A 10 year investigation of the gas cause of Wenchuan earthquake

Abstract

This paper presents the findings of the author’s 10-year investigation on the gas cause of Wenchuan Eearthquake. They include many natural phenomena that happened before, during and after the earthquake. The phenomena include land subsidence, earthquake sounding, high in-situ stress, co-seismic ruptures, landslides, tsunami in reservoir water, sky color changes, air temperature, rainfall, pre-shocks and aftershocks, and gas fields in west Sichuan Basin. All of these observed phenomena can be logically, consistently and quantitatively explained and interpreted with the gas cause hypothesis of tectonic earthquakes. The hypothesis assumes that a huge amount of highly compressed natural (methane) gas mass was gradually accumulated and trapped in some large apertures (and/or gaps or caves) along the deep faults of Longmanshan. The extremely high values of the compressive tectonic stresses on both sides of the main fault completely sealed, trapped and compressed the gas mass in the deep apertures along the faults. However, the ever increasing of the trapped gas mass and pressure suddenly ruptured the deep locked zones. Consequently, a small part of the trapped gas mass suddenly and rapidly escaped the traps. Its volume and pressure were estimated about 1 km3 and 300 MPa, respectively. It migrated in the fault zones with a speed of 2.8 km/s for about 110 seconds, which caused the devastating Wenchuan earthquake, seismic waves and the other associated phenomena.