Earthquake · reviewed by a seismologist
M 3.4mw
8 km ENE of San Martin, California
- When
- Magnitude
- M 3.4 (mw)
- Depth
- 7.5 km below the surface
- Felt
- 271 reports · strongest reported intensity III
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Santa Clara County, 19 km NW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3175 days ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 271 people have reported feeling it to USGS.
How big was it?
This earthquake released about 2.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 80,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 3,600× the energy of this one
- Magna, Utah 2020 M 5.7 2,500× the energy of this one
- This earthquake M 3.4 about 2.1 tons of TNT
- Around the size people start to feel M 3.0 this one released 4.4× more
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 37.1203, -121.5235. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Santa Clara County, CA | 19 km (12 mi) | SE of here | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 45 km (28 mi) | ENE of here | earthquakes near Santa Cruz County |
| Stanislaus County, CA | 67 km (42 mi) | SW of here | earthquakes near Stanislaus County |
| Alameda County, CA | 68 km (42 mi) | SSE of here | earthquakes near Alameda County |
| San Benito County, CA | 69 km (43 mi) | NW of here | earthquakes near San Benito County |
| Merced County, CA | 71 km (44 mi) | W of here | earthquakes near Merced 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.
- 1.9 10km E of Alum Rock, CA
- 3.9 8km ENE of Alum Rock, CA
- 3.1 9km ENE of San Martin, CA
- 2.2 9km SSW of Tres Pinos, CA
- 1.8 9km ENE of San Martin, CA
- 1.9 9km ENE of San Martin, CA
- 3.3 9km ENE of San Martin, CA
- 2.0 7km SSE of Gilroy, CA
- 1.6 7km WSW of Gilroy, CA
- 3.0 11km SW of Ridgemark, CA
- 1.7 6km SSW of Ridgemark, CA
- 2.0 15km E of Seven Trees, CA
- 1.8 10km E of Alum Rock, CA
- 1.6 9km SSW of Tres Pinos, CA
- 1.7 3km E of Aromas, 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 9.8 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.