toward the goal of EEW. Steve Malone agreed that most of
the technical and scientific problems have been resolved. What is lacking is
adequate funding to construct a truly adequate warning system including
hardened telemetry and warning broadcast systems. Also, the benefits of EEW
implementation are not proven, but with some experience in other regions will
become more clear.
Social engineering issues include a robust way to get the early warning out and
training the populace how to best respond to such warnings. There are also
questions about the cost-benefit ratio of such warnings. These problems and
questions still have not been answered.
Joan Gomberg noted that at the recent Nation Earthquake Conference, 1/3 of
attendees indicated that they thought EEW was a “good idea”. Someone noted
that this may have been the equivalent of voting for Mom and Apple Pie.
It was noted that the SESAC report took a cautious view regarding EEW and
although it supported further research on this topic, it should not be at the
expense of other ANSS goals (i.e., it should not have top priority).
Structural Monitoring (led by John Vidale)
See the accompanying PDF/Power Point presentation for the bullets for this
topic. John reported that two tri-axial strong motion units will soon be temporarily
installed on the Alaska Way viaduct.
Overall the structural engineering community has not provided much guidance to
the PNSN regarding ways to contribute to the advance of knowledge of seismic
response of buildings, despite several offers to explore ways to monitor
vulnerable structures such as the Tacoma Narrows Bridge and the Viaduct. Until
this happens, the PNSN cannot do much more than it already has done, which
so far is only some remedial Nisqually analysis and simple monitoring
experiments in the UW Tower and on the viaduct.
GPS data in monitoring
See the PDF/Power Point presentation for bullets on this topic. They were read
with a few comments and we then moved on to the next topic.
Aftershock probabilities
Joan Gomberg reported that the major road block to completing an aftershock
probability study for the Pacific Northwest was time and personnel.
This problem is also probably more complicated than in California, because of
the three distinct classes of earthquakes in the PNW: subduction, shallow crustal
and Benioff zone earthquakes.
C.B. suggested studying other subduction zones as possible analogs to the
Cascadia for the aftershock problem.
The committee recommends that the completion of an aftershock probability
study be placed at a higher priority.
ETS (Episodic Tremor and Slip) studies
John Vidale showed seismograms of Cascadia tremor induced by the passage of
waves from the China earthquake. Joan Gomberg expressed optimism that
instrumentation deployed in the last few years and the concentration of research
activity on ETS will lead to a much greater understanding of subduction zone
processes.
State of Oregon support for earthquake hazard studies
Oregon DOGAMI (Department of Geology and Mineral Industries) obtained
~$100K from the state to purchase 3 TA stations, which the PNSN will operate
and maintain. In the past ~2 years, DOGAMI has purchased three strong motion
instruments to be added to the PNSN. Two of those three strong motion sensors
have been installed in Newport and Monmouth, Oregon. The third is slated for
installation somewhere in eastern Oregon, hopefully by the fall of 2008. 5
We noted ongoing operational fiscal support from the State of Oregon for the
PNSN would be beneficial, and bring monitoring in that state more in line with the
arrangements for monitoring in other states.
Closing thoughts and summary of priority actions
The coming year may see significant fiscal constraints on network operations and
new initiatives. The retirements of George Crawford and Ron Teissere and the
current uncertain status of the Washington State Seismic Safety Commission
presents challenges for continued progress on earthquake issues in state
government.
We briefly discussed membership of the Advisory Committee and no major
changes were viewed as necessary.
Action items:
C.B. Crouse, Susan Chang, and Bill Perkins urge that high priority be given to
the replacement of the failed deepest borehole seismometer at the Seattle
School District headquarters in the Duwamish Valley.
The committee also encourages increased priority be given to completion of a
PNW aftershock probability study.
List of Attendees:
C.B. Crouse, Chair URS Corporation
T.J. McDonald City of Seattle Emergency Management
Dave Nelson Washington State Emergency Management Division
Susan Chang City of Seattle
Craig Weaver USGS Seattle
Bob Zimmerman Boeing and CREW
Gary Gordon Boeing
Bill Perkins Shannon and Wilson
Eric Holdeman ICF International
Tim Walsh Washington DNR
Recep (Ray) Cakir Washington DNR
Luke Meyers Pierce County Emergency Management
John Vidale PNSN, ANSS Regional Co-ordinator
Paul Bodin PNSN
Steve Malone PNSN (emeritus)
Bill Steele PNSN
Joan Gomberg USGS Seattle
Tom Yelin USGS Seattle