Pacific Northwest Seismic Network
ANSS Regional Advisory Committee Meeting
Tuesday, 27 May 2008
Location : UW Club Conference Room
Start Time : 10 am
End Time : 2 pm
Contact : Bill Steele, 206-685-5880
Introduction [Steele] (10:00 - 10:10)
New members, Procedural matters.
Report [Vidale, Bodin] (10:10-10:45)
• Status & Progress
- Funding, Personnel, Operational & Products, Outreach & Political, Scientific.
• Challenges & Opportunities
- Flat funding, NSMP, SS08, Tsunami & Volcano, EW8, Misc.
Strategic Discussion [Committee] (10:45-1:45) [Lunch served during discussion.]
Note: See Brief Descriptions Below...
• Structural Monitoring
• Early Warning
• GPS data in monitoring
• Aftershock probabilities
• ETS monitoring
• Oregon contributions
• Dam instrumentation
Action Items [Crouse, Vidale, Bodin] (1:45-2:00)
Specific questions we would like addressed:
Continued operations and ANSS-mandated changes and upgrades takes up most of our effort. We seek from the RAC advice about the value of, and how much should effort we should put into, these development directions:
1. So far this is a Federal initiative that may fund up to 100 inexpensive strong motion instruments for deployment in the Puget Sound Region's I-5 corridor over the next two years, with the intention of asking for many more.
2. Should network design emphasize central cities, wide areal coverage, near-fault sampling, 200sps recording? Considerations include improving Shakemap, ease of installation and maintenance, favorable geometry for early warning system, and how to ensure that the sufficient funding and manpower is provided.
1. instrumentation of bridges with WSDOT.
2. monitoring site-specific motions, cracking, and changes in structural response.
We are developing an example of the use of ShakeCast applied to UW itself, and will explore whether this is a tool of wide utility. ShakeCast pushes out estimates of shaking and probability of damage at pre-specified sites for organization who are willing to compile such lists of vulnerable places and do the simple maintenance required for the software.
GPS data in monitoring
The ability to see very large (~cm) slow or permanent deformations—or to rule out their occurrence—simultaneously with the more high-frequency seismic information will substantially improve hazard definition in the region. Subduction zones have proven prone to aseismic slip episodes that may affect seismic risk. Inclusion of existing GPS stations would increase density of strong motion measurements. To do this optimally would mean having a geodesist at the UW. We have been pushing for this, but feel we have reached the limit of what we can accomplish without annoying people by whining continuously.
Detecting rapidly when a strong earthquake is in progress and provided seconds to hundreds of seconds of “warning” of imminent shaking is truly the state of the art in seismic monitoring, currently working well only in Japan. This is a direction of potential benefit particularly in our region of the ANSS. Moreover, we think it is only going to become more likely as our technological capabilities advance. We would like advice about how to proceed at this early stage of discussion about early warning.
We have only made slow progress on this issue in the past year. Yet to us it seems important to persevere.
ETS monitoring is called for by SESAC.
ETS seems at the moment to be most important to help define the downdip edge of the locked subduction megathrust fault and, hence, the proximity of energetic rupture to densely populated inland urban areas.
While Washington has seemed to become more interested in supporting seismic hazard monitoring, Oregon lags. One likely reason is that we are located in Washington, and familiarity breeds interaction and awareness. What strategies can we follow in developing a more proactive role for Oregon in the support of regional seismic hazard monitoring.
Should PNSN pursue the instrumenation of dams in eastern Washington. A recent example of this is the Wells dam.
Last Modified : 05/15/2008