The Japan earthquake caused significantly more shaking than the San Francisco quake. The Japan earthquake had a magnitude of 9.0, while the San Francisco quake had a magnitude of 7.9. This means that the Japan earthquake released about 32 times more energy than the San Francisco quake. The Japan earthquake also lasted for about 6 minutes, while the San Francisco quake only lasted for about 15 seconds. This means that the Japan earthquake caused much more shaking than the San Francisco quake.
