Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Gilroy, CA
No earthquake was likely felt in Gilroy in the 24 hours to 10:54 pm PST (06:54 UTC). The last one was M 2.5, 9 km (6 mi) E, at 7:27 pm PST on 1 November 2026, estimated intensity II (weak) in town; 2 felt reports to USGS. Every earthquake near Gilroy
This page: a magnitude 1.5 earthquake was recorded 6 km (4 mi) southwest of Gilroy, CA, at 11:01 am PDT on 4 September 2021 (18:01 UTC), 3.0 km deep.
USGS: 6km SW of Gilroy, CA
in Gilroy, CA · 41 km (25 mi) SSE of San Jose, CA
- When
- 11:01 am PDT on 4 September 2021 ()
- Where
- 6 km (4 mi) southwest of Gilroy, CA · earthquakes near Gilroy
- Magnitude
- M 1.5 (md)
- Depth
- 3.0 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Clara County, 29 km NNW
- Nearest mapped fault
- Sargent fault, under 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1888 days ago
Earthquake alerts for Gilroy, CA
Get a notification in this browser when USGS records an earthquake near Gilroy, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Gilroy, 6 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Gilroy 6 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 6.2 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 2,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
- Around the size people start to feel M 3.0 150× the energy of this one
- This earthquake M 1.5 about 6.2 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.
For this area
The largest earthquake within 50 km since 2016 was M 4.7 on 2019-10-15 — about 57,000 times the energy of this one.
Before 2016, the USGS record lists 31 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 25 km WNW of this epicentre
- 6.5 Near Morgan Hill, California · 16 km N of this epicentre
- 6.2 Near San Jose, California · 40 km NNW of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 38 km N of this epicentre
- 6.1 Near San Jose, California · 31 km NNW of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 36.9682, -121.6127. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Clara County, CA | 29 km (18 mi) | NNW | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 35 km (22 mi) | W | earthquakes near Santa Cruz County |
| San Benito County, CA | 61 km (38 mi) | SE | earthquakes near San Benito County |
| Alameda County, CA | 80 km (50 mi) | NNW | earthquakes near Alameda County |
| Merced County, CA | 83 km (51 mi) | ENE | earthquakes near Merced County |
| San Mateo County, CA | 84 km (52 mi) | NW | earthquakes near San Mateo County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
38 earthquakes have been recorded within 50 km since this one.
- 2.5 12km S of Tres Pinos, CA
- 1.6 12km S of Tres Pinos, CA
- 3.7 13km S of Tres Pinos, CA
- 2.7 12km S of Tres Pinos, CA
- 1.8 3km E of Aromas, CA
- 2.9 4km SSW of San Juan Bautista, CA
- 1.6 15km NW of Pinnacles, CA
- 2.0 12km S of Tres Pinos, CA
- 2.0 11km SSW of Ridgemark, CA
- 1.7 14km SSE of Tres Pinos, CA
- 1.6 3km W of Fruitdale, CA
- 2.1 6km S of San Juan Bautista, CA
- 1.9 13km S of Tres Pinos, CA
- 2.2 13km S of Tres Pinos, CA
- 1.5 17km SSE of Tres Pinos, 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.
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.