<p>Title: In situ Measurement of Dynamic Soil Nonlinearity (NEES-2005-0090)</p> <p><strong>Year Of Curation: </strong>2008</p> <p><strong>Description: </strong>The objectives of the project are to develop a technique for measuring in situ nonlinear sediment response to strong shaking. Our approach brings together experimental protocols developed by physicists in the laboratory to study dynamic non-linear phenomena in a variety of materials, the new controlled-source mobile vibrator trucks developed by NEES members, and state-of-the-art seismic array recording and processing tools. We suggest that new perspectives (e.g. models rooted in the physics of the response of many types of materials) will lead to new understanding. Additionally, the methods we employ are completely non-invasive, with all observations made at the surface. (</p> <p><strong>Award: </strong>USGS 05CRSA0629</p> <p><strong>PIs &amp; CoPIs: </strong>Joan Gomberg</p> <p><strong>Dates: </strong>January 01, 2005 - September 30, 2005</p> <p><strong>Organizations: </strong>,United States Geological Survey (USGS),,University of Texas at Austin, TX, United States</p> <p><strong>Facilities: </strong>University of Texas at Austin, TX, United States</p> <p><strong>Sponsor: </strong>USGS - 05CRSA0629</p> <p><strong>Keywords: </strong>In-Situ Non-Linearity,Sediment Non-Linearity,Strong Ground Motion,Vibroseis Truck,T-Rex</p> <p><strong>Publications </strong></p> <nb:citations></nb:citations>

<p><strong>Title</strong>: Seismic Reflection Transect Across the New Madrid Seismic Zone: Imaging Sediment Structure (NEES-2006-0167)</p> <p><b>Year Of Curation: </b>--</p> <p><b>Description: </b>The overall goal of this project is to provide high-resolution images of the sediment structure in the Mississippi embayment, which will in turn provide key constraints on earthquake hazard assessments in this large, at risk area. Funding is provided jointly by both the USGS and the NSF.This is motivated by the need to better understand the spatial and long-term temporal patterns of deformation in the New Madrid seismic zone, so that earthquake recurrence models that underlie hazard assessments may be put on sounder scientific footing. We suggest that this can be done while also addressing the need to better constrain how seismic waves propagate in the tremendously thick sediments of the Mississippi embayment, another key aspect of earthquake hazard assessments in the region.The project consists of two complementary experiments: 1. Using the Thumper, obtain an approximately 15-km long, high-resolution compressional-wave reflection image of the subsurface geology, including faults and folds, in the 30- to 1000-meter depth range. 2. Obtain shear-wave images of the upper ~300 m at several sites within the embayment, using a variety of surface-wave analyses.</p> <p><b>Award: </b>--</p> <p><b>PIs &amp; CoPIs: </b>Joan Gomberg, Robert Williams</p> <p><b>Dates: </b>May 1, 2006</p> <p><b>Organizations: </b>U.S. Geological Survey</p> <p><b>Facilities: </b>University of Texas at Austin, Austin, TX, United States</p> <p><b>Sponsor: </b>NSF - 0530709 (</p> <p><b>Keywords: </b>seismic reflection, New Madrid, sediment structure</p> <p><b>Publications:&nbsp;</b>R. Williams, W. Stephenson, T. Pratt, J.K. Odum, &quot;Post - Eocene Deformation Observed in Seismic - Reflection Profiles Across the Southwestern Blytheville Ar ch and Crowleys Ridge, Arkansas&quot;</p> <nb:citations></nb:citations>