Collaborative Research: Towards an Understanding of the Collective Behavior of Regional Fault Networks: The Marlborough Fault System, New Zealand (James F. Dolan, PI, University of Southern California). This project was a collaborative effort between PI Dolan (USC) and co-I Ed Rhodes (UCLA) and New Zealand collaborators Russ Van Dissen and Rob Langridge of GNS Science. The survey area consists of a total of 254 km of fault-parallel, predominantly ~1.2-km-wide swaths along parts of the four main right-lateral strike-slip faults that comprise the Marlborough Fault System, in the northwestern portion of New Zealand's South Island. The five fault segments surveyed include sections of the eastern and western parts of the Clarence fault, the central part of the Awatere fault, the central part of the Wairau fault, and part of the eastern (Conway) segment of the Hope fault. These lidar data facilitated detailed analysis of fault offsets along the four main MFS faults, as well as mapping of small displacements that have occurred in recent earthquakes on Marlborough faults in unprecedented detail, the geomorphic development and evolution of fluvial terraces crossing these faults, and the progressive geomorphic manifestation of off-fault deformation with increasing fault displacement. The data were analyzed by the PIs, our New Zealand collaborators, and three graduate students at USC (Robert Zinke, Alexandra Hatem, and Jessica Grenader), and one graduate student at UCLA (Chris McGuire [supervised by Co-I Ed Rhodes]); their results will form major parts of their graduate theses. The lidar data were collected by U.S. National Center for Airborne Laser Mapping (NCALM) personnel using an aircraft and flight personnel subcontracted from New Zealand Aerial Mapping. The data were collected with a combination of NCALM's Optech GEMINI sensor (operated at a laser pulse frequency of 125 kHz in multi-pulse mode, at a nominal height above ground of 1400 m) and NZAM's Optech 3100A sensor (operated at a laser pulse frequency of 70-100 kHz at various heights depending on terrain). Shot density is ≥ 12 shots/m2
. The lidar data were utilized in our studies of the incremental slip-rate record of the four main Marlborough faults. The lidar data also provided a means of mapping small displacements that have occurred in recent earthquakes on Marlborough faults in unprecedented detail, the sedimentological development and geomorphic evolution of fluvial terraces crossing these faults, and the progressive geomorphic manifestation of off-fault deformation with increasing fault displacement (see Zinke et al., 2015 Geology for a discussion of this latter topic [doi:10.1130/G37065.1]).
Publications associated with this dataset can be found at NCALM's Data Tracking Center