QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Gilroy, CA

No earthquake was likely felt in Gilroy in the 24 hours to 10:49 pm PST (06:49 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 1.7 earthquake was recorded 5 km (3 mi) south-southwest of Gilroy, CA, at 9:26 pm PDT on 13 August 2017 (04:26 UTC), 5.3 km deep.

USGS: 5 km SSW of Gilroy, California

5 km (3 mi) S of Gilroy, CA · 42 km (26 mi) SSE of San Jose, CA

9:26 pm PDT, Aug 13, 2017 · · 5.3 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Santa Clara County 30 kmSanta Cruz County 37 kmSan Benito County 59 kmMerced County 81 kmAlameda County 81 kmMonterey County 84 kmStanislaus County 85 kmSan Mateo County 86 kmContra Costa County 111 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
9:26 pm PDT on 13 August 2017 ()
Where
5 km (3 mi) south-southwest of Gilroy, CA · earthquakes near Gilroy
Magnitude
M 1.7 (md)
Depth
5.3 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 30 km NNW
Nearest mapped fault
Sargent fault, 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 3369 days ago

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 11 km (7 mi) from the epicentre. In Gilroy, 5 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 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 6,200 times the energy of this one.

Before 2016, the USGS record lists 31 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 27 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 17 km NNW of this epicentre
  3. 6.2 Near San Jose, California · 42 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 · 32 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 36.9617, -121.5912. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 30 km (19 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 37 km (23 mi) W earthquakes near Santa Cruz County
San Benito County, CA 59 km (37 mi) SE earthquakes near San Benito County
Merced County, CA 81 km (51 mi) ENE earthquakes near Merced County
Alameda County, CA 81 km (51 mi) NNW earthquakes near Alameda County
Monterey County, CA 84 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

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

  1. 1.7 8 km E of Chualar, California
  2. 3.2 1 km SSW of San Juan Bautista, California
  3. 1.9 3 km ESE of Tres Pinos, California
  4. 1.5 15 km E of Seven Trees, California
  5. 1.8 5 km ENE of Aromas, California
  6. 2.3 5 km SW of Gilroy, California
  7. 1.7 18 km SW of Gustine, California
  8. 1.7 5 km NNE of Tres Pinos, California
  9. 1.5 19 km SW of Gustine, California
  10. 1.6 Northern California
  11. 1.6 19 km SW of Gustine, California
  12. 2.4 5 km ESE of Interlaken, California
  13. 1.5 6 km ESE of Prunedale, California
  14. 2.3 11 km S of Tres Pinos, California
  15. 1.9 Northern 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.