Earthquake · reviewed by a seismologist
M 1.6md
4km NNW of Pacifica, CA
- When
- Magnitude
- M 1.6 (md)
- Depth
- 8.8 km below the surface
- Felt
- no reports yet
- Nearest
- San Mateo County, 29 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2650 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
How big was it?
This earthquake released about 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 8.1 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.
Where
Epicentre 37.6478, -122.5127. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| San Mateo County, CA | 29 km (18 mi) | NNW of here | earthquakes near San Mateo County |
| San Francisco County, CA | 47 km (29 mi) | E of here | earthquakes near San Francisco County |
| Marin County, CA | 49 km (31 mi) | SSE of here | earthquakes near Marin County |
| Alameda County, CA | 53 km (33 mi) | W of here | earthquakes near Alameda County |
| Contra Costa County, CA | 58 km (36 mi) | WSW of here | earthquakes near Contra Costa County |
| Santa Cruz County, CA | 84 km (52 mi) | NNW of here | earthquakes near Santa Cruz 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.
- 1.8 2km ESE of Alamo, CA
- 1.8 4km W of Dublin, CA
- 1.8 7km SSW of Muir Beach, CA
- 2.2 3km NNW of Pacifica, CA
- 1.6 6km WNW of Dublin, CA
- 1.7 2km NE of Union City, CA
- 1.8 6km WSW of Colma, CA
- 1.9 6km WSW of Colma, CA
- 1.6 6km WSW of Colma, CA
- 3.5 5km WSW of Colma, CA
- 2.3 3km NE of Orinda, CA
- 1.8 1km E of El Cerrito, CA
- 1.8 3km WNW of Lafayette, CA
- 1.8 3km NE of Orinda, CA
- 1.9 3km NE of Orinda, 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.
For this area
The largest earthquake within 50 km in our catalogue was M 4.4 on 2018-01-04 — it released about 14,000 times the energy of this one.
From the QuakeIndex catalogue, built from the USGS FDSN event service.
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.