Earthquake · reviewed by a seismologist
M 1.5md
4km ENE of Boulder Creek, CA
- When
- Magnitude
- M 1.5 (md)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Cruz County, 16 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3005 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 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
- Around the size people start to feel M 3.0 170× the energy of this one
- This earthquake M 1.5 about 5.7 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 37.1478, -122.0803. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Santa Cruz County, CA | 16 km (10 mi) | NNW of here | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 36 km (22 mi) | WSW of here | earthquakes near Santa Clara County |
| San Mateo County, CA | 39 km (24 mi) | SE of here | earthquakes near San Mateo County |
| Alameda County, CA | 57 km (36 mi) | SSW of here | earthquakes near Alameda County |
| Contra Costa County, CA | 87 km (54 mi) | S of here | earthquakes near Contra Costa County |
| Stanislaus County, CA | 106 km (66 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
43 earthquakes have been recorded within 50 km since this one.
- 1.6 11km S of Portola Valley, CA
- 1.7 3km S of Loyola, CA
- 1.6 7km SW of Gilroy, CA
- 1.7 4km SSW of Los Altos Hills, CA
- 1.9 18km WNW of Bonny Doon, CA
- 2.2 18km WNW of Bonny Doon, CA
- 2.1 15km E of Seven Trees, CA
- 1.9 11km SSE of Portola Valley, CA
- 2.7 8km ENE of Alum Rock, CA
- 2.2 18km WNW of Bonny Doon, CA
- 1.5 3km S of Loyola, CA
- 2.5 9km E of Alum Rock, CA
- 1.6 18km WNW of Bonny Doon, CA
- 2.8 15km ENE of Alum Rock, CA
- 1.8 7km ENE of Morgan Hill, 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 7,200 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.