Glenn Rix, Ph.D. and Melissa (Missy) Setz, P.E. (Georgia) were among the co-leaders to the report, entitled "Geotechnical Reconnaissance of the December 12, 2018 M4.4 Decatur, Tennessee Earthquake" that was published on April 4, 2019.
Other co-leaders were Timothy C. Siegel (Dan Brown and Associates PC) and Shahram Pezeshk (University of Memphis).
Glenn is a Senior Principal Geotechnical Engineer based in Georgia with more than 30 years of experience focused on the areas of geotechnical earthquake engineering and engineering seismology. His practice includes seismic hazard and risk assessment and mitigation for civil infrastructure.
Melissa is a Geotechnical Engineer based in Georgia focused on characterization and remedial investigations; geotechnical engineering quality control practices; and implementation and compliance. Her professional experience includes a broad range of expertise in geotechnical engineering on projects for commercial, industrial, and federal clients.
The report presents the Geotechnical Extreme Events Reconnaissance (GEER) Association team's documentation of earthquake conditions and field observations made during a field reconnaissance visit on December 20, 2018, and a summary of second-hand reconnaissance. The team from GEER, supported by the National Science Foundation, investigated the Decatur, Tennessee earthquake. The collaboration included Dan Brown and Associates; the University of Memphis; the University of Tennessee; the University of Colorado-Boulder; the Georgia Institute of Technology; the University of California-Los Angeles; and Geosyntec Consultants.
GEER Association was formed as an outgrowth of grassroots efforts to investigate and document the geotechnical impacts of the 1989 Loma Prieta Earthquake, 1994 Northridge Earthquake, and 1995 Kobe Earthquake. Following these earthquakes, members of the geotechnical earthquake engineering community responded with ad hoc reconnaissance teams that relied on past personal and professional relationships. The National Science Foundation awarded a grant to GEER to help formalize post-disaster geotechnical engineering reconnaissance efforts.
On December 12, 2018 at 4:14am EST, a moment magnitude (Mw) 4.4 earthquake occurred approximately 12 kilometers North-Northeast of Decatur, Tennessee (TN) (Latitude: 35.612°N Longitude: 84.732°W), which is roughly 240 kilometers southeast of Nashville, TN. Fifty-two instrumentation stations detected the earthquake ground motion as far as 485 kilometers away in Memphis, TN. The closest station (23 kilometers from the epicenter) at the Tennessee Technology Center in Athens, TN recorded a peak ground acceleration (PGA) of .0119g and a peak ground velocity (PGV) of 0.34cm/s. The highest recorded PGA was 0.0215g at the Dayton, TN station which is approximately 36 km from the epicenter. As of December 18, 2018, at least 21 aftershocks followed the December 12, 2018 earthquake. On December 20, 2018, a Geotechnical Extreme Events Reconnaissance (GEER) investigator visited the area of the epicenter in search of any visible damage. The epicenter and surrounding area are located in a rural setting where the building stock is primarily widely spaced, single-story residences and, in particular, manufactured homes. The firsthand reconnaissance canvassed the accessible areas as best as possible through many of the private residences were posted with "No Trespassing" signs, which prohibited observation on private land. Overall, the GEER team reconnaissance did not encounter any firsthand evidence of earthquake-induced damage. Several prominent organizations including the Tennessee Valley Authority (TVA), the Oak Ridge National Laboratory (ORNL), the Y-12 National Security Complex and Tennessee Department of Transportation (TDOT) reported that either there was no damage to their facilities or that their operations were unaffected due to earthquake.
View the report: Geotechnical Reconnaissance of the December 12, 2018 M4.4 Decatur, Tennessee Earthquake
About the report: 2018 TENNESSEE EARTHQUAKE
Learn more about Geer: Geotechnical Extreme Events Reconnaissance
Learn more about Glenn at: https://www.geosyntec.com/people/glenn-rix
Learn more about Melissa at: https://www.linkedin.com/in/missysetz/