There appears to be little for insurers and reinsurers to worry about in the wake of the largest earthquake to strike the San Francisco Bay area for almost 20 years.

The moderate earthquake struck a rural area about nine miles northeast of San Jose, on Tuesday, at 8 p.m. local time.

According to the United States Geological Survey it had a magnitude of 5.6 and briefly halted train services and prompted residents in downtown San Jose, Silicon Valley's biggest city, to flee apartments.

Local and state authorities responded to a number of calls concerning gas leaks, disrupted phone service, and broken water pipes, but little other quake-related damage was reported.

"Though Tuesday's earthquake, which occurred at a depth of 5.7 miles, posed little threat to property, it was felt over a wide region, including San Francisco, 50 miles north of San Jose, Stockton, 50 miles to the east, and Redwood Shores in Redwood City, 25 miles to San Jose's north," said Jayanta Guin, senior vice president of research and modeling at boston-based AIR Worldwide.

"This span of Northern California is home to eight major faults. The epicentre of Tuesday's event was close to the intersection of the northern and central segments of the Calaveras Fault, which extends for 76 miles, splaying from the San Andreas Fault near Hollister and terminating, at its northern end, near Danville.

"It is one of the most geologically active and complex faults in the San Francisco Bay area. Its central segment, in particular, is characterised by abundant microseismicity, reflected by a high rate of seismic creep."

According to the USGS, the central Calaveras Fault is capable of producing earthquakes no larger than magnitude 6.2.