Earthquake · reviewed by a seismologist
M 2.1md
15km E of Seven Trees, CA
- When
- Magnitude
- M 2.1 (md)
- Depth
- 1.6 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Clara County, 8 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2963 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 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
- Magna, Utah 2020 M 5.7 270,000× the energy of this one
- Around the size people start to feel M 3.0 24× the energy of this one
- This earthquake M 2.1 about 40 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 37.2873, -121.6703. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Santa Clara County, CA | 8 km (5 mi) | NNE of here | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 43 km (27 mi) | NE of here | earthquakes near Santa Cruz County |
| Alameda County, CA | 45 km (28 mi) | SSE of here | earthquakes near Alameda County |
| San Mateo County, CA | 64 km (40 mi) | ESE of here | earthquakes near San Mateo County |
| Stanislaus County, CA | 66 km (41 mi) | WSW of here | earthquakes near Stanislaus County |
| Contra Costa County, CA | 75 km (46 mi) | SSE of here | earthquakes near Contra Costa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
51 earthquakes have been recorded within 50 km since this one.
- 1.7 3km S of Loyola, CA
- 1.6 2km ESE of Pleasanton, CA
- 2.0 11km SSE of Portola Valley, CA
- 1.8 10km E of Alum Rock, CA
- 2.8 6km SW of Gilroy, CA
- 1.6 8km NE of Alum Rock, CA
- 1.7 3km S of Loyola, CA
- 1.8 12km ESE of Gilroy, CA
- 1.9 12km NNW of Hollister, CA
- 1.6 7km SW of Gilroy, CA
- 1.7 4km SSW of Los Altos Hills, CA
- 2.1 15km E of Seven Trees, CA
- 1.5 16km SSE of Livermore, CA
- 1.6 10km NE of Gilroy, CA
- 1.9 11km SSE of Portola Valley, 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 4.1 on 2017-10-10 — it released about 1,000 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.