On the correlation of earthquake occurrence among major fault zones in the eastern margin of the Tibetan Plateau by Big Data Analysis

TL;DR

This study analyzes the correlation of earthquake occurrences among fault zones in the eastern Tibetan Plateau using big data, revealing strong coupling relationships and potential remote triggering patterns that enhance understanding of regional seismicity and hazard assessment.

Contribution

It introduces a novel big data analysis approach to identify correlations and remote triggering among fault zones, providing new insights into regional seismicity and fault interactions.

Findings

Six fault zone pairs show high correlation (>0.6) across multiple indicators.

Some non-adjacent fault zones exhibit strong internal affinity, indicating remote interactions.

Identification of a regional-scale remote triggering pattern among fault zones.

Abstract

The subsequent series of responses to big events may exhibit a synchronicity of event number, frequency and energy release in different fault zones. This synchronicity is a reliable source for probing non-intuitive geological structures, assessing regional seismicity hazard map and even predicting the next big events. The synchronicity of main faults in the eastern margin of the Qinghai-Tibetan Plateau is still unknown to us. We propose to examine the correlation of earthquake occurrence among different fault zones to indicate this synchronicity, and to obtain a preliminary understanding of geodynamics processes and the unrecognized characteristics of deep evolution in the eastern margin of the Qinghai-Tibetan Plateau. We estimate temporal changes of completeness level, frequency seismicity, and intensity seismicity, referring respectively to Mc, Z, and E values, of 21 main fault zones, using a seismic catalogue from 1970 to 2015. Our results reveal that six fault zone pairs of fault zones exhibit relative high correlation (>0.6) by all three indicators, while four fault zone pairs are non-adjacent with close internal affinity offsetting the limit of spatial distance, such as the pair of Rongjing-mabian fault and Minjiang-huya fault. Most strikingly, some fault zone pairs showing typical high correlation (>0.8) of seismicity frequency or seismicity intensity, the faults surprisingly belong to neither the same seismic belt nor the same geological block, exhibiting a regional scale remote triggering pattern of earthquakes or structures. An embryonic pattern to predict the next possible events will also be presented. This correlation analysis discovers a previously unrecognized strong coupling relationship among main faults with high earthquake risk in the eastern margin of the Qinghai-Tibetan Plateau.