Tectonic Deformation Analysis with ALOS-Based Digital Elevation Models in the Longshou Shan Mountains (NW China)

GeoHazards, vol. 6, pp. 74

Abstract

The Longshou Shan area is located on the northeastern margin of the Tibetan Plateau in northwest China. The study area is located where the sinistral Altyn Tagh and Haiyuan Faults overlap and the Qilian Shan thrust fault systems in the northeastern Kunlun–Qaidam Block converge. This region experiences frequent seismic events, including large-magnitude earthquakes, which are significant indicators of ongoing tectonic deformation and stress accumulation in the Earth’s crust. The seismicity of Longshou Shan is not only a consequence of its tectonic setting but also a key factor in understanding the seismic hazard posed to the surrounding areas. The tectonic activity within the Longshou Shan region of NW China is a focus of our geomorphological research due to its significance in understanding the complex interactions between tectonic forces and surface processes. Situated on the northeastern edge of the Tibetan Plateau and along the eastward trace of the Altyn Tagh Fault, Longshou Shan is crucial for investigating the plateau’s northward expansion. This study leverages ALOS-based digital elevation models (DEMs) and geomorphic indices to evaluate the tectonic activity in the area, employing various indices such as mountain front sinuosity, valley floor width-to-height ratio, hypsometric curves, asymmetry factors, basin shape indices, and channel steepness index to provide a comprehensive tectonomorphological analysis. Our results indicate intense tectonic activity on both sides of Longshou Shan, making it a highly hazardous seismic area. We also highlight the importance of thrust faults and related crustal shortening in the formation and expansion of the plateau.

Authors 2

1. Xianghe Ji corresponding Aachen Institute of Neotectonics and Natural Hazards

   RWTH Aachen University

   Affiliation as printed

   Institute of Neotectonics and Natural Hazards, RWTH Aachen University, Lochner Str. 4-20, 52064 Aachen, Germany

2. Klaus R. Reicherter Aachen Institute of Neotectonics and Natural Hazards

   RWTH Aachen University

   Affiliation as printed

   Institute of Neotectonics and Natural Hazards, RWTH Aachen University, Lochner Str. 4-20, 52064 Aachen, Germany