Earthquake · reviewed by a seismologist
M 2.1md
3km SW of Monte Sereno, CA
- When
- Magnitude
- M 2.1 (md)
- Depth
- 8.5 km below the surface
- Felt
- 24 reports · strongest reported intensity III
- Nearest
- Santa Cruz County, 23 km S
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2763 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 24 people have reported feeling it to USGS.
How big was it?
This earthquake released about 41 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 5.8 370,000× the energy of this one
- Magna, Utah 2020 M 5.7 260,000× the energy of this one
- Around the size people start to feel M 3.0 23× the energy of this one
- This earthquake M 2.1 about 41 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 37.2188, -122.0173. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Santa Cruz County, CA | 23 km (14 mi) | N of here | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 29 km (18 mi) | W of here | earthquakes near Santa Clara County |
| San Mateo County, CA | 38 km (24 mi) | SE of here | earthquakes near San Mateo County |
| Alameda County, CA | 49 km (30 mi) | S of here | earthquakes near Alameda County |
| Contra Costa County, CA | 78 km (49 mi) | S of here | earthquakes near Contra Costa County |
| Stanislaus County, CA | 97 km (61 mi) | WSW of here | earthquakes near Stanislaus County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
49 earthquakes have been recorded within 50 km since this one.
- 2.4 9km ENE of San Martin, CA
- 2.3 13km NNE of Morgan Hill, CA
- 1.8 10km ENE of Milpitas, CA
- 1.6 8km NE of Alum Rock, CA
- 1.6 4km SE of Portola Valley, CA
- 1.7 10km E of Alum Rock, CA
- 1.6 6km SSW of Gilroy, CA
- 2.2 6km E of Fremont, CA
- 1.8 8km E of Interlaken, CA
- 2.1 14km ENE of Seven Trees, CA
- 2.6 12km ESE of Alum Rock, CA
- 2.6 12km ESE of Alum Rock, CA
- 1.6 12km ESE of Alum Rock, CA
- 2.1 8km E of Alum Rock, CA
- 2.3 2km E of Bonny Doon, 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.