Earthquake near Greenfield, CA

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 17 km (11 mi) from the epicentre. In Greenfield, 24 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.

Earthquakes near other towns within 30 km: Soledad, King City.

How big was it?

This earthquake released about 47 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 320,000× the energy of this one
2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
3. Around the size people start to feel M 3.0 20× the energy of this one
4. This earthquake M 2.1 about 47 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 1,400 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

1. 6.1 Northwest of Huron, California · 40 km E of this epicentre May 26, 1905
2. 5.9 10 km SE of Tres Pinos, California · 33 km NNW of this epicentre Apr 9, 1961
3. 5.8 Near Paicines, California · 29 km NW of this epicentre Aug 6, 1916
4. 5.8 29 km NE of San Lucas, California · 31 km SE of this epicentre Jul 25, 1926
5. 5.5 12 km S of Tres Pinos, California · 33 km NW of this epicentre Apr 9, 1961

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 36.4683, -121.0485. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.3 24 km NE of Greenfield, California 20:21 UTC
2. 1.7 23 km ENE of Soledad, California 08:22 UTC
3. 2.3 25 km NE of Soledad, California 16:15 UTC
4. 1.6 25 km NE of Soledad, California 16:05 UTC
5. 1.6 25 km NE of Soledad, California 15:55 UTC
6. 1.9 23 km NE of Soledad, California 21:22 UTC
7. 2.2 24 km NE of Soledad, California 20:03 UTC
8. 1.6 26 km NE of Soledad, California 19:52 UTC
9. 1.6 23 km NE of Soledad, California 19:39 UTC
10. 1.7 21 km NE of Soledad, California 03:39 UTC
11. 2.8 22 km NE of San Ardo, California 16:45 UTC
12. 1.6 9 km SSW of Tres Pinos, California 03:23 UTC
13. 2.3 1 km ENE of Ridgemark, California 09:37 UTC
14. 2.8 1 km ENE of Ridgemark, California 09:32 UTC
15. 1.6 23 km NE of Soledad, California 08:34 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:45 UTC. 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.