Active tectonics of the onshore Hengchun Fault using UAS DTM combined with ALOS PS-InSAR time series (Southern Taiwan)

Abstract

Abstract. Geometry, characterization and quantification of active faults are major concern in Taiwan, especially following the major Chichi earthquake of September 21 st , 1999. Among the targets that still remain poorly known in terms of active 15 tectonics, are the Hengchun and Kenting faults (Southern Taiwan). From the geodynamic point of view, the latter affects the outcropping top of the Manila accretionary prism of the Manila subduction zone that runs from Luzon (N. Philippines) to Taiwan. In order to settle the location, characterization and quantification of the Hengchun fault, we needed to up-date the Chinese Petroleum Corporation (CPC, 1993) and Central Geological Survey (Sung, 1991) existing geological maps using GIS mapping and photo-interpretation of both UAS's acquisition : 1). the very high precision (<50 cm) and resolution (<10 20 cm) Digital Terrain Model, and the 2). the georeferenced aerial photograph mosaic of the studied area. Moreover, the superimposition of the resulting structural sketch map with the new PSI interferometric data acquired through the SAR ALOS 1 images, validated by GPS data, helps to give motions, characterisation and quantification of the displacements along the LOS during the monitoring time-series (2007)(2008)(2009)(2010)(2011). We therefore focus herein on the geometry, the characterization and the quantification of the Hengchun Fault which is an active left-lateral transpressive fault. Finally, as the 25Hengchun ridge face one of the last major earthquake of Taiwan (Dec. 26th 2006, depth: 44 Km, M L =7.0), it is needed to better constrain the active Hengchun Peninsula tectonics in order to prevent major destructions in the near future.

Multi-Temporal High-Resolution Landslide Monitoring Based on Uas Photogrammetry and Uas Lidar Geoinformation

“…UAV based remote sensing applications have been reported by researchers in various disciplines, especially in morphotectonic study, e.g. Deffontaines et al (2017Deffontaines et al ( , 2018Deffontaines et al ( , 2019, Chang et al (2018), etc. In order to monitoring the landslides, high-resolution images are acquired since 2015.…”