Earthquake · reviewed by a seismologist
M 1.9md
3km N of Piedmont, CA
- When
- Magnitude
- M 1.9 (md)
- Depth
- 11 km below the surface
- Felt
- 62 reports · strongest reported intensity IV
- Nearest
- Contra Costa County, 26 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2747 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 62 people have reported feeling it to USGS.
How big was it?
This earthquake released about 23 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 660,000× the energy of this one
- Magna, Utah 2020 M 5.7 470,000× the energy of this one
- Around the size people start to feel M 3.0 42× the energy of this one
- This earthquake M 1.9 about 23 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 37.8533, -122.2363. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Contra Costa County, CA | 26 km (16 mi) | WSW of here | earthquakes near Contra Costa County |
| Alameda County, CA | 37 km (23 mi) | NW of here | earthquakes near Alameda County |
| Marin County, CA | 50 km (31 mi) | ESE of here | earthquakes near Marin County |
| San Mateo County, CA | 50 km (31 mi) | NNE of here | earthquakes near San Mateo County |
| Solano County, CA | 53 km (33 mi) | SSW of here | earthquakes near Solano County |
| San Francisco County, CA | 71 km (44 mi) | ENE of here | earthquakes near San Francisco County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 1.7 1km N of East Richmond Heights, CA
- 2.0 5km N of San Leandro, CA
- 1.8 3km S of Alamo, CA
- 1.7 4km ESE of American Canyon, CA
- 3.4 2km NE of Pacheco, CA
- 1.5 2km W of Crockett, CA
- 1.9 4km NE of Vallejo, CA
- 2.0 6km WSW of Colma, CA
- 1.5 3km ESE of Rodeo, CA
- 1.5 12km E of Blackhawk, CA
- 2.6 4km ESE of Oakland, CA
- 2.9 3km ESE of Berkeley, CA
- 1.5 3km ENE of Oakland, CA
- 2.5 10km ESE of Black Point-Green Point, CA
- 1.9 10km ESE of Black Point-Green Point, 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 4,900 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.