Aerial2lidar3d: A New Point Cloud-Optical Image Matching Technique to Quantify Near-Field, Surface Co-Seismic Deformation in 3D: Application to the 1999 Mw 7.1 Hector Mine Earthquake and New Surface Offset Measurements of the 1999 Mw 7.6 Izmit earthquake

Chris W. Milliner, James F. Dolan, Robert Zinke, James Hollingsworth, Sebastien Leprince, & Francois Ayoub

Published August 14, 2016, SCEC Contribution #6760, 2016 SCEC Annual Meeting Poster #088

Measurements of co-seismic surface deformation of large magnitude earthquakes are of critical importance for the characterization of distributed deformation and understanding fault zone mechanics. Recent developments in geodetic matching techniques such as lidar differencing have proven vital in providing accurate measurements of the near-field, co-seismic deformation patterns of surface ruptures, areas where InSAR typically decorrelates and traditional field surveys lack measurement of distributed deformation. However, a major limitation to the differencing approach is that owing to the expense and recent development of lidar it’s spatial coverage is largely limited, and most legacy data is of poor quality. Here we develop a new and complementary technique to quantify the full 3D pattern of co-seismic surface deformation by matching post-event lidar data with pre-event DEMs generated from stereo-pair air photos, data that is inexpensive and ubiquitous in both space and time, thus resolving the issue of missing pre-earthquake lidar data anticipated in measuring future events. We apply this new technique to the 1999 Mw 7.1 Hector Mine earthquake, using Structure for Motion software (to build the topographic point cloud), ICP (to co-register and match the point clouds), and COSI-Corr (to quantify the horizontal motion). Using this approach we successfully produced detailed 3D deformation maps at 15 m resolution, detecting 0.2-1.35 m of vertical fault slip along a 3.5 km stretch of the Hector Mine surface rupture. In addition, we also present new fault offset measurements along the 1999 Mw 7.6 Izmit surface rupture using high resolution air photos, measured from offset tree lines, fences and roads, and comparing these to field survey measurements to assess whether they have missed distributed, ‘off-fault’ deformation. Detailed measurements of co-seismic deformation using high-resolution optical images has implications for better understanding fault segmentation and linkage, important information for PSHA models, constraints of surface slip in finite slip inversions, and reliable data to accurately constrain empirical scaling relations.

Key Words
lidar fault slip Izmit optical image correlation COSI-Corr SfM

Citation
Milliner, C. W., Dolan, J. F., Zinke, R., Hollingsworth, J., Leprince, S., & Ayoub, F. (2016, 08). Aerial2lidar3d: A New Point Cloud-Optical Image Matching Technique to Quantify Near-Field, Surface Co-Seismic Deformation in 3D: Application to the 1999 Mw 7.1 Hector Mine Earthquake and New Surface Offset Measurements of the 1999 Mw 7.6 Izmit earthquake. Poster Presentation at 2016 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Geology