Earthquake · reviewed by a seismologist
M 1.5md
7km NE of Alum Rock, CA
- When
- Magnitude
- M 1.5 (md)
- Depth
- 3.1 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Clara County, 22 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3076 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 5.4 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 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 37.4073, -121.7687. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Santa Clara County, CA | 22 km (14 mi) | NNW of here | earthquakes near Santa Clara County |
| Alameda County, CA | 30 km (18 mi) | SSE of here | earthquakes near Alameda County |
| Santa Cruz County, CA | 49 km (30 mi) | NNE of here | earthquakes near Santa Cruz County |
| San Mateo County, CA | 53 km (33 mi) | E of here | earthquakes near San Mateo County |
| Contra Costa County, CA | 59 km (37 mi) | SSE of here | earthquakes near Contra Costa County |
| Stanislaus County, CA | 70 km (43 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
39 earthquakes have been recorded within 50 km since this one.
- 1.9 4km SSW of Loyola, CA
- 1.8 5km SSW of Loyola, CA
- 2.8 6km SSW of Loyola, CA
- 1.8 5km SSW of Loyola, CA
- 1.7 2km E of Danville, CA
- 2.4 2km E of Danville, CA
- 1.7 2km ESE of Danville, CA
- 2.8 2km ESE of Danville, CA
- 2.3 15km E of Seven Trees, CA
- 1.6 8km E of Alum Rock, CA
- 1.6 9km E of San Martin, CA
- 1.5 9km ENE of Milpitas, CA
- 3.0 16km E of Seven Trees, CA
- 2.0 8km ENE of Gilroy, CA
- 1.7 4km ESE of Union City, 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 7,700 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.