QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Greenfield, CA

No earthquake was likely felt in Greenfield in the 24 hours to 6:52 am PST (14:52 UTC). The last one was M 3.0, 38 km (23 mi) N, at 2:58 pm PDT on 22 October 2026, estimated intensity II (weak) in town. Every earthquake near Greenfield

This page: a magnitude 2.9 earthquake was recorded 48 km (30 mi) east-northeast of Greenfield, CA, at 10:48 am PDT on 2 July 2019 (17:48 UTC), 8.6 km deep. 6 people have reported feeling it to USGS.

USGS: 13km NW of New Idria, CA

10:48 am PDT, Jul 2, 2019 · · 8.6 km deep · released about 610 lb of TNT

10 km30 km60 km120 km N San Benito County 31 kmMonterey County 58 kmMerced County 76 kmKings County 98 kmFresno County 103 kmSanta Clara County 114 kmStanislaus County 119 kmMadera County 119 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
10:48 am PDT on 2 July 2019 ()
Where
48 km (30 mi) east-northeast of Greenfield, CA · earthquakes near Greenfield
Magnitude
M 2.9 (md)
Depth
8.6 km below the surface
Felt
6 reports · strongest reported intensity III
Nearest
San Benito County, 31 km WNW
Nearest mapped fault
Great Valley thrust fault system, 18 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 2687 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 29 km (18 mi) from the epicentre. In Greenfield, 48 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.

How big was it?

This earthquake released about 610 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 25,000× 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 610 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 4.6 on 2017-11-13 — about 370 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.1 Northwest of Huron, California · 15 km E of this epicentre
  2. 5.9 10 km SE of Tres Pinos, California · 47 km WNW of this epicentre
  3. 5.8 Near Paicines, California · 47 km WNW of this epicentre
  4. 5.8 29 km NE of San Lucas, California · 23 km S of this epicentre
  5. 5.4 22 km SSW of Three Rocks, California · 32 km SE 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 36.5107, -120.7670. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 31 km (19 mi) WNW earthquakes near San Benito County
Monterey County, CA 58 km (36 mi) WSW earthquakes near Monterey County
Merced County, CA 76 km (47 mi) N earthquakes near Merced County
Kings County, CA 98 km (61 mi) ESE earthquakes near Kings County
Fresno County, CA 103 km (64 mi) ENE earthquakes near Fresno County
Santa Clara County, CA 114 km (71 mi) NW earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 1.6 16km NW of Pinnacles, CA
  2. 1.8 7km ENE of Pinnacles, CA
  3. 1.9 5km NNW of Pinnacles, CA
  4. 1.6 16km SSE of Tres Pinos, CA
  5. 1.6 9km NNE of Pinnacles, CA
  6. 1.5 8km NE of Pinnacles, CA
  7. 2.0 29km SW of South Dos Palos, CA
  8. 1.6 8km ESE of Pinnacles, CA
  9. 1.6 16km NW of Pinnacles, CA
  10. 1.5 22km NNE of San Ardo, CA
  11. 1.8 3km NNW of Pinnacles, CA
  12. 1.5 13km SE of Pinnacles, CA
  13. 1.6 22km WSW of New Idria, CA
  14. 2.9 20km S of Cantua Creek, CA
  15. 2.3 20km N of Coalinga, 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

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