Use of small unmanned aerial vehicle (sUAV)-acquired topography for identifying and characterizing active normal faults along the Seerteng Shan, North China

摘要

High-resolution topographic datasets are being increasingly applied in studies of active tectonics for precise quantification of lateral and vertical offsets of landforms. Digital elevation models (DEM) acquired by airborne light detection and ranging (LiDAR) have also been used for morphological analysis of tectonic scarps to infer the seismic-slip history of active faults. However. the high cost of conducting LiDAR studies limits its widespread application. In contrast. the potential applicability of the low-cost and portable small unmanned aerial vehicles (sUAV) combined with structure-from-motion (SIM) techniques to investigate morphological features of fault-generated scarps and their paleoseismic implications has not been fully explored. Here, based on sUAV-acquired DEMs and field observations, we present a case study of the morphological features of fault scarps along the Seertengshan Piedmont Fault (SPF), a major boundary fault of the Hetao Graben, North China, and discuss their paleoseismic implications. The results demonstrate that low-angle (25 degrees) scarp slopes along the SPF suggestive of a long period of erosion are consistent with the results of paleoseismological studies (i.e., the most recent surface-faulting event occurred 2000 years ago). The observed 1.8-2.5-m-high fault scarps with single slope sections probably represent the most recent incremental displacements associated with surface-rupturing earthquake(s). Topographic data acquired by sUAV are suitable for quantitative morphological analyses of fault-generated scarps in actively deforming regions and can contribute to assessments of seismic hazard. (C) 2020 Elsevier B.V. All rights reserved.