High-resolution mapping based on Unmanned Aerial Vehicle (UAV) to capture the paleoseismic offsets along the Altyn-Tagh fault, China
Abstract
Low resolution of topographic data often increases error in the estimation of seismic offsets along the strike-slip faults. This is particularly true when offsets created by the ancient earthquake occurred several hundreds of years ago. Due to erosion, the piercing markers for reconstruction of the offset may be unclear on the image. In addition, it is difficult to evaluate the relative chronology of the incised features for precise matching the offset markers without 3D topography. Therefore, a high resolution data is needed to reduce the error of the offsets. The recent explosion in millimeter to centimeter resolution topographic data obtained by Unmanned Aerial Vehicle (UAV) raises the possibility of mapping offset geomorphology along active faults with higher accuracy. Here, for the first time, we tested this new method to acquire high-resolution imagery and generate topographic data along the Altyn Tagh fault, which is located in a high altitude remote area and shows preserved ancient earthquake surface ruptures. A digital elevation model (DEM) of 0.08 m resolution and an orthophoto with a resolution of 0.2 m were generated from these images by the Agisoft PhotoScan software. We identified piercing markers and reconstructed offsets based on both orthoimage and topography. The results show that based on the high-resolution UAV data, we could accurately measure the ancient seismic offsets. Therefore, the UAV mapping provides great potential for investigations on seismic hazards assessments. In addition, we determined a co-seismic offset of 7 ± 0.5 m of the latest earthquake event, and 14m, 28 m, 60 m, 90 m cumulative offsets which may be due a series of paleo-erthquakes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMNH11B1723G
- Keywords:
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- 9805 Instruments useful in three or more fields;
- GENERAL OR MISCELLANEOUSDE: 9820 Techniques applicable in three or more fields;
- GENERAL OR MISCELLANEOUSDE: 4333 Disaster risk analysis and assessment;
- NATURAL HAZARDSDE: 4339 Disaster mitigation;
- NATURAL HAZARDS