2018 PNSN, PNW ANSS Advisory Committee Meeting
2018 ANSS-PNW Advisory Committee Meeting
June 13th, 2018
Husky Union Building, Room 334, University of Washington, Seattle
The following notes were taken by Ian Stone (PNSN)
Meeting started at ~9:10 AM
Bill Steele welcomes everyone and introduces CB Crouse, Committee Chairman.
Managers Corner
Paul Bodin:
This meeting is about many-way communication. We are a community who all have a stake in mitigating seismic hazard, and the network is appreciative of the community’s input.
What is PNSN? We use seismic data and observations to reduce seismic risk in the region. We accomplish that in a variety of ways. Our core consists of the UW, UO, and USGS, and we associate with the State of Washington, the DOE, the USGS VHP, the Moore Foundation, ShakeAlert, and ANSS. The RAC helps us guide our activities in the coming year.
Reviewing the 2017 action items:
1) Be thoughtful and careful connecting with users and funders with proceeding with EEW.
-We feel we were thoughtful and careful connecting with users and funders in proceeding with EEW
2) Plan B for funding in the event of bad federal funding outcomes (work with regional partners, local government and private).
-Funding environment was ok, so we did not have to implement a plan B for funding
3) Work with ShakeOut to incorporate ShakeAlert EEW in exercise
4) Regional EEW website revision as part of a long time sustainable plan
5) Basin and other long period shaking impacts within the urban basins
-We are working hard on long-period shaking impacts in urban basins
6) Increase data contributions form external strong motion data contributors.
-We increased data contributions from external strong motion data contributors
7) Support of URM initiative (~70 schools are in URMs).
-We are supporting the city URM initiative.
8) Structural instrumentation. Instrument URM structure for demonstration.
-We did not instrument a URM. Combination of uncertainty in cost and experimental design.
9) Follow up on post-earthquake communication plan with EMD, DNR, etc.
-We did not work on post-earthquake communications. Should continue to be a critical action item.
Update on the Year in PNW Seismicity:
There have not been a lot of M3+ quakes in WA and OR proper (about 13), though we have been busy locating larger earthquakes in our reporting area, and ~3000 elsewhere in the region. Not many more earthquakes this year from last year.
-There was increased activity at Mt. St. Helens (both a swarm in the crater, as well as an event/aftershock sequence nearby), though this has largely simmered down.
-there were 2 small tremor events at opposite ends of the subduction zone in the last few months.
NEHRP:
NEHRP is in the process of reauthorization. The legislation is currently in Congress. It will likely be passed with a unanimous consent vehicle, possibly as soon as July 4th. The House is likely to introduce a bill as well.
Questions:
-CB Crouse: what is the cutoff between an earthquake and tremor?
-Answer: tremor is a period of correlated background noise, comprised of very small magnitude earthquakes.
-Renate Hartog: How does the RAC recommendation make it to ANSS?
-Answer: in our annual report, we include a discussion of what was discussed here. ANSS luminaries are included in the meeting (CB Crouse). There is no formal means of incorporating RAC recommendations, however.
Introduction from Harold Tobin
Paul Bodin: Harold uses seismology, petrophysics and geology to study subduction zones and characterize their hazard. He has led many large projects in the past and is joining us via Zoom from the IRIS meeting in Albuquerque.
Harold’s Address:
Harold Tobin (over Zoom): He is starting September 1st and is excited to learn the job and join the community. Background: he grew up on the east coast and remembers keeping up with news of the Mt. St. Helens eruption as a child. This experience bred an interest that motivated him to volunteer for field work in the PNW during university. PhD research was largely on Cascadia subduction through reflection seismology. Has worked extensively elsewhere in the world, largely in Japan with the NanTroSEIZE project at the Nankai subduction zone. Recently worked on seismic data from Cascadia COAST surveys.
He’s excited and a little scared to start the job, but is looking forward to applying his research to practical hazard mitigation in the PNW. He’s excited to broaden his research portfolio and work with people at the PNSN and is looking forward to getting to know everyone on the RAC committee as well.
Part of the challenge of coming in is not derailing the good work being done already. Harold’s looking forward to coming in and gathering input on what works, what needs to be fixed, and meeting with stakeholders to develop a vision for the seismic network.
Harold sees the PNSN as a good potential base for a subduction zone observatory. He would love to see growth into new data streams and products. The future of the PNSN should likely include a greater offshore component.
Harold’s wife will be accepting a job as an Earthlab administrator at UW, and will start in August.
<Introductions around the room, as well as remote listeners (Cecily Wolf, Wes Thelen, Lucy Walsh, Bill Perkins, Art Frankel, Tim Melbourne, Steve Hickman)>
CB Crouse: We will now proceed with the rest of the agenda
Community Reports
Ground motion issues: Project 17 & 2020 NEHRP Provisions
CB Crouse: Project 17 will feed into 2020 NEHRP Provisions. Starting in 1997, there has been a decadal meeting of engineers to guide hazard mitigation. 2017 was the last such meeting, and CB is here to report their findings.
The main issues that came out of the meeting were a plan to transition to the concept of multi-period response spectra for the national hazard map, and to revise the deterministic cap on PSHA, which are applied in high hazard area. Other additions to the national hazard mapping project discussed were physics-based models (Fault-rupture directivity and basins), site coefficients for the central and eastern US, and vertical component of motion.
The possible revisions for 2020 NEHRP would be to eliminate site coefficient tables and instead utilize the multi-period response spectra; and add 3 new site classes (Reference Rock, Very Stiff Soil, and Soft Soil). We found that at longer period (>2s), the preexisting site conditions did not match the existing response spectra and need to be replaced. This will constitute work for the next year.
Questions:
-Bill Steele: how do these new site conditions handle basins?
-Answer: The USGS has a plan for including basins, which Erin Wirth will speak to.
-Susan Chang: Is the table of N-values going to be further refined and modified?
-Answer: yes
USGS Earthquake Program Update
Erin Wirth:
A broad update of ongoing science projects here at UW:
-M9 Project: this is a joint project between UW and USGS. It covers many topics but is built upon on large-scale 3D ground motion simulations, the results of which are passed on to tsunami modelers, landslide scientists, and EMS for experimentation and planning.
-The GM simulations are now publicly available on DesignSafe.
-There was a March 2018 workshop convened by Susan Chang. The city is planning on including the basin amplification factors into the design of tall buildings.
-USGS Subduction Zone Science Initiative (spearheaded by Joan Gomberg). Has the purpose of helping us understand subduction zone processes, quantifying hazards, and forecast hazard/ increase situational awareness.
-Cascadia Recurrence Project (led by Joan Gomberg and Brian Sherrod). Some studies infer more frequent megathrust earthquakes in southern Cascadia, but other studies don’t. The goal of this project is to take a holistic examination of all these studies to understand the disagreement between them. This entails working with paleoseismologists, landslide scientists, etc.
-This project recently received a Powell Center Grant for support of meetings, work funding.
Questions:
-Paul Bodin: is Project 17 paying attention to the long period ground motion results from M9?
-Answer (CB Crouse): yes. However, the primary concern of Project 17 is to standardize/stabilize ground motion estimates and the resultant change in design specifications.
WA DNR
Tim Walsh:
Primary project has focused on Chehalis River seismic characterization. Severe flooding at Chehalis has shut down I5 regularly in recent years. State gov’t has been trying to mitigate this issue through water retention. The WGS was asked to review the seismic safety of flood retention structures on the Chehalis River.
Among other things, much thought has to go into fish lifecycle management along the Chehalis River. So far, the most cost-effective option is a “Flood Retention Only” structure, which would only be shut in the case of a very large flood.
The WGS has been doing grav/mag, geologic mapping, and geochronology surveys in the area to characterize uplift and seismic hazard along the Chehalis River.
Rattlesnake Ridge Landslide Monitoring:
-The landslide consists of a large slump just south of Union Gap, WA. Moves ~1.3ft/wk, since October, though has likely slowed down in the last few months. Has been moving into the rock quarry at its foot. It is directly adjacent to I82 and may pose a threat to nearby communities. PNSN has put out small array to monitor the slide. UO has put out nodal array on landslide as well.
Questions:
-CB Crouse: who will take Tim Walsh’s position when he retires in the coming year?
-Answer: Corina Allen (née Forson), with help from other colleagues.
OR EMS
Leland O’Driscoll (filling in for Althea Rizzo):
-ShakeAlert user symposium was held (there have been transportation and emergency management symposiums so far). Upcoming symposia for Medicine, Education, etc.
WA EMD
Bill Steele:
-An education and training document for ShakeAlert has been produced.
-CREW has been working with NEHRP and FEMA to hire a contractor for ShakeAlert training coordination, which may lead into a full-time position in the future with state EMD. Working on a pilot program for 911 services.
-Management of outreach and education used to be handled by USGS/university work group. This is expanded now: there is an emergency management workgroup which will focus on outreach to community outreach and emergency management.
Canadian Update
John Cassidy (Over Phone):
“Earthquake Monitoring, Research, and Related Developments in British Columbia”
-Canadian National Hazard Service is modernizing 150 seismic monitoring sites across Canada. Most weak-motion sites will now have 6-component strong-motion instruments, and an additional 40 stand-alone strong-motion stations. Many sites in BC will also have real-time GPS added.
-Science Updates:
-Canada is now a member of the Global Earthquake Model Foundation. It’s using OpenQuake for earthquake hazard and risk assessments.
-BC North Coast geohazards project (5yr - $5M) is now complete. 6 new seismic and GPS stations will remain operating. Final report under review and will be presented at the NEC conference this month
-Paleoseismology field work is underway on the west coast of Vancouver Island, attempting to better constrain earthquake history through time.
-other things: characterizing site effects in CN; offshore observatories and a new array of OBS will come online soon; hired a new earthquake seismologist (Andrew Schaeffer); BC Integrated Risk Assessment is complete and is under review.
-Highlighted some research showing significant measured offset on Haida Gwai from GPS.
-Research on Devil’s Mountain Fault and Queen Charlotte Fault near Victoria, BC, is ongoing both onshore and offshore.
-National Building Code of Canada 2025
-new ground motion attenuation models under development
-they are in the process of addressing lessons from recent global earthquakes (e.g., Mexico deep events of 2017)
-working on site condition characterization
-Improved characterization of subduction zones in Beaufort Sea and Winona Basin
-Canadian Cordilleran Array Proposal
-Dense seismic/GPS array will fill in the monitoring “blank space” between Alaska and Washington.
-Emergency Management British Columbia continues to oversee progress the ONC is making on the development of the EEW system.
-BC Seismic Safety Council invested $5M towards EEW for Canada.
-Paul Bodin: There is an ongoing project with ONC to exchange early warning parameters
PNSN - UW
Paul Bodin:
What has the PNSN been doing in the last year?
Budget:
-In the past year, several funding sources have ended, dropping the overall budget from $4.2M to $2.4M
-EEW: 12.9M in FY2018 +10M in one-time funds for infrastructure buildout over 2yrs; the one-time funds are currently under review at the USGS. 16M in FY2019 from the House committee, but probably no more available for buildout.
-New implementation: no funds for buildout, but 24M/yr. for operation
-CA has separately acquired 10M in FY2017, unsure for FY2018/2019
-OR has put in 1M for instrumentation
Staffing:
-~5 employees and staff left in the last year (including John Vidale)
-Added ~10 employees and support staff (including Harold Tobin)
-Tom Yelin is retiring
Data:
-Many people downloading PNSN data from IRIS
Major ANSS Initiatives:
-translation of data to SIS (Station Inventory System) is underway. ANSS-wide database of RSN hardware and station & channel metadata
-Reporting to ComCat is complete.
-AQMS is being migrated off of Oracle/Sun hardware onto Linux and PostgreSQL
Network Status:
-We use 30 compute servers to handle incoming data.
-Significant time and resources are dedicated to handling metadata and processing incoming data, maintaining and improving network.
-EEW is adding many more stations to our processing.
-How do we decide where to place EEW stations?
-We first look at a hazard map, and then decide where the majority of the sources (faults) controlling that hazard are located. For EEW, we want to place stations as close to these sources as possible.
-Hanford: Hanford has provided funding that we used to place 13 6-component strong motion sensors in the reservation. This has significantly improved data coming from Hanford.
Volcano Monitoring Concerns:
-Kilauea eruption has given us many lessons on where we can improve our own large event response plan
Netquakes
-going well
Major Challenges in the coming year:
-Managing network growth
-subcontracting various elements where possible
-site modularization- so we can more easily outsource work
-Transition away from analog stations/telemetry
-Coordinating roles (i.e., ANSS vs. EEW vs. “other”)
ShakeAlert Operational Status
Renate Hartog:
-ElarmS-3 algorithm significantly reduces the number of false alerts (-90%) in the last year
-FinDer is the new (March 2018) finite fault algorithm that considers the time-varying distribution of strong ground motion observations to predict the severity of ground motion along a perceived linear trend (i.e., for rupture propagating along a large fault).
-In the last 3 months, there have been 147 DM alerts with M >=3.0
-10 false alerts: 9 from ElarmS3, 1 from Onsite, and 0 from FinDer.
-13 extra alerts for already-alerted events (bug)
-False alert rate is ~15%; the goal is to reduce this to 10%
-There is a limited public roll-out is planned for later this year.
-By the end of the year, if a pilot user is ready to alert their customers, they will be allowed to do so.
-Kickoff media event at BART on August 2nd.
-Beforehand, ElarmS3 and Onsite waveform filtering will be combined into EPIC algorithm. eqInfo2GM will be used to generate ground motion contour and map messages.
Questions:
-when will apps be available for phones?
Answer: it’s not really practical at the moment to send a large number of warnings quickly. There is a push to have cell phone providers update standards to facilitate faster warnings in the future.
-Tim Walsh: Does Harold know how to use Facebook?
-yes, but is not as prodigious a poster as was the previous PNSN director!
PNSN ShakeAlert R&D, GNSS
-G-FAST utilizes real-time GPS displacements to characterize large surface displacements for early warning. The UW team is working on developing a single Geodetic algorithm for handling, analyzing data on the fly during a large earthquake. We have added a couple dozen new stations with funding from the Moore Foundation; we currently have funding for 5-10 more stations.
-Working with Tsunami Warning Centers to ingest GNSS data for near-field tsunami warning (collaboration with NASA, NOAA, etc.), implemented in NZ already.
-We have published a database of GNSS/Strong motion data from global events.
Questions:
CB Crouse: what is the sampling rate on our GNSS?
-1Hz
PNSN - CVO Update
Wes Thelen (Over Phone):
Rainier Lahar Detection System:
-Added several stations on the Puyallup River, Carbon River, Western side of Rainier.
-Will add stations to Nisqually River. Permitting environment here is more difficult (stations will be in national park)
Looking to update stations on Mt. Hood and Glacier Peak
-Permits are currently in limbo.
The eruption of Kilauea has taken up a lot of time from CVO staff (at least 6 CVO people are currently in Hawaii, and several are working on Kilauea data from CVO remotely). This is the first eruption where we have been able to demonstrate remote capabilities and inter-observatory collaboration. This is good, as HVO is currently abandoned due to volcanic hazard (it’s falling into the caldera).
-NVEWS (National Volcano Early Warning System) has passed the Senate and is awaiting passage in the House due to the Kilauea eruption. This prioritizes monitoring resources based on threat level and eruption status.
-Will likely update communication, operation procedures in wake of Kilauea eruption. Will work with PNSN to apply these locally.
PNSN-UO Update
Leland O’Driscoll:
-Collaboration remains strong between UO and UW. This can be attributed to collaborative efforts in station, data management. DOGAMI has funded 29 stations worth of equipment, 13 of which are installed, 2 more by the end of the month. 12 more sites worth of equipment has arrived at UW. Many of these sites will be collocated with GNSS.
-There is an ongoing collaboration with transportation department in OR
-State of Oregon has ShakeAlert committee, headed by Lucy Walsh.
-The goals of this system largely parallel overall system but incorporate goals of long-term seismic resilience in OR.
PNSN – ShakeAlert Outreach Update
Bill Steele:
-RH2 Engineering and local water resources are collaborating on adding ShakeAlert cutoffs in dams. Will detail technology in a PBS show, as well as have a media rollout.
-Collaborating with WashDOT to figure out how to incorporate alerts into both road and ferry resources.
-Looking to add power, medical, other utilities uses in the near future.
Lunch Discussion
facilitated by Bill Steele and Leland O’Driscoll
Prompt:
“What is required to implement ShakeAlert in the region successfully?
The “soft release” of ShakeAlert begins in August of this year. Currently it appears likely that alerts from this release will be unavailable in Washington, largely due to resistance from State EMs. How should we message this? What steps are required to produce, and what outcomes desired from, WA state support for ShakeAlert. Can the private sector be induced to help?”
Q=question, A=answer, C=comment
-C: There will be some money available for research on how to properly prepare
-Q: What has been found in places where this technology has already been implemented? The technology is not new, what has been done elsewhere?
-A: we have had people go to Japan and observe the well-funded, ubiquitous system and how it is presented to people, as well as in NZ.
-A: Part of the challenge is that the protocols in state and government. The message changes depending on where you are in the state (if it’s a megathrust event). Some locations will have <30s of warning, and others will have >1min. The warnings need to be different between these locations.
-A: PNSN focuses primarily on developing accurate alerts, and now strategies are needed for how these alerts are used by EMDs.
-A: EMDs want at least 6mos funded public education before public rollout.
-Q: Has anyone figured out how much money would be needed to do educational outreach on the scale it’s needed?
-A: Leland: hundreds-of-thousands to low-millions.
-C: Depending on the location and the amount of time, the messaging will likely need to be different. That messaging and the messaging protocol needs to be established before the service is rolled out.
-C: Let’s not treat early warning like it’s an unpleasant mandate, it’s still an exciting, helpful technology.
-C: The community needs to have confidence in the messaging for it to be effective
-C: One of the reasons of EM’s are hesitant to implement this is b/c they are required to act on alerts (“duty to warn”). If they receive an alert and don’t know what to do with it, they may have failed on their duty.
-Q: Are the pilots targeting different disciplines?
We have strong outreach to water and sewer agencies in Washington and Oregon. In the transportation sector, WSDOT and ODOT have initiated pilot projects. We have reached out to Sound Transit but have not had any success. We will be working with Schools, hospitals, and hopefully other utilities, in 2018.
-A: we have tried to reach out to WashDOT, but have not had a lot of luck.
-C: At some point later this year, there will likely be a hubbub about an earthquake early warning system. It will come up that there will be a large rollout in Los Angeles among city employees, but not in the PNW, and we need to figure out how to address that.
-C: We need to make very clear what “limited” public rollout means, and make sure that this is consistent across organizations and in the media.
Leland presents ShakeAlert “Products”
-We will not be presenting large-scale public alerts later this year. This should be made clear.
-Recommended thresholds for reporting are M5+ or MMI4+. The region of rollout should be areas approved by state emergency managers after public training has been completed.
-Ultimately the Wireless Emergency Alerts will be used, but scalability is not adequate at the moment.
-Follow-Up messages: After a “true” alert, there will be a post-event summary put out online
PNSN Related Topics
URM initiatives
Susan Chang:
Final report on Seattle URM distribution published in 2017. Recommends widespread updates to URMs throughout the city. Recommends timeline for completion for upgrades: 7 years for critical facilities and 13 years for others.
There is no policy in place at the moment to make upgrades mandatory. National Development Council is helping the city gather information on how to finance upgrade options via nonprofits and other sources.
Questions:
-What retrofit standard did the report adopt?
-Answer: Modified bolts plus
M9 Updates
Alison Duvall:
The M9 project has the goal to reduce catastrophic potential of Cascadia earthquakes through advances in hazard assessment and adaptive planning. There are many stakeholders both in and outside of the university.
The centerpiece of this project has been the 3D ground motion simulations, spearheaded by Erin Wirth and Art Frankel. These allow for predictions of downstream effects.
-We are currently looking at predicted coseismic landsliding from the modeled strong ground motion, as well as the mapping and dating of coseismic Cascadia landslides.
-Alex Grant has found that there is a significant difference in wet vs dry conditions and the resultant landslide risk
-Sean LaHusen is looking at coseismic landslide record on the Oregon coast.
Questions:
-have you found an A.D. 1700 landslide yet?
-not yet
-Susan Chang notes that the city has been updating the known-landslide database that will be shareable with the public in the near future.
NEHRI/RAPID facility at UW
Jeff Berman:
“The NHERI RAPID Facility”
NHERI is a suite of field equipment for deployment after a large natural disaster.
The mission of RAPID is to collect a large amount of high-resolution, open-source disaster data collected using systematic data acquisition practices. It is hoped that the data will be used to better prepare for natural disasters
-Current activities include acquiring, maintaining and operating data collection equipment. This includes seismic, wind/storm, interviewing, imaging, and processing equipment.
-more info at https://rapid.designsafe-ci.org/
Improving School Resilience, State Survey
Tim Walsh:
-In 2012, we did a pilot program to test school resilience at 2 Washington schools. From this, they estimated that it would cost $13M-16M to do a full state survey and take 8yrs. Last year we received ~$2M to do this. That allows us to do ASCE41 surveys for ~220 school buildings. There is a State School Seismic Safety Committee to look at the problem of doing school surveys. Reid Middleton is the contractor chosen to conduct the surveys. 20 of the 220 schools will be looked at for retrofitting concepts. Must also do 5 fire stations that are within 1 mile of the schools. Surveying and analysis was supposed to be completed by June of 2019, but funding delays at state legislature have slowed this down somewhat.
-Between the schools, there is a mix of urban/rural, school age, and hazard sources.
-More details on DNR website.
Questions:
-Is a list of the schools online?
-Answer: not yet. Still negotiating which schools will be used.
SZ4D and the USGS SZI
Paul Bodin:
-Moore Foundation has put funding into offshore project. This is largely spearheaded by Will Wilcock and David Schmidt. This would involve putting a cable offshore for monitoring earthquake and tsunami hazard. We are about to put a white-paper out that details a meeting held 2 years ago covering the issues and challenges of an offshore network. Paul refers questions to Will and David.
-SZ4D is a community proposal to establish a monitoring initiative for subduction zones. NSF proposal involves a research coordination network. Harold Tobin is the PI. There is also USGS side being developed as well; this is moving forward a little faster. This will look at the science underlying the hazard.
Questions:
-How many years will the SZ4D project be?
-Answer: unsure. This proposal is not to establish the facility, but to establish the plan.
Discussion
CB Crouse: Are we headed in the right direction, what course corrections do we need?
Bill Steele: This year, with Heidi and John leaving, we only have one full-time professor at ESS devoted to seismology (Ken Creager). It is somewhat of a crisis, as professorships are important for building a research program, bringing in graduate students, and building institutional support for the PNSN.
Leland O’Driscoll: UO now has 5 seismologists, so maybe it is worth bringing that PNSN brain trust southward. This will be better for strengthening collaboration.
Paul Bodin: PNSN has a lot of seismologists (6), as does the USGS on campus. They are not paid by the school, but contribute to research nonetheless. However, this is putting stress on the staff.
Tim Walsh: Is Heidi’s position going to be filled by a seismologist?
Paul: The department establishes hiring priority. Heidi’s position was not as high priority as the director position. The discussion regarding her position has not yet occurred on a department level.
CB Crouse: What courses are being taught at UW on seismology?
Paul: a wide range of courses at both the undergrad and graduate level.
Wes Thelen: It’s telling that there is a lack of new graduate students coming in to UW. Wes would like to see more prioritization of volcano related sciences including seismology in the ESS program, so more graduate students are entering the research pipeline.
Paul: PNSN focus on ShakeAlert and ANSS priorities has likely shifted attention away from volcano monitoring.
Bill: UO has received $10M gift for volcano funding and now leads the UW in Seismologists and Volcanologists on faculty and the USGS is turning to them for research support. The UW and ESS Department seems to be suffocating a world class program by elimination of critical faculty positions through attrition.
CB Crouse: What are the implications of having $0 for buildout?
Paul: As he understands it, there is now funding coming from individual states that can be used for that, in particular CA, but also OR. The USGS is interested in helping states implement new stations.
CB Crouse: Some of the instrumentation that we have in Seattle is USGS, and some is for ShakeAlert. Is this data available in such a way that engineers can look at it directly after an earthquake? Engineers will likely want the data for seeing how safe their buildings are.
Paul: the raw data is immediately available from the IRIS archives, though this is not necessarily good for application by engineers. There are some products on the table that will be available in the near future for producing more engineering-friendly data.
Bill Steele: as we are densifying the network, perhaps we could use guidance from the engineering community about where to place new stations.
CB Crouse: as the structural engineering community is somewhat skeptical of including basin effects in codes, it would be nice to have more actual data in the basins to back up numerical simulations.
Art Frankel: Since Nisqually, we have had lots of observations documenting the amplification in the basin. We still have an urban seismic array in Seattle and Bellevue. Observationally, we have a fairly consistent record of amplification. We could have more stations downtown, on Capitol Hill, and First Hill, however.
Susan Chang: She has heard from structural engineers that they would like to have a grace-period for implementing changes due to M9 results. Some felt that we should wait until basin effects are included in national maps before implementing here; others would like more simulations in Seattle to build on information.
Art: For the 2018 maps, basin effects will be included in the national maps for LA, San Francisco, and Seattle. These will be implemented using depth to 2km/s.
Paul: how is depth to 2km/s predicted? And how are the boundaries of the basin defined.
Art: Seattle’s were determined from the SHIPS survey. The outline of the Seattle basin was determined using geology and gravity surveys; it is bounded by the Seattle Fault and extends north to Edmonds.
CB Crouse: how big is the issue of amplification in the Portland Basin?
Art: We do not see the same degree of amplification; it is not quite deep enough. However, the Tualatin basin does see significant amplification (Beaverton, Hillsborough).
CB Crouse: would more stations in Seattle help improve the velocity model?
Art: we are looking at using ambient noise data at the moment to improve velocity structure. This looks promising.
Bill Steele: Can we use the INTEL Hillsborough strong motion stations for data?
Jeff Soulages: not at the moment.
Jeff Soulages: What would USGS need to do more studies in the Tualatin Basin?
Art: We would need more broadband stations. Grids of broadband stations recording in urban areas (1km spacing) would allow for a lot of beneficial science.
Paul: would those be permanent?
Art: permanent would be nice, but 3-4years would be sufficient.
CB Crouse: I am interested in the frequency of large quakes in southern Cascadia. Will this affect hazard estimates in the future (2020)?
Art: it is an important question. The survey is trying to do a pilot project to better understand the turbidite sequence in this area. It will likely take longer than until 2020.
Susan Chang: We have at least 1 consultant that wants to do non-ergotic PSHA (probabilistic seismic hazard analysis)
Should we avoid that?
Art: Some argue that if we include basin terms, we should lower the sigma for the data. For one, we don’t know how much to lower that sigma, but just based on the natural variability in the basin effect, Art recommends that lowering the sigma is not advisable.
John Cassidy: You mention the volcanic monitoring is a hazard. What do you see is needed based off Kilauea and Fuego eruptions?
Paul: NVEWS is a good resource. Future faculty hires should focus on volcano expertise at ESS; attracting top-notch students is very important as well.