NEW YORK, Oct. 10 (Xinhua) -- The ground beneath U.S. Southern California has been particularly unsteady as of late, with the region experiencing more moderate-sized earthquakes this year than it has in decades, reported the Los Angeles Times on Thursday.
"What precisely is fueling the sequence of shakers is not entirely clear, and officials warn that prior seismic activity does not necessarily mean more powerful temblors are imminent. But the series of modest shakers have many wondering what is going on," said the report.
"Earthquakes pop off around the state, and it's a little bit like popcorn that they hit -- sometimes they bunch up for reasons that we don't understand," Susan Hough, seismologist for the U.S. Geological Survey, was quoted as saying.
By the count of seismologist Lucy Jones, a Caltech research associate, Southern California has felt 15 independent seismic sequences this year, with at least one magnitude 4 or higher earthquake. That's the highest annual total in the last 65 years, surpassing the 13 seen in 1988.
