Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Pacifica, CA
Yes: an earthquake was likely felt in Pacifica in the last 24 hours. M 1.6, 4 km (2 mi) NNW of Pacifica, at 12:47 am PST on 13 November 2026 (08:47 UTC); the estimated shaking in Pacifica was intensity II (weak). Every earthquake near Pacifica
This page: a magnitude 1.7 earthquake was recorded in Pacifica, CA, at 11:52 am PDT on 27 March 2017 (18:52 UTC), 8.1 km deep.
USGS: 1 km N of Pacifica, California
18 km (11 mi) SSW of San Francisco, CA · 8 km (5 mi) SSW of Daly City, CA
- When
- 11:52 am PDT on 27 March 2017 ()
- Where
- in Pacifica, CA · earthquakes near Pacifica
- Magnitude
- M 1.7 (md)
- Depth
- 8.1 km below the surface
- Felt
- no reports yet
- Nearest
- San Mateo County, 26 km SSE
- Nearest mapped fault
- San Andreas fault, 2 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3518 days ago
Earthquake alerts for Pacifica, CA
Get a notification in this browser when USGS records an earthquake near Pacifica, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Pacifica in town, intensity II · San Bruno 6 km, intensity II · South San Francisco 7 km, intensity II · Daly City 9 km, intensity II · Millbrae 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 95× the energy of this one
- This earthquake M 1.7 about 10 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 7.9 The 1906 San Francisco, California Earthquake · 15 km NNW of this epicentre
- 5.3 The 1957 San Francisco, California Earthquake · 4 km N of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 37.6287, -122.4835. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Mateo County, CA | 26 km (16 mi) | SSE | earthquakes near San Mateo County |
| San Francisco County, CA | 50 km (31 mi) | WNW | earthquakes near San Francisco County |
| Alameda County, CA | 50 km (31 mi) | E | earthquakes near Alameda County |
| Marin County, CA | 52 km (33 mi) | NNW | earthquakes near Marin County |
| Contra Costa County, CA | 57 km (35 mi) | NE | earthquakes near Contra Costa County |
| Santa Cruz County, CA | 80 km (50 mi) | SSE | earthquakes near Santa Cruz County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
42 earthquakes have been recorded within 50 km since this one.
- 1.6 4 km SW of Danville, California
- 2.1 2 km SSW of San Ramon, California
- 2.2 1 km SSW of San Ramon, California
- 2.7 7 km S of Muir Beach, California
- 1.8 0 km NNW of Ladera, California
- 1.6 1 km N of Ladera, California
- 2.0 1 km W of Danville, California
- 1.5 2 km E of Berkeley, California
- 2.2 Northern California
- 1.7 2 km S of Loyola, California
- 1.8 10 km WNW of Daly City, California
- 1.5 1 km W of Los Altos Hills, California
- 1.8 4 km ENE of La Honda, California
- 1.7 3 km WSW of Loyola, California
- 1.5 2 km S of Loyola, California
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.