Earthquake · reviewed by a seismologist
M 2.7md
2km SSW of Alamo, CA
- When
- Magnitude
- M 2.7 (md)
- Depth
- 9.7 km below the surface
- Felt
- 506 reports · strongest reported intensity IV
- Nearest
- Contra Costa County, 13 km NE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1139 days ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 506 people have reported feeling it to USGS.
How big was it?
This earthquake released about 350 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 43,000× the energy of this one
- Magna, Utah 2020 M 5.7 31,000× the energy of this one
- Around the size people start to feel M 3.0 2.7× the energy of this one
- This earthquake M 2.7 about 350 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 37.8308, -122.0477. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Contra Costa County, CA | 13 km (8 mi) | SW of here | earthquakes near Contra Costa County |
| Alameda County, CA | 24 km (15 mi) | NNW of here | earthquakes near Alameda County |
| Solano County, CA | 49 km (31 mi) | S of here | earthquakes near Solano County |
| San Mateo County, CA | 54 km (34 mi) | NNE of here | earthquakes near San Mateo County |
| Marin County, CA | 66 km (41 mi) | ESE of here | earthquakes near Marin County |
| San Joaquin County, CA | 69 km (43 mi) | W of here | earthquakes near San Joaquin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
57 earthquakes have been recorded within 50 km since this one.
- 2.1 1km N of El Cerrito, CA
- 2.2 13km NE of Milpitas, CA
- 1.9 1km SSE of Crockett, CA
- 1.5 0km W of Kensington, CA
- 2.0 3km SE of American Canyon, CA
- 1.6 2km SSE of Pacheco, CA
- 1.6 2km S of Oakland, CA
- 1.6 2km S of San Ramon, CA
- 1.6 12km ENE of Milpitas, CA
- 1.6 12km ENE of Milpitas, CA
- 1.6 12km ENE of Milpitas, CA
- 1.9 3km E of Hayward, CA
- 2.0 2km ESE of Berkeley, CA
- 1.5 6km WNW of Sunol, CA
- 2.2 4km WSW of Colma, 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 4.5 on 2019-10-15 — it released about 420 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.