UUSS 2015 Annual Report

UUSS Annual Report 2015

2015 Annual Report

2015 has been another vibrant and productive year for the University of Utah Seismograph Stations (UUSS). Our longstanding partnership with the United States Geological Survey (USGS) was extended with a new, 5-yr cooperative agreement from the USGS Earthquake Hazards Program. This award ensures that earthquake monitoring in Utah will continue to operate with state-of-the-art equipment and software at least through 2020. Congratulations to the UUSS staff for all their hard work on the USGS proposal, it was truly a team effort.

The legacy of UUSS in earthquake monitoring and research was recognized in 2015 as two former UUSS Directors received prestigious awards for career accomplishments. Research Professor Emeritus Dr. Walter J. Arabasz received the 2015 Alfred E. Alquist Special Recognition Medal from the Earthquake Engineering Research Institute, while Professor Emeritus Dr. Robert B. Smith received the 2015 Paul G. Silver Award from the American Geophysical Union. Congratulations to Walter and Bob for the leadership and service they have provided to the seismological community over the last several decades.

UUSS developed a new monitoring capability in 2015 with the acquisition of nearly 50 new wireless seismographs. The instruments were purchased in collaboration with Dr. Fan-Chi Lin and other University of Utah geoscientists, and will allow for the imaging of shallow Earth structure at a very small scale as well as the detection of small aftershocks that follow regional earthquakes. Please look inside to read about one of the first experiments carried out with the new instruments.

We expect great new things in 2016 as well. Keep an eye out for an updated UUSS web page and expanded social media presence. We also look forward to a celebration of the 50th anniversary of UUSS, in April 2016.

Scenario for a Magnitude 7.0 Earthquake on the Wasatch Fault–Salt Lake City Segment: Hazards and Loss Estimates

Pankow, K., W. J. Arabasz, R. Carey, G. Christenson, J. Groeneveld, B. Maxfield, P. W. McDonough, B. Welliver,
Segment: Hazards and Loss Estimates, Earthquake Engineering Research Institute, Utah Chapter, 53 p.

Paleoseismology of the Promontory Segment, East Great Salt Lake Fault

Dinter, D. A., and J. C. Pechmann (2014). Paleoseismology of the Promontory Segment, East Great Salt Lake Fault, U.S. Geol. Surv. Final Technical Rept., Award No. 02HQGR0105, 23 pp, http://earthquake.usgs.gov/research/external/reports/02HQGR0105.pdf
ABSTRACT
With funding from this project, we collected 367 km of high resolution seismic reflection data in the Great Salt Lake in 2003 and 2006: 205 km in the north arm and 162 km in the south arm, where the north and south arms are defined as the parts of the lake north and south of the railroad causeway, respectively.  Because the quality of the north arm data that we obtained was insufficient to meet the goals of the project, we collected an additional 380 km of data with new, state-of-the-art instrumentation in 2009 and 2010: 160 km in the north arm and 220 km in the south arm. The 2009 fieldwork was part of a collaborative industry-funded study. The 2010 field work was carried out using boat and equipment time that became available after the successful completion of a seismic reflection study in Utah Lake for another USGS/NEHRP-funded study.
We used the seismic reflection data to map the Great Salt Lake fault (GSLF) and associated subsidiary faults in the north arm of the Great Salt Lake and to revise an analogous map for the south arm of the lake that we constructed for a previous USGS/NEHRP-funded project. We also mapped the trace of the Carrington fault, another major normal fault in the Great Salt Lake, using our seismic reflection data and high-resolution bathymetry data for the lake.  Based on the geometry of our mapped surface trace for the GSLF, variations in the amount of lakebed offset along this fault, and other evidence for recency of faulting, we hypothesize that the GSLF consists of the following four segments from north to south (with end-to-end length measurements): the Rozel segment (≥ 18 km), the Promontory segment (≥27 km), the Fremont Island segment (24 km), and the Antelope Island segment (35 km).
Seismic reflection profiles across the GSLF in the north arm show clear evidence for individual paleoearthquakes in the form of stratigraphically limited subsidiary faults and monoclines and coseismic bedding rotations adjacent to the fault. Based on these types of features, we have identified seismic event horizons for two or three paleoearthquakes on the Rozel segment and two or three paleoearthquakes on the Promontory segment , all within ~8 m of the lake bottom.  A possible fourth Promontory segment earthquake is suggested by the higher fault scarps along this segment. The earthquake event horizons that we have identified in this study can be cored and dated to establish a paleoearthquake history for the Rozel and Promontory segments of the GSLF. In the meantime, based on comparisons with the depths of dated event horizons on the Antelope Island and Fremont Island segments, it seems reasonable to assume that the average recurrence interval of 4200 ±1400 years that we have determined for these two segments is also applicable to the Rozel and Promontory segments

UUSS 2014 Annual report

uuss_ar2014 cover2014 Annual Report

Dear Friends,
It is a pleasure to present you with the 2014 Annual Report of the University of Utah seismograph Stations (UUSS). Reflecting on recent UUSS accomplishments, I was struck by the importance of partnerships in pursuing our dual mission of academic research in earthquake science, and communication to the residents of Utah of the latest information on earthquake risk.
As always, a key UUSS partner in 2014 was our home academic unit, the Department of Geology and Geophysics. A nice example of the support shown by our department is the recent hire of a new tenure-track faculty member in seismology, Dr. Fan-Chi Lin. Although Dr. Lin’s expertise is in seismic imaging, he has already expressed interest in collaborating with UUSS faculty on projects related to earthquake science in Utah and Yellowstone.
A second important UUSS partner is the Utah Division of Emergency Management (DEM). This agency administers Utah’s earthquake program and has the responsibility for mitigating and responding to earthquake hazards in the state. The DEM earthquake program funds the UUSS traveling earthquake exhibit, which visited 25 elementary and middle schools throughout Utah in 2014. The DEM also provides financial support for the Utah Seismic Safety Commission, the state’s official earthquake advisory board.
A third partner that is essential to the success of UUSS is the United States Geological Survey (USGS).  The USGS routinely and consistently supports UUSS by providing the latest seismic equipment—and the funding to operate and maintain this equipment. In 2014, USGS funding enabled over 115 seismic stations to be operated in the State of Utah. As with all of our
seismometers, these instruments operate 24 hours a day, 7 days a week, and transmit data to the UUSS earthquake information center within seconds of it being recorded.
Many people at the university, and within state and federal agencies, contribute to the success of UUSS. To learn more about all of our partners, and the achievements they have contributed to, please take a few moments to browse through this year’s Annual Report.

UUSS 2013 Annual Report

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University of Utah Seismograph Stations (UUSS) had another busy year in 2013.

The professional highlight was hosting the annual meeting of the Seismological Society of America (SSA), April 17-19, at the Salt Palace Convention Center in downtown Salt Lake City. The SSA is the world’s premier scientific society dedicated to the study of earthquakes. UUSS personnel served on the organizing committee, led a Town Hall Meeting, moderated several of

the scientific sessions, and contributed to 12 scientific presentations. For some UUSS students, it was the first time attending a professional meeting and they were excited to meet scientists whom they had previously known by reputation only.
During 2013 UUSS detected and located about 6,000 earthquakes in the Intermountain West. This region includes all of Utah and Yellowstone National Park, as well as parts of Arizona, Colorado, Idaho, Montana, and Wyoming. Although none of the earthquakes were large enough to cause significant damage, careful documentation of these events allows us to better define
the locations of active faults and to estimate seismic hazard in the region more precisely. The geologic record clearly indicates that magnitude 6.5-7.5 earthquakes have repeatedly occurred along the Wasatch fault in areas of Utah that are now densely populated.
In addition to earthquakes, our seismic network often observes other “exotic” sources of seismic energy. Such a source occurred on the evening of April 10, 2013 when the northeastern wall of the Bingham Canyon, Utah open-pit copper mine collapsed in two distinct landslides separated by about 90 minutes. The combined episode was the largest non-volcanic landslide to occur in North America in modern times. Seismic waves were well recorded thousands of kilometers away from the mine, and at least 16 tiny earthquakes were triggered by stress changes associated
with the landslide. Owing to rigorous geotechnical monitoring, the mine operators were able to accurately predict the timing of the landslide and so avoid casualties.
A second exotic seismic source occurred on July 31 at 7:30 p.m. (local time) when the Steamboat Geyser in Yellowstone National Park erupted, sending water 200-300 feet in the air. Signals recorded at a nearby seismometer showed energy lasting for over two hours as steam poured out of vents following the initial eruption. Notably, acoustic energy from the eruption was recorded by one of the infrasound stations located in the park.
In 2014 the students, faculty, and staff of UUSS will continue to monitor earthquake activity in the Intermountain West and to raise awareness of the seismic hazard in the State of Utah. Academic research will focus on a range of topics including the rupture properties of large earthquakes, earthquake swarm and aftershock sequences, seismicity induced by mining and
other anthropogenic activities, as well as producing better images and models of the geological structure beneath Utah and Yellowstone.

UUSS 2012 Annual Report

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UUSS Annual Report 2012

It is my pleasure to present the 2012 Annual Report of the University of Utah Seismograph Stations (UUSS).

Working with state and federal partners, we monitor seismicity in much of the Intermountain West, we carry out fundamental academic research on earthquakes, and we educate and inform the public about the risk from earthquakes. I hope that this inaugural annual report provides an informative update on our recent progress in these areas.

The operational highlight of 2012 was the installation of a state of-the-art software package developed by the Advanced National Seismic System (ANSS). ANSS Quake Monitoring System (AQMS) will provide UUSS new flexibility in detecting, locating, and publicizing earthquakes. A close second was the development of an in-house database containing all digital UUSS broadband and short-period seismic data recorded since 2001.

In 2012 UUSS scientists published academic papers on a diverse range of topics that included a new catalog of moment tensors for Utah earthquakes; modeling of infra sound recordings of the 2011 Circleville, Utah earthquake; simulations of ground motion in Utah expected for an M7 earthquake along the Wasatch fault; and the inference of short-period rupture properties of three recent great earthquakes in Peru, Chile, and the Indian Ocean.

On a rainy day in April 2012, UUSS also participated in the first ever Great Utah ShakeOut to help raise awareness of earthquake hazard in Utah. And the UUSS traveling earthquake exhibit visited over 50 schools throughout the state.  Although the next year looks to be a challenging environment in terms of funding, I am confident that the hardworking students, faculty, and staff of UUSS will maintain operational and academic excellence. A few of the exciting things to look forward to in 2013 include:

  • Starting February 1, 2013, UUSS will begin a new 3 year cooperative agreement with the U.S. Geological Survey (USGS) for monitoring and characterizing earthquakes in the Yellowstone region, one of the most geologically dynamic places in the world and a site of previous supervolcano eruptions.
    Professor Emeritus Robert B. Smith will be retiring from his role as the principal investigator of this project after three decades, but will continue to be involved with the UUSS Yellowstone work.
  • On April 17-19, 2013, UUSS will welcome the annual meeting of Seismological Society of America to Salt Lake City. This is the world’s most prestigious professional society dedicated to earthquake science.
  • Christine Gammans, first recipient of the UUSS graduate fellowship honoring Director Emeritus Walter J. Arabasz, will graduate with an master’s degree in geophysics and begin her career with Chevron in August.

As we approach the 50th anniversary of the founding of UUSS, we are mindful of many whose contributions have laid a solid foundation for the Seismograph Stations. We look forward to adding to that legacy in the year ahead.

Ground-motion recording and analysis of mining-induced seismicity in the Trail Mountain Area, Emery County, Utah

Arabasz, W.J., S.J. Nava, M. k. McCarter, and K. L. Pankow (2002) Ground-motion recording and analysis of mining-induced seismicity in the Trail Mountain Area, Emery County, Utah, technical Report, University of Utah Seismograph Stations, Salt Lake City, Utah, 162pp.

Seismic characterization of coal-mining seismicity in Utah for CTBT monitoring

Arabasz, W. J. and J. C. Pechmann (2001). Seismic characterization of coal-mining seismicity in Utah for CTBT monitoring, Technical Report UCRL-CR-143772, Lawrence Livermore National Laboratory, Livermore, California, LLNL Research Agreement No. B344836, 122 pp., including tables and figures.