Is the deformation rate of the Longmenshan fault zone really small? Insight from seismic data at the two-decade time scale

摘要

Local earthquake catalogues complete down to M_L 2.5 are used to calculate the cumulative Benioff strain along the central- and north-Longmenshan fault zone which accommodated the May 12, 2008, Wenchuan M_S 8.0 earthquake. The nearby Xianshuihe, Anninghe, and Zemuhe fault zone are used for comparison. The data revealed that at the two-decade time scale which is different from geological process and GPS measurement, considering both horizontal and vertical deformation, and comparing with the neighboring active fault systems, the Longmenshan fault zone seems not as 'quiet' as traditionally assessed, providing a lesson for future seismic hazard analysis.