According to Wiki's Richtor Scale the 8.8 quake was equal to a 15.8gigaton explosion. How does a 15.8 Gt explosion measure up to all the World's nuclear stockpiles detonating at once in one spot? Stronger or weaker? Then what about the fact that this quake lasted several minutes. Would each individual tremor of the 8.8 be considered one 15.8 gigaton blast? When I tried to understand 15.8g as a large pile of TNT, I came up with 43,287 Empire State buildings made out of TNT lined up side by side. It's difficult to imagine a pile of TNT that large detonating. 15.8 gigatons is such a large number for an explosive force. At least with numbers that big it is not so difficult to imagine an 8.8 changing the rotation of the Earth which quakes this large do.