Different Seismic Network Data for Medium-Sized Earthquake Rupture Process Fast Inversion: An Application to the 2023 Mw 5.5 Pingyuan, Shandong, China Earthquake

The Shandong Seismic Network is a key component of the China Earthquake Networks Center and one of the most advanced regional seismic monitoring systems in the country. It comprises four complementary observational subnetworks: (1) a traditional broadband seismic network consisting of 124 stations installed on bedrock or in deep boreholes; (2) an earthquake early warning (EEW) strong-motion network with 238 strong-motion sensors deployed on bedrock or shallow soil; (3) an EEW MEMS (micro-electro-mechanical systems) network comprising approximately 1,230 low-cost sensors mounted on building floors or walls; and (4) a seismic array of 77 broadband seismometers installed in shallow boreholes on stable ground. Together, these four subnetworks operate a total of 1,669 instruments, providing multi-scale observational data that are critical for detailed characterization of source rupture processes during moderate-to-strong earthquakes. In this study, we analyze the M5.5 Pingyuan earthquake that struck Shandong Province on August 6, 2023 (Beijing Time, UTC+8) using data from this integrated network. Our results show that: the high-density MEMS network is sufficient for rapid post-event inversion of the rupture process, yet its inversion accuracy is somewhat limited; the strong-motion network enables stable and efficient rapid finite-fault inversion; and multi-source data fusion yields the most reliable post-earthquake source rupture model. These capabilities support quasi-real-time (within 30 minutes of the origin time), rapid, and refined imaging of earthquake rupture processes, offering critical guidance for emergency response and optimization of regional seismic networks.