Upgrading and reconstruction of the comprehensive lightning protection system at Jiaxiang Seismic Monitoring Station

Most of the geophysical observation instruments at the Jiaxiang Seismic Monitoring Station are installed in caves. These instruments are digital and networked precision monitoring devices. As the station is located in a lightning-prone area, it has suffered multiple failures caused by lightning strikes over a long period, resulting in interruptions to observation data. A comprehensive upgrade and renovation of the lightning protection system was conducted on the station’s office building and observation caves in 2022. The project included lightning protection measures for signal lines, the upgrade and renovation of the outdoor grounding grid, equipotential bonding systems and down conductors, and the installation of surge diverters. The aim was to improve the station’s overall lightning protection capability, ensure the stable operation of the station’s instruments, and guarantee the continuity and reliability of the station’s geophysical observation data. The post-renovation results have confirmed that the station’s comprehensive lightning protection capability has been well enhanced, providing protection against most induced lightning and direct lightning strikes at the station. However, they cannot provide effective protection against a small number of sudden and severe direct lightning strikes. Therefore, it is important to strengthen routine inspection and testing of the station’s power supply and lightning protection equipment.