I am happy to report the University of Utah Seismograph Sta- tions (UUSS) had another exciting and productive year in 2017. Thanks to all of you who support and promote our mission of reducing the risk of earthquakes in Utah through research, edu- cation, and public service.
An Mw 5.3 earthquake on Sept. 2, 2017, in southeastern Idaho
reminded us that we absolutely do live in earthquake country.
Thankfully, this earthquake caused little damage, but its shaking
was felt throughout northern Utah, as far south as Provo. UUSS
responded to the earthquake by partnering with the U.S. Geo-
logical Survey and the Idaho Geological Survey to deploy a tem-
porary array of seismographs in the source region. Using these
data, we detected and located over 1,000 aftershocks in the two
months following the mainshock. This allowed us to map out a
previously unknown fault system.
UUSS also recorded enhanced seismicity in Yellowstone Na-
tional Park during 2017. Between June 12 and Sept. 30, a swarm
of over 2,400 earthquakes was recorded in the Maple Creek re-
gion of Yellowstone. The largest event in the swarm was an Mw
4.4 earthquake on June 15 that was widely felt throughout the
park. Although earthquake swarms in Yellowstone are common,
this was the second longest swarm ever recorded. Yellowstone
earthquake swarms are often related to the movement of fluids in
the crust and usually do not portend a volcanic eruption; howev-
er, it remains important to monitor them closely.
In 2017, UUSS continued working with the University of Utah
team vying to host the Frontier Observatory for Research in Geo-
thermal Energy (FORGE). This project is sponsored by the U. S.
Dept. of Energy and aims to build a facility for developing tech-
nologies related to enhanced geothermal energy production. The
UUSS FORGE effort is led by Prof. Kris Pankow and is focused
on quantifying the seismic hazard near the proposed FORGE site
in Milford, Utah. Utah is one of two finalists for this project, and
the winner will be announced in 2018.
We look forward to another exciting year in 2018. I encourage
you to visit our web page at quake.utah.edu to stay up-to-date on
our initiatives and products as well as to find out about the lat-
est seismic activity in Utah and Yellowstone. You can also follow
UUSS on Twitter with the handle @UUSSquake.
The Utah Geological Survey (UGS), University of Utah Seismograph Stations (UUSS), and Utah Division of Emergency Management (UDEM) recently published the Utah Earthquakes (1850–2016) and Quaternary Fault Map (UGS Map 277). The new map shows earthquakes within and surrounding Utah from 1850 to 2016, and faults considered to be sources of large earthquakes.
The faults shown on the map are considered geologically active, have been sources of large earthquakes (about magnitude 6.5 and greater) during the Quaternary Period (past 2.6 million years), and are the most likely sources of large earthquakes in the future. Most of the small to moderate-sized earthquakes on the map are “background” earthquakes not readily associated with known faults and too small to have triggered surface faulting (under about magnitude 6.5).
There is a 57% probability (over 1 in 2 chance) that a magnitude 6.0 or greater earthquake will occur in the Wasatch Front region in the next 50 years. To address this threat, the Utah Earthquake Program, consisting of the UGS, UUSS, and the UDEM, developed the map so the public could more fully understand the hazard from earthquakes and faults, as well as the resulting risk to property, infrastructure, and life safety in Utah. Users of the map will be able to determine past earthquake locations and relative magnitudes (size), along with the locations of active faults and the timing of their most recent movement.
The database for the seismicity plotted on the map, together with explanatory information, is provided in a companion report:
Arabasz, W. J., Burlacu, R., and Pechmann, J. C., 2017, Earthquake database for Utah Geological Survey Map 277: Utah earthquakes (1850–2016) and Quaternary faults: Utah Geological Survey Open-File Report 667, 12 p. plus 4 electronic supplements, available as a PDF download.
The electronic supplements include the data for the seismic events plotted on the map, which are listed in two separate catalogs, each in the form of a Microsoft Excel workbook and an ArcGIS feature class within a file geodatabase. The catalog files are available for download.
In April of 2016 the University of Utah Seismograph Stations (UUSS) celebrated the 50th anniversary of its creation as an organizational unit within the University of Utah. We celebrated this milestone with a party honoring the founding director, Dr. Ken Cook, and the unveiling of a new historical display just outside the Rio Tinto Earthquake Information Center. The ceremony was well attended by current and former UUSS employees, colleagues in the College of Mines and Earth Sciences, representatives of sister agencies in the Utah Earthquake Program, members of Dr. Cook’s family, and many other friends of UUSS. Here’s to another 50 years of reducing the risk from earthquakes in Utah through research, education, and public service.
2016 was also a year of transition for UUSS. Our administrative manager, Martha Knowlton, retired after 14 years of service. We will miss Martha’s attention to detail, professionalism, and strong work ethic. UUSS communications specialist Sheryl Peterson, who has worked in various capacities for UUSS since 1989, also left in the fall of 2016. Sheryl’s competence, cheerfulness, and organizational skills will serve her well as she pursues a new career as director of advancement operations at Southern Virginia University. We will also miss Katherine Whidden, a research scientist, student mentor, and the UUSS public information officer, who left in 2016 (ending a five-year stint with UUSS) to travel the country in an RV with her husband, John. In other news, Cindi Meier, who worked at UUSS during 1994-1999, agreed to return as our new full-time administrative officer. In 2016, we also welcomed Dr. Hao Zhang to UUSS as a post-doctoral research scientist focusing on the detection and location of sequences of very small earthquakes.
We look forward to an exciting new year in 2017. I encourage you to visit our revamped web page at quake.utah.edu to stay up- to-date on our new initiatives and products as well as to nd out about the latest seismic activity in Utah. You can also follow UUSS on Twitter with the handle @UUSS_Quake_Info.
This appendix to the report by the Working Group on Utah Earthquake Probabilities (2016) describes full details of the construction and analysis of a refined earthquake catalog and the calculation of seismicity rates for the Wasatch Front and surrounding Utah region. The earthquake catalog covers the period from 1850 through September 2012. The catalog region extends from lat. 36.75° to 42.50° N and from 108.75° to 114.25° W. A uniform moment magnitude, M (and quantified magnitude uncertainty), is determined for each earthquake in the catalog.
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.
West, M., S. Bilek, P. Boden, G. Kent, K. Koper, W.‐Y. Kim, N. Ruppert, V. Tsai, and J. Vidale (2015). Tracking North America: Long‐term Observation to Build on the Legacy of USArray, whitepaper for workshop on Future Seismic and Geodetic Facility Needs in the Geosciences, Leesburg, Virginia, May 4‐6, pp. 1‐2.
Roten, D., K. B. Olsen, and J. C. Pechmann (2015). Numerical simulations of Wasatch fault earthquakes, in Proc. of the Basin and Range Province Seismic Hazards Summit III, Salt Lake City, Utah, 12‐17 January 12‐17, W. R. Lund (Editor), Utah Geological Survey Misc. Publ. 15‐5, CD, 5 pp.
Dinter, D. A., and J. C. Pechmann (2015). Paleoseismology of the northern segments of the Great Salt Lake fault, Utah, in Proc. of the Basin and Range Province Seismic Hazards Summit III, Salt Lake City, Utah, January 12‐17, W. R. Lund (Editor), Utah Geological Survey Misc. Publ. 15‐5, CD (electronic poster).