The quake hit at 8:41 AM local time, less than a mile from the surface. A second smaller quake hit five minutes later. "The earthquake was the largest in the Geysers area in the past 30 years. This magnitude 5.0 earthquake is only marginally larger than previous earthquakes at the Geysers," USGS Research geophysicist J. Ole Kaven wrote to SFGATE. "This earthquake occurred on the western margin of where previous seismicity has been located." ... "The historical record of earthquakes in this area suggests that earthquakes as large as today's are likely to be near the upper magnitude limit," wrote...