Earthquake · reviewed by a seismologist
M 3.5mw
Earthquake near Colma, CA
No earthquake was likely felt in Colma in the 24 hours to 11:32 pm PST (07:32 UTC). The last one was M 2.7, 6 km (4 mi) S, at 5:17 pm PDT on 28 October 2026, estimated intensity III (weak) in town; 526 felt reports to USGS. Every earthquake near Colma
This page: a magnitude 3.5 earthquake was recorded 5 km (3 mi) west-southwest of Colma, CA, at 8:41 am PDT on 5 October 2019 (15:41 UTC), 7.5 km deep. 8,788 people have reported feeling it to USGS.
USGS: 5km WSW of Colma, CA
16 km (10 mi) SSW of San Francisco, CA · 6 km (4 mi) SW of Daly City, CA
- When
- 8:41 am PDT on 5 October 2019 ()
- Where
- 5 km (3 mi) west-southwest of Colma, CA · earthquakes near Colma
- Magnitude
- M 3.5 (mw)
- Depth
- 7.5 km below the surface
- Felt
- 8,788 reports · strongest reported intensity IV
- Measured shaking
- intensity VI (ShakeMap)
- Nearest
- San Mateo County, 30 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 604 days ago
Earthquake alerts for Colma, CA
Get a notification in this browser when USGS records an earthquake near Colma, 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 65 km (40 mi) from the epicentre. In Colma, 5 km away, the estimate is intensity III (weak). 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 6 km, intensity III · Daly City 7 km, intensity III · South San Francisco 9 km, intensity III · San Bruno 10 km, intensity III · Millbrae 13 km, intensity III · Bayview-Hunters Point 14 km, intensity III · San Francisco 15 km, intensity III · Burlingame 16 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 3.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 55,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 2,500× the energy of this one
- Magna, Utah 2020 M 5.7 1,700× the energy of this one
- This earthquake M 3.5 about 3.1 tons of TNT
- Around the size people start to feel M 3.0 this one released 6.5× more
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
The largest earthquake within 50 km since 2016 was M 4.4 on 2018-01-04 — about 18 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 7.9 The 1906 San Francisco, California Earthquake · 11 km NNW of this epicentre
- 5.3 The 1957 San Francisco, California Earthquake · 3 km ENE 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 37.6598, -122.5145. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Mateo County, CA | 30 km (19 mi) | SSE | earthquakes near San Mateo County |
| San Francisco County, CA | 46 km (29 mi) | W | earthquakes near San Francisco County |
| Marin County, CA | 48 km (30 mi) | NNW | earthquakes near Marin County |
| Alameda County, CA | 53 km (33 mi) | E | earthquakes near Alameda County |
| Contra Costa County, CA | 57 km (36 mi) | ENE | earthquakes near Contra Costa County |
| Solano County, CA | 84 km (52 mi) | NE | earthquakes near Solano County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
31 earthquakes have been recorded within 50 km since this one.
- 1.7 4km N of Lafayette, CA
- 1.8 2km SE of Pacifica, CA
- 1.9 5km NNW of San Leandro, CA
- 1.8 14km S of Bolinas, CA
- 1.9 5km NE of Fairview, CA
- 1.6 5km NE of Fairview, CA
- 1.9 5km W of Dublin, CA
- 2.6 3km NW of Castro Valley, CA
- 2.2 2km WNW of Orinda, CA
- 2.1 2km NE of San Leandro, CA
- 1.6 1km SSE of Palo Alto, CA
- 1.6 2km SSE of San Ramon, CA
- 2.3 2km ENE of San Leandro, CA
- 1.7 3km WSW of San Francisco Zoo, CA
- 2.1 1km ENE of El Cerrito, CA
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.