Last night's temblor came from a rupture 4 miles (6 km) underground and struck at 7 12 p.m. local time (23:12 UTC), the USGS reported.
The last big earthquake on the southern San Andreas fault, a magnitude 7.9 temblor, ruptured from Monterey County through Los Angeles County in 1857.
The scientist, Brian Baptie, seismic project team leader with the British Geological Survey, said data from the two quakes near Blackpool — one of magnitude 2.3 on April 1, the other of magnitude 1.5 on May 27 — suggested the temblors arose from the same source.
The death toll from the temblor was estimated to have exceeded 140,000.
At 2 28 a.m. on Nov. 8 the temblor shook the span from its perch.
Anecdotal reports from those nearby — for example, our contacts in banking, housing construction, and housing-related businesses — suggest significant damage from the temblor".
The Capitol took a noticeable jolt from the temblor and was closed until about 5 p.m., when staffs were allowed to re-enter.
Though they cautioned that they were working with less than two days' data from Wednesday's earthquake here, scientists are already saying that they are finding evidence of much less shaking and damage than they might have expected, even from a temblor so deep.
For one thing, it was the largest temblor ever measured far from the boundary of a tectonic plate, researchers report online today in Science.
Staffers at the Altoona Mirror evacuated their building after it shook for about 10 seconds from the temblor.
