Correlation of earthquake occurrence among major fault zones in the eastern margin of the Tibetan Plateau through Big Data Analysis

<p>Regional earthquake correlation represents a fundamental yet open issue in seismicity and geodynamics. This study addresses the synchronicity of earthquake occurrences through statistical correlations among the active fault zones along the eastern margin of the Qinghai-Tibetan Plateau by means of a big data analysis approach. Utilizing the latest earthquake catalog (1970-August 2024), in association with the 17 major fault zones, we introduce an innovative method for catalog segmentation and apply Z-tests, Pearson correlation coefficients, and correlation network analysis to examine fault seismic activity relationships. The results reveal a seismic spatiotemporal migration pattern characterized by reduced seismicity near prominent earthquake epicenters, with subsequent large earthquakes occurring on non-adjacent faults and increased activity around epicenters. Through correlation networks, we identify three major seismic activity clusters: the eastern boundary of the Bayan Har Block, the eastern boundary of the Sichuan-Yunnan Rhombic Block, and the Sanjiang Lateral Collision Zone, aligning with traditional tectonic block divisions, validating the seismic activity similarity clustering method and filling the statistical gap in conventional classifications. Surprisingly, some faults belong to neither the same seismic belt nor the same geological block, exhibiting a regional-scale remote triggering pattern of earthquake nucleation or structural evolution under the concept of a complex fault system. Additionally, we show that while parallel or conjugate fault orientations do not necessarily lead to synchronized seismic activity, faults exhibiting synchronized activity typically have parallel or conjugate geometries. The revealed seismic activity patterns contribute to improving earthquake forecasting and offer a fresh perspective on regional tectonic evolution and seismic dynamics.</p>