The San Francisco Bay Area was shaken by an earthquake of 5.6 magnitude on the Richter scale on Tuesday night.

The US Geological Survey said that the quake hit at 8:04 pm and had the epicenter was located about nine miles from San Jose. The shake was felt all the way to Sacramento and as far north as Sonoma.

No serious damages or injuries were reported. Public transportation was halted for several minutes after the quake occurred in the Bay Area and then continued with reduced speeds.

This was the largest quake to hit the San Francisco Bay area in two decades. The last one occurred in October 1989, when the Loma Prieta earthquake hit this region causing 62 deaths and $ 6 billion in damage.

Tuesday, dozens of aftershocks were reported by the US geological Survey, with magnitudes between 1.3 and 2.0. The quake came from the Calaveras Fault with the epicenter near Alum Rock, in the Diablo range foothills east of San Jose.

A USGS geophysicist, Raphael Avrue, from the agency’s offices in Golden Colorado, said that the quake was a very shallow one, at 5.7 miles underground. “It’s the kind of seismic activity we have come to expect in the San Francisco Bay Area,” he said according to the San Mateo Daily News.

Steve Walter, a seismologist at the USGS in Menlo Park, said this is one of the strongest quakes in recent history in the Alum Rock section, produced by the Calaveras Fault. No larger earthquake is expected from this fault, that usually produces quakes of 4 or 5 magnitude.

Earthquakes can be expected from the Hayward Fault, which produces severe quakes every 151 years, give or take 23 years. This is a period of alert, as the last earthquake to be generated by the fault occurred in 1868.

According to the Associated Press, if a quake was produced by this fault it would wipe out 155,000 housings units, of these, 37,000 from San Francisco alone.