Ignition of subterranean methane: unveiling a new geohazard in Japan following 2024 Noto Peninsula Earthquake

Abstract The M7.6 earthquake struck the Noto Peninsula in central Japan on January 1, 2024. Approximately 50 min later, a large-scale fire broke out in Kawai-machi, Wajima City. Despite investigations by the Fire and Disaster Management Agency (FDMA), the ignition source and process remained undetermined. This study hypothesizes that the fire may have originated from underground in the absence of a surface ignition source. The investigation included a review of historical records of earthquake-induced fires, analysis of media footage, geological literature reviews, field surveys, and chemical analyses of gases in groundwater. The findings suggest that methane gas released from underground reservoirs likely played a key role in this unprecedented fire.