Origins of a National Seismic System in the United States
This historical review traces the origins of the current national seismic system in the United States, a cooperative effort that unifies national, regional, and local-scale seismic monitoring within the structure of the Advanced National Seismic System (ANSS). The review covers (1) the history and technological evolution of U.S. seismic networks leading up to the 1990s, (2) factors that made the 1960s and 1970s a watershed period for national attention to seismology, earthquake hazards, and seismic monitoring, (3) genesis of the vision of a national seismic system during 1980–1983, (4) obstacles and breakthroughs during 1984–1989, (5) consensus building and convergence during 1990–1992, and finally (6) the twostep realization of a national system during 1993–2000. Particular importance is placed on developments during the period between 1980 and 1993 that culminated in the adoption of a charter for the Council of the National Seismic System (CNSS)—the foundation for the later ANSS. Central to this story is how many individuals worked together toward a common goal of a more rational and sustainable approach to national earthquake monitoring in the United States. The review ends with the emergence of ANSS during 1999 and 2000 and its statutory authorization by Congress in November 2000.
Arabasz, W.J., Pechmann, J.C., and Burlacu, R., 2016, A uniform moment magnitude earthquake catalog and background seismicity rates for the Wasatch Front and surrounding Utah region: Appendix E in Working Group on Utah Earthquake Probabilities (WGUEP), 2016, Earthquake probabilities for the Wasatch Front region in Utah, Idaho, and Wyoming: Utah Geological Survey Miscellaneous Publication 16-3, variously paginated.
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.
Electronic Supplements (.xlsx)
E-1. Best-Estimate Moment Magnitude (BEM) Earthquake Catalog
E-2. Moment Magnitude Data
E-3. Merged Subcatalog A, Jan. 1850-June 1962
E-4. Merged Subcatalog B, July 1962-Dec. 1986
E-5. Merged Subcatalog C, Jan. 1987-Sept. 2012
E-6. Worksheets for Mobs, M~, Mpred (I0)
E-7. Worksheets for Xnon, Xmix (Subcatalogs A, B)
E-8. Worksheets for Xvar, Xi (Subcatalog B)
E-9. Worksheets for Xvar, Xi (Subcatalog C)
E-10. N* Counts for the WGUEP and Utah Regions
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.
Liu, Q., K. D. Koper, R. Burlacu, S. Ni, and F. Wang (2015). Observations of teleseismic body waves (P,SV,SH) in microseisms recorded by a large aperture array in China, Abstract S41B‐2757.
Koper, K. D., and R. Burlacu (2015). Location of P‐wave microseism sources via back‐projection of large aperture seismic array data, 26th International Union of Geology and Geophysics General Assembly, Prague, Czech Republic, June 22 ‐ July 2.
Batchelor, C. E., K. D. Koper, and K. L. Pankow (2015). Characterization of seismic swarms in Utah, Seism. Res. Lett. 86, 681.
Smith, R. B., J. Farrell, and C. M. Puskas (2015). Mantle‐crust volcanics and geodynamics of the Yellowstone hotspot from seismic and GPS imaging and earthquake swarm magmatic interaction, Abstract V33‐08.
Puskas, C. M., C. M. Meertens, W.‐L. Chang, J. Farrell, and R. B. Smith (2015). A history of geodesy in Yellowstone National Park and the legacy of Robert B. Smith, Geological Society of America, Abstracts with Programs, 47(6), 4.