QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Gilroy, CA

No earthquake was likely felt in Gilroy in the 24 hours to 7:38 pm PST (03:38 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 2.9 earthquake was recorded 10 km (6 mi) east-southeast of Gilroy, CA, at 8:06 am PDT on 15 April 2017 (15:06 UTC), 3.3 km deep. 15 people have reported feeling it to USGS.

USGS: 10 km ESE of Gilroy, California

12 km (7 mi) ESE of Gilroy, CA · 48 km (30 mi) SE of San Jose, CA

8:06 am PDT, Apr 15, 2017 · · 3.3 km deep · released about 590 lb of TNT

10 km30 km60 km120 km N Santa Clara County 35 kmSanta Cruz County 49 kmSan Benito County 52 kmMerced County 70 kmStanislaus County 77 kmMonterey County 82 kmAlameda County 85 kmSan Mateo County 95 kmSan Joaquin County 108 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
8:06 am PDT on 15 April 2017 ()
Where
10 km (6 mi) east-southeast of Gilroy, CA · earthquakes near Gilroy
Magnitude
M 2.9 (md)
Depth
3.3 km below the surface
Felt
15 reports · strongest reported intensity III
Nearest
Santa Clara County, 35 km NW
Nearest mapped fault
Calaveras 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 3495 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 30 km (19 mi) from the epicentre. In Gilroy, 10 km away, the estimate is intensity III (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 10 km, intensity III · Hollister 14 km, intensity III · Morgan Hill 25 km, intensity II · Watsonville 27 km, intensity II · Prunedale 29 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 590 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 26,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 590 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 4.2 on 2016-07-19 — about 110 times the energy of this one.

Before 2016, the USGS record lists 27 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 38 km W of this epicentre
  2. 6.5 Near Morgan Hill, California · 22 km NW of this epicentre
  3. 6.2 Near San Jose, California · 47 km NW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 42 km NNW of this epicentre
  5. 6.1 Near San Jose, California · 40 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 36.9708, -121.4590. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 35 km (21 mi) NW earthquakes near Santa Clara County
Santa Cruz County, CA 49 km (30 mi) W earthquakes near Santa Cruz County
San Benito County, CA 52 km (32 mi) SE earthquakes near San Benito County
Merced County, CA 70 km (43 mi) ENE earthquakes near Merced County
Stanislaus County, CA 77 km (48 mi) NNE earthquakes near Stanislaus County
Monterey County, CA 82 km (51 mi) S earthquakes near Monterey County

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

Aftershocks so far

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

  1. 1.6 25 km SE of Tres Pinos, California
  2. 1.5 25 km SE of Tres Pinos, California
  3. 1.6 1 km SE of Lexington Hills, California
  4. 2.0 5 km SE of Tres Pinos, California
  5. 2.5 11 km S of Tres Pinos, California
  6. 2.8 11 km S of Tres Pinos, California
  7. 2.1 9 km SSW of Tres Pinos, California
  8. 2.9 11 km S of Tres Pinos, California
  9. 2.7 6 km NE of Ridgemark, California
  10. 1.7 19 km ESE of East Foothills, California
  11. 2.7 4 km NNW of Hollister, California
  12. 1.9 4 km WNW of Hollister, California
  13. 1.9 7 km ENE of Interlaken, California
  14. 1.7 12 km S of Tres Pinos, California
  15. 1.7 12 km S of Tres Pinos, 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.