High-Resolution Topographic Mapping of Active Faults in Southern California with Satellite Optical Imagery

William D. Barnhart, Michael J. Willis, Terryl L. Bandy, Rich Briggs, Brianna Morales, & Mark Faney

Published August 4, 2016, SCEC Contribution #6495, 2016 SCEC Annual Meeting Poster #133

Digital elevation models (DEMs) provide a core data set for many studies of active tectonics. They allow for the identification and quantification of fault offsets, modeling of localized and regional fluvial responses to vertical and lateral fault displacements, and mapping of active fault traces, among other applications. Very high spatial resolution (<5 m per pixel)DEMs greatly enhance these efforts by resolving subtle yet important variations in topography. Moreover, DEMs and LiDAR observations with spatial resolutions <5 m are increasingly used as geodetic tools to measure co-seismic deformation. However, these high-resolution data sets are commonly expensive to acquire, encompass limited ground footprints, and are difficult to re-acquire for the purposes of temporal change detection. High-resolution satellite optical imagery catalogs provide one means to overcome these limitations. Here, we present preliminary high resolution DEMs (0.3-2 m per pixel) generated from in-track stereo imagery of the WorldView satellite constellation. Our initial work spans the Ventura and San Gorgonio Special Fault Study Areas, as well as distributed faulting south of the San Jacinto and Elsinore fault zones on trend with the 2010 M 7.2 El Mayor-Cucapah rupture. DEMs were processed using the NASA Ames Stereo Pipeline software suite and Ohio State University’s Surface Extraction from TIN-Based Searchspace Minimization (SETSM) algorithm on the University of Iowa’s Neon and University of North Carolina’s KillDevil supercomputers. We also present initial quality control metrics by comparing our derived DEMs to existing topographic data sets, such as the B4 LiDAR data set. Initial comparisons of our raw DEMs to B4 LiDAR swaths indicate 1-sigma elevation uncertainties of ~1.5 m, and we expect these uncertainties to decrease after co-registering these data sets and applying various filtering algorithms. These data sets and open-source software tools provide a means to rapidly generate high-resolution DEMs of exceptional quality and spatial resolution over broad regions, allowing for frequent re-acquisition of data sets, geodetic analysis, and detailed landscape analysis.

Key Words
High-resolution DEMs, Fault Zone Mapping, Remote Sensing, Earthquake Geodesy

Citation
Barnhart, W. D., Willis, M. J., Bandy, T. L., Briggs, R., Morales, B., & Faney, M. (2016, 08). High-Resolution Topographic Mapping of Active Faults in Southern California with Satellite Optical Imagery. Poster Presentation at 2016 SCEC Annual Meeting.

Related Projects & Working Groups
Tectonic Geodesy