HR: 0800h
AN: T51D-0765    [Abstracts]
TI: FOCUS: Fault Observatory for the Central United States
AU: Wolf, L W
EM: wolflor@auburn.edu
AF: Auburn University, Dept. of Geology and Geography 210 Petrie Hall, Auburn, AL 36849, United States
AU: * Langston, C A
EM: clangstn@memphis.edu
AF: CERI, University of Memphis, 3876 Central Ave., Ste. 1, Memphis, TN 38152-3050, United States
AU: Powell, C A
EM: capowell@memphis.edu
AF: CERI, University of Memphis, 3876 Central Ave., Ste. 1, Memphis, TN 38152-3050, United States
AU: Cramer, C
EM: ccramer@memphis.edu
AF: CERI, University of Memphis, 3876 Central Ave., Ste. 1, Memphis, TN 38152-3050, United States
AU: Johnston, A
EM: ajohnstn@memphis.edu
AF: CERI, University of Memphis, 3876 Central Ave., Ste. 1, Memphis, TN 38152-3050, United States
AU: Hill, A
EM: aahill@memphis.edu
AF: University of Memphis, Dept. of Earth Sciences, Memphis, TN 38152, United States
AB: The mid-continent has a long, complex history of crustal modification and tectonism. Precambrian basement rocks record intense deformation from rifting and convergence that precedes accumulation of a thick sequence of Phanerozoic and recent sediments that constitute the present-day Mississippi Embayment. Despite its location far from the active North American plate margins, the New Madrid seismic zone of central U.S. exhibits a diffuse yet persistent pattern of seismicity, indicating that the region continues to be tectonically active. What causes this intraplate seismicity? How does the intraplate lithosphere support local, regional and plate-wide forces that maintain earthquake productivity in this supposedly stable tectonic setting? These long-standing scientific questions are the motivation behind the proposed establishment of a borehole geo-observatory in the New Madrid seismic zone. FOCUS (Fault Observatory for the Central U.S.) would allow an unprecedented look into the deep sediments and underlying rocks of the Embayment. The proposed drill hole would fill a critical need for better information on the geophysical, mechanical, petrological, and hydrological properties of the brittle crust and overlying sediments that would help to refine models of earthquake generation, wave propagation, and seismic hazard. Measurements of strains and strain transients, episodic tremor, seismic wave velocities, wave attenuation and amplification, heat flow, non-linear sediment response, fluid pressures, crustal permeabilities, fluid chemistry, and rock strength are just some of the target data sets needed. The ultimate goal of FOCUS is to drill a 5-6 km deep scientific hole into the Precambrian basement and into the New Madrid seismic zone. The scientific goal of FOCUS is a better understanding of why earthquakes occur in intraplate settings and a better definition of seismic hazard to benefit the public safety. Short-term objectives include the preparation of an International Continental Drilling Program (ICDP) preproposal, initiation of site selection activities, communication with the international scientific community via scientific meetings and presentations, and development of funding sources and proposals targeted at key agencies. Intermediate-term objectives include developing an ICDP drilling workshop proposal, investigating holes of opportunity and scientific characterization of alternative drilling sites, establishing an intermediate depth observation hole into the Paleozoic bedrock (~1 km), and preparing for an observatory dedication (not completion) on the 200th anniversary of the 1811- 1812 earthquakes. FOCUS has initially organized into a steering committee and 5 subcommittees for Geophysics and Monitoring, Drilling/Holes of Opportunity, Geology/Tectonics, Geotechnical, and Community Partners/Outreach and Education.
UR: http://www.ceri.memphis.edu
DE: 7205 Continental crust (1219)
DE: 7209 Earthquake dynamics (1242)
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7215 Earthquake source observations (1240)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting