Four notable earthquakes have rocked the Chino Hills, just north of YorbaLinda, since yesterday. The recent quakes have greatly accelerated a swarm thatlast week was called 'curious' and 'unusual' by one of Southern California'stop seismologists.The largest of the quakes was felt throughout much of Orange County.
All four quakes rumbled in a region that's had a 'swarm' of quakes sinceearly March. The quakes are also close to the area of the Chino Hills--theso-called Yorba Linda trend--that produced a 5.4 quake last July. The region isclose to the Chino and Elsinore fault zones.
Susan Hough, head of the USGS's Pasadena office, called the earthquakeswarms curious earlier this month.
one of those sequences that doesnmold,we understand what a swarm is, or why they happen!Story by Senior Meteorologist Henry Margusity
