Posts Tagged ‘richtor’
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 |
Tags: 20, 2011, 20th, 241, 242, 3.8, 3.9, 4, 4.0, 4.2, afternoon, aftershock, Aftershocks, bay area, Berkeley, california, campus, clark kerr, colleg, did you feel it, dorm, earthquake, east, east bay, EPICENTER, epicentre, fault, feel, felt, filed, hayward, magnitude, map, Oakland, october, p-m, quake, residence, richter, richtor, san andreas, San Francisco, scale, softball, thursday, uc berkeley, university of california, usgs
Posted in events | 6 Comments »
Thursday, January 7th, 2010
It felt like a quick initial jolt followed up by three seconds of shaking to those of us in San Francisco. See what people thought about the latest rumblings of our San Andreas Fault over at SFist.com.
The updated report from the USGS indicates a 4.2 near the city of Milpitas.
Right here, “A” marks the spot:

A light earthquake occurred at 10:09:35 AM (PST) on Thursday, January 7, 2010.
The magnitude 4.2 event occurred 10 km (6 miles) ENE of Milpitas, CA.
The hypocentral depth is 9 km ( 6 miles).
| Magnitude |
4.2 – local magnitude (ML) |
| Time |
Thursday, January 7, 2010 at 10:09:35 AM (PST)
Thursday, January 7, 2010 at 18:09:35 (UTC) |
| Distance from |
Milpitas, CA – 10 km (6 miles) ENE (62 degrees)
Alum Rock, CA – 12 km (8 miles) NNE (12 degrees)
Sunol, CA – 16 km (10 miles) SSE (150 degrees)
San Jose City Hall, CA – 17 km (11 miles) NNE (29 degrees)
|
| Coordinates |
37 deg. 28.6 min. N (37.477N), 121 deg. 47.8 min. W (121.797W) |
| Depth |
9 km (5.6 miles) |
| Location Quality |
Excellent |
| Location Quality Parameters |
Nst= 89, Nph= 89, Dmin=3 km, Rmss=0.08 sec, Erho=0.1 km, Erzz=0.4 km, Gp=36 degrees |
| Event ID# |
nc71336726 |
| Additional Information |
map with fault names
Google Earth KML (Requires Google Earth.)
ShakeMap shaking intensity maps
NCSS First Motion Mechanism 1 |
As per usual, t’was the Northern Calaveras (it means “skulls”) branch of the San Andreas. Alum Rock, will you ever win?

Tags: (BART), 10:09, 10:10, 2010, 4.1, 4.2 magnitude, 7th, Alameda, alum rock, am, bay area, Bay Area Rapid Transit, branch, calaveras, california, Contra Costa, county, earthquake, Earthquake Hazards Program, january, light, magnitude, marin, milpitas, moderate, morning, Muni, resevoir, richter, richtor, san andreas, san francsico, san jose, San Mateo, Santa Clara, scale, sunol, TRACKS, transit, tunnel, U.S. Geological Survey, usgs
Posted in Uncategorized | 8 Comments »