Descr: The New Madrid Seismic Zone (NMSZ) poses the greatest seismic risk in mid-America yet its tectonic origin and lack of appreciable current deformation remain a major enigma. With modest support from the College of Arts and Science at Miami University and the Research Board and the National Center for Supercomputing Applications (NCSA) at the University of Illinois, we will be undertaking a pilot study of the NMSZ with an array of about ten broadband seismographs, consisting of Guralp 3T sensors and Reftek 130 data acquisition systems. The deployment will begin in July of 2005 and can serve as a pilot study for future EarthScope/USArray projects in and around the New Madrid region. We aim to obtain new observations on deep-seated lithospheric structures in order to complement other results from seismicity, crustal imaging, geodesy, geopotential and geological mapping. To connect with short-term UW-Madison deployments over a decade ago (employing mid-period sensors), we plan t! o reoccupy some previous sites in the NMSZ. Furthermore, we will also focus on the northward extension of the NMSZ into the southern Illinois Basin, where 1) some of the largest earthquakes in mid-America occurred over the past 100 years, 2) an apparent aseismic zone exists south of the Cottage Grove fault system, and 3) a sub-crustal reflector has been identified from deep seismic reflection profiles. The broadband nature of our data will further constrain lithospheric structures by utilizing frequency-dependent properties of seismic reflections/conversions and anisotropy.
