Statistical Features of Seismicity Associated with Large Earthquakes on the Chinese Continent between 2008 and 2019 Based on Newly Detected Catalogs

Abstract

The Chinese continent is seismically active and is an important region for analyzing statistical behaviors of large intraplate earthquake sequences. A systematic and detailed record of large earthquake sequences provides the basis for such analysis in a tectonically complex region. In this study, using a graphic processing units-accelerated matched filter technique, we detected up to five times more events than standard earthquake catalogs to generate newly detected catalogs for 32 Ms≥6.0 earthquakes on the Chinese continent from October 2008 to December 2019. The statistical analysis of the newly detected high-resolution catalogs showed that strike-slip mainshocks have higher potential to have anomalous foreshock sequences but are followed by fewer aftershocks than those with other faulting styles. We also provided an example for the 2014 Yingjiang, Yunnan, earthquake sequence, in which the b-value shows a reduction for foreshock sequences and is followed by a recovery in the aftershock period. Our detected catalogs can be used to further study statistical behaviors of earthquake sequences, which is essential for understanding earthquake interaction and improving seismic hazard assessment on the Chinese continent and around the world.

Migrating Foreshocks Driven by a Slow Slip Event Before the 2021 MW 6.1 Yangbi, China Earthquake

“…For earthquakes along continental faults with slower deformation rates than in subduction zones or ice streams, recent analyses suggest a wide range of the mainshock nucleation process (Li et al, 2024;Wetzler et al, 2023). For example, analysis on single-station waveforms reveals nearly repeating foreshocks during the last 44 min before the 1999 M W 7.6 Izmit earthquake along the North Anatolian Fault in Türkiye (Bouchon et al, 2011), supporting the pre-slip model with accelerated fault creep right before the mainshock.…”