回複：回複：我一直在想雅安地震是天災還是人禍呢？是不是三峽大壩誘發的四川地震？

Earthquakes will definitely repeat along the border of the Tibetan plateau. This is nature.

But how much damage an earthquake make to human life and property depends heavily on the strength of civil structures like buildings, bridges. If people lack the necessary resources to build strong structures, or they don't know how strong a structure should be, they will have trouble sooner or later.

Japan and western United States (California) are all in seismical zone. The death toll in these well developed areas is much different from earthquakes events registered in areas like Iran and China.

Take Wenchuan earthquake as an example. It is found that a lot of buildings did not have any steel in the concrete or the steel is not enough to resist the natural forces. The Huaxian event in 1556 killed nearly one million people. The killer was not earthquake itself but the collapse of the houses and caves people lived in, and the plague after the quake. On the contrary, the Da Yan Ta and Xiao Yan Ta built in Tang dynasty in Xi'an survived that terrible event.