QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6mw

Earthquake near Gilroy, CA

No earthquake was likely felt in Gilroy in the 24 hours to 4:27 pm PST (00:27 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 3.6 earthquake was recorded 5 km (3 mi) south of Gilroy, CA, at 6:58 am PST on 26 February 2017 (14:58 UTC), 4.5 km deep. 664 people have reported feeling it to USGS.

USGS: 5 km S of Gilroy, California

5 km (3 mi) S of Gilroy, CA · 43 km (27 mi) SSE of San Jose, CA

6:58 am PST, Feb 26, 2017 · · 4.5 km deep · released about 3.8 tons of TNT

10 km30 km60 km120 km N Santa Clara County 31 kmSanta Cruz County 39 kmSan Benito County 58 kmMerced County 80 kmAlameda County 82 kmMonterey County 83 kmStanislaus County 84 kmSan Mateo County 87 kmSan Joaquin County 112 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
6:58 am PST on 26 February 2017 ()
Where
5 km (3 mi) south of Gilroy, CA · earthquakes near Gilroy
Magnitude
M 3.6 (mw)
Depth
4.5 km below the surface
Felt
664 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Santa Clara County, 31 km NNW
Nearest mapped fault
Sargent fault, 3 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 1786 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 69 km (43 mi) from the epicentre. In Gilroy, 5 km away, the estimate is intensity IV (light). 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 5 km, intensity IV · Watsonville 17 km, intensity III · Hollister 19 km, intensity III · Morgan Hill 20 km, intensity III · Prunedale 22 km, intensity III · Salinas 32 km, intensity II · Capitola 34 km, intensity II · Live Oak 36 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 45,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,400× the energy of this one
  4. This earthquake M 3.6 about 3.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 7.9× 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.2 on 2016-07-19 — about 8.5 times the energy of this one.

Before 2016, the USGS record lists 30 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 28 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 18 km NNW of this epicentre
  3. 6.2 Near San Jose, California · 43 km NNW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 40 km NNW of this epicentre
  5. 6.1 Near San Jose, California · 33 km NW 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 36.9590, -121.5757. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 31 km (19 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 39 km (24 mi) W earthquakes near Santa Cruz County
San Benito County, CA 58 km (36 mi) SE earthquakes near San Benito County
Merced County, CA 80 km (50 mi) ENE earthquakes near Merced County
Alameda County, CA 82 km (51 mi) NNW earthquakes near Alameda County
Monterey County, CA 83 km (52 mi) SSE earthquakes near Monterey County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

48 earthquakes have been recorded within 50 km since this one.

  1. 2.1 3 km ESE of Aromas, California
  2. 1.6 4 km ESE of Aromas, California
  3. 3.2 5 km ESE of Aromas, California
  4. 4.0 2 km ESE of Aromas, California
  5. 1.8 14 km E of Seven Trees, California
  6. 1.6 3 km WSW of San Juan Bautista, California
  7. 2.6 3 km WSW of San Juan Bautista, California
  8. 1.9 5 km SSW of Gilroy, California
  9. 1.5 16km NW of Pinnacles, CA
  10. 1.6 16 km SE of Tres Pinos, California
  11. 2.0 17 km SSE of Tres Pinos, California
  12. 1.9 17 km SSE of Tres Pinos, California
  13. 2.7 4 km S of San Juan Bautista, California
  14. 1.9 13 km S of Tres Pinos, California
  15. 1.7 6 km ESE of Prunedale, California

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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.