2008 saw notable increase in moderate Southern California earthquakes by Jia-Rui Chong

Do you think the ground feels a little shakier these days? It's not your imagination. Last year saw a significant increase in the number of temblors of magnitude 3.0 or greater in Southern California and the northern portion of Baja California, according to data from Caltech and the U.S. Geological Survey. (Snip) What experts don't know is whether the quake cluster is a harbinger of bigger quakes to come.