Seismologist deems Calif. quakes 'curious'

YORBA LINDA, Calif., April 13 (UPI) -- U.S. Geological Survey seismologist Susan Hough says the recent small earthquakes in California's China Hills are "curious" incidents.

Hough said the series of minor earthquakes, which included three small tremors during the weekend, are outside the norm in relation to seismological activity, The Orange County (Calif.) Register said Sunday.

"It's curious in the sense that it's one of those sequences that doesn't fit neatly into a well recognized mold," Hough said. "If it's a swarm then it certainly isn't a typical one -- not that we understand what a swarm is, or why they happen!"

"Offhand, I can't recall another sequence quite like it, although it's possible they've happened before and we've just never noticed because they haven't been close to populated areas."

The Register said a 1.5-magnitude earthquake occurred Sunday in the China Hills region in the wake of Saturday's tremors that featured magnitudes of 2.8, 2.7 and 1.4.