Cause and mechanism of highly compressed and dense methane gas mass for Wenchuan Earthquake and associated rock-avalanches and surface co-seismic ruptures

Abstract

This paper presents and shows that Wenchuan Earthquake of May 12, 2008 was caused by the rapid migration and expansion of a large amount of highly pressurized and dense methane gas mass in crustal rock masses. The dense gas mass was trapped in deep crustal rock masses. Because of increase in its pressure and mass, the dense gas mass suddenly ruptured the crustal rocks at deep Longmenshan faults with high compressions. A part of the dense gas mass escaped the trap and rapidly migrated from deep crustal rock to shallow crustal rocks along the faults, contacts and beddings and expanded the crustal rock masses. The expanding power of the dense gas that migrated into some isolated hard rock slopes caused the rock avalanche-rock debris flows at mountains. The expanding power of the dense gas that migrated into some isolated soil river beds and slopes caused the co-seismic ruptures at ground surfaces.