Three‐Dimensional Density Distribution and Seismic Activity along the Guxiang‐Tongmai Segment of the Jiali fault, Tibet

Abstract

AbstractThe Guxiang‐Tongmai segment of the Jiali fault is situated northeast of the Namche Barwa Syntaxis. It is one of the most active strike‐slip faults near the Namche Barwa Syntaxis and plays a pivotal role in the examination of seismic activity within the eastern Himalayan Syntaxis. In this dissertation, we meticulously processed the data acquired in the research region, yielding a 1:200,000 gravity dataset covering an area 1500 km2. Using wavelet transform multiscale decomposition, scratch analysis techniques, and 3D gravity inversion methods, we determined gravity anomalies, fault distributions, and density structures across various scales. Through the integration of our new gravity data with other geophysical and geological information, our findings demonstrate substantial variations in the overall crustal density within the region, with the fault distribution closely linked to these density fluctuations. Disparities in stratigraphic density are importment causes of variations in the capacity of geological formations to endure regional tectonic stress. Earthquakes are predominantly concentrated within the density transition zone and are primarily situated in regions of elevated density. The hanging wall stress within the Guxiang‐Tongmai segment of the Jiali fault exhibits a notable concentration, marked by pronounced anisotropy, and is positioned within the density differential zone, which is prone to earthquakes.