The 2008 M7.9 Wenchuan Earthquake - Result of a Water Reservoir Impoundment?

The May 12, 2008 M7.9 Wenchuan earthquake occurred along the Longmen Shan margin of the eastern Tibetan plateau in the Sichuan province of the People's Republic of China. A complex and shallow dipping reverse fault system including the Beichuan fault ruptured 250-300 km parallel to the Longmen Shan thrust belt. This region has been tectonically loaded for >10,000 years. It has low deformation rates of less than 1.0+/-1.0 mm per year resulting in no major seismic activity during the Quaternary period.

Approximately 2 years prior the nucleation of the mainshock, at least millions of tonnes of water accumulated within 15 km of the upper Min river valley near the epicenter. Here, it enters the Chengdu plain of the Sichuan basin, a stable continental region.

Now, a major question is whether this earthquake might have been triggered by these mass changes? Some scientists say “yes”. But, scientific evidence for such a statement is needed!!! Some questions need to be answered? How much water was impounded, where and when? Did resulting stress changes alter stresses deep in the Earth's crust (~19 km)? Were stress alterations significantly large enough? Where was the highest seismic energy release - close to the reservoir?