Posts Tagged ‘p-m’

Magnitude 4.0 Earthquake Struck UC Berkeley at 2:41 PM, October 20th 2011 – 3.8 Aftershock at 8:16 PM

Thursday, October 20th, 2011

[Or rather, make that a 4.0 on the Richter, final answer. That was for the afternoon earthquake. This evening's aftershock at 8:16 PM was a 3.8.]

People in the West Bay could definitely feel this this one today, the one centered beneath UC Berkeley.

It felt like a succession of sharp bumps for a few seconds and then there was some generalized shaking – perhaps it all lasted about six seconds.

The Did You Feel It Map:

The initial estimate was a 4.2:

Magnitude 4.2
Date-Time
  • Thursday, October 20, 2011 at 21:41:04 UTC
  • Thursday, October 20, 2011 at 02:41:04 PM at epicenter
Location 37.864°N, 122.249°W
Depth 9.8 km (6.1 miles)
Region SAN FRANCISCO BAY AREA, CALIFORNIA
Distances
  • 2 km (2 miles) ESE (112°) from Berkeley, CA
  • 5 km (3 miles) NE (47°) from Emeryville, CA
  • 5 km (3 miles) NNW (341°) from Piedmont, CA
  • 8 km (5 miles) NNW (346°) from Oakland, CA
Location Uncertainty horizontal +/- 0.2 km (0.1 miles); depth +/- 0.4 km (0.2 miles)
Parameters Nph= 90, Dmin=2 km, Rmss=0.18 sec, Gp= 22°,
M-type=local magnitude (ML), Version=3
Source
Event ID nc71667366