I have a few questions about the earthquake, maybe somebody here knows the answers.

1. The historical record. In California scientists are working to make a future forecasts based on 150 years of historical information. China has about 2000-3000 years worth. This area of China specifically, is it possible to look over the past 2000 years to see how many and how often quakes have hit? It would be interesting to see how common this particular quake is. (ACTUALLY same question goes for Japan or any siesmically active areas in the middle of long established societies)

2. People felt it strongly up to 900 miles away. If a 7.9 quake hit the Salton Sea section of San Andreas, would people feel it all the way in Albequrque or El Paso? Or up to Oregon? Or is the soil different in China that this happened?