Surface Deformation Associated with the 22 August 1902 Mw 7.7 Atushi Earthquake in the Southwestern Tian Shan, Revealed from Multiple Remote Sensing Data

Abstract

The 22 August 1902 Mw 7.7 Atushi earthquake is the most disastrous seismic event in the southwestern Tian Shan. However, the spatial distribution of surface rupture zones as well as the geometric feature of surface deformation remain unclear, and the seismogenic fault is still controversial. Based on geologic and geomorphic interpretations of multiple remote sensing imaging data, high-resolution DEM data derived from UAV imaging complemented by field investigations, we mapped two sub-parallel NEE-trending surface rupture zones with a total length of 108 km. In addition, ~60 km and ~48 km surface rupture zones are distributed along the pre-existing Atushi fault (ATF) and the Keketamu fault (KTF), respectively. The surface deformations are mainly characterized as bedrock scarp, hanging wall collapse scarp, pressure ridge, and thrust-related fold scarps along the two south-dipping thrust faults, which are defined as the seismogenic structure of the 1902 Mw 7.7 Atushi earthquake. Thus, we proposed the cascading-rupture model to explain the multiple rupture zones generated by the 1902 Mw 7.7 Atushi earthquake. Moreover, the multiple advanced remote sensing mapping techniques can provide a promising approach to recover the geometric and geomorphic features of the surface deformation caused by large seismic events in the arid and semi-arid regions.

Sentinel-1 Interferometry and UAV Aerial Survey for Mapping Coseismic Ruptures: Mts. Sibillini vs. Mt. Etna Volcano

“…The ground survey of coseismic ruptures on large regions is long, time-consuming hard work, in all the mophostructural contexts including steep rugged mountain slopes, vast desert areas and complex urbanized regions [2]. In recent years, the aid of spaceborne Lidar and photogrammetry, with sub-meter scale sampling, has allowed the surveying of large areas affected by coseismic ruptures [21]. On the other hand, the availability accomplishment of an airborne survey needs to be planned over time, sometimes months or years after the earthquake, with consequent wear and loss of data.…”

“…The available technology allows for the easy acquisition of spatial data, using different methodological approaches and data sources at variable scales [20]. The availability of a precise location with the Global Navigation Satellite System (GNSS), and the accessibility of high resolution multitemporal satellite images, digital aerial photogrammetry, terrestrial and aerial Lidar techniques, allows the production of precise and high resolution topographic maps which make it is easier to report geological structures and landforms in detail [21].…”