According to early data provided by the US Geological Service, the quake had its epicenter 13 kilometers under Claremont Avenue, just near the Claremont Hotel. Some earthquakes can be more than 350 miles deep in countries such as Fiji, according to USGS duty seismologist Robert Sanders.
He also said there were no reports of any damage or injuries.
At a press conference, USGS officials said there was a small probability that this quake was a fore shock and will be followed by a big natural disaster: "Looking historically. about 5% of the time earthquakes are followed by larger earthquakes", said USGS quake Science Center Deputy Director Keith Knudson.
Drysdale said that depending on the magnitude of a quake in the Bay Area, Sacramentans could feel it despite having no known fault lines in the area. Near San Francisco International Airport, several jolts could be felt. "Through geologic excavations across the Hayward fault we've learned that there are earthquakes on at least the southern part of the Hayward fault every 140, 150, 160 years", said Keith Knudsen, U.S. Geological Survey. "If there isn't a large natural disaster in the next couple of the days the odds go down". It's been 150 years since the last rupture. It killed 30 people, caused widespread destruction and was one of the most destructive in California history. The last big natural disaster occurred in 1868 so we are about at the 150-year anniversary ...
The quake is said to be associated with the Hayward fault, which aligns underneath the eastern side of the Bay area - from Hayward through Berkeley.