Seismologists say that the USGS has recorded 28 quakes from 1.1 to 3.9 over the past seven days. Dr. David Schwartz of the United States Geological Survey says they were so widely felt because they were so close to the Earth's surface. He has also said that the public has nothing to fear and that this kind of activity "is normal."
The 1989 Loma Prieta quake was the biggest and latest to hit the Bay Area at 6.9. Dr. Schwartz says the Bay Area is due for another big quake, but it is hard to tell when that will be without more data.
Always be sure to have a plan in case of an Earthquake! See a documentary of the Loma Prieta quake below.