Earthquake · reviewed by a seismologist
M 1.9md
Earthquake near Greenfield, CA
No earthquake was likely felt in Greenfield in the 24 hours to 12:49 am PST (08:49 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 1.9 earthquake was recorded 49 km (30 mi) northeast of Greenfield, CA, at 4:02 am PDT on 15 August 2022 (11:02 UTC), less than 1 km deep. 1 person has reported feeling it to USGS.
USGS: 20km NNW of New Idria, CA
- When
- 4:02 am PDT on 15 August 2022 ()
- Where
- 49 km (30 mi) northeast of Greenfield, CA · earthquakes near Greenfield
- Magnitude
- M 1.9 (md)
- Depth
- 0.8 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- San Benito County, 27 km W
- Nearest mapped fault
- Great Valley thrust fault system, 15 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 1550 days ago
Earthquake alerts for Greenfield, CA
Get a notification in this browser when USGS records an earthquake near Greenfield, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 15 km (9 mi) from the epicentre. In Greenfield, 49 km away, the estimate is intensity I (not felt). 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
- Magna, Utah 2020 M 5.7 440,000× the energy of this one
- Around the size people start to feel M 3.0 39× the energy of this one
- This earthquake M 1.9 about 25 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 4.7 on 2019-10-15 — about 14,000 times the energy of this one.
Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:
- 6.1 Northwest of Huron, California · 19 km ESE of this epicentre
- 5.9 10 km SE of Tres Pinos, California · 42 km WNW of this epicentre
- 5.8 Near Paicines, California · 42 km WNW of this epicentre
- 5.8 29 km NE of San Lucas, California · 30 km S of this epicentre
- 5.5 12 km S of Tres Pinos, California · 47 km WNW 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 36.5672, -120.7925. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Benito County, CA | 27 km (17 mi) | W | earthquakes near San Benito County |
| Monterey County, CA | 59 km (37 mi) | SW | earthquakes near Monterey County |
| Merced County, CA | 70 km (44 mi) | N | earthquakes near Merced County |
| Kings County, CA | 103 km (64 mi) | ESE | earthquakes near Kings County |
| Fresno County, CA | 104 km (64 mi) | ENE | earthquakes near Fresno County |
| Santa Clara County, CA | 108 km (67 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
60 earthquakes have been recorded within 50 km since this one.
- 2.4 5km NNE of Pinnacles, CA
- 3.2 16km NW of Pinnacles, CA
- 2.2 4km ENE of Pinnacles, CA
- 1.8 3km NNW of Pinnacles, CA
- 1.5 13km SE of Pinnacles, CA
- 1.7 23km WSW of New Idria, CA
- 2.6 3km NNW of Pinnacles, CA
- 1.8 4km NNE of Pinnacles, CA
- 1.9 4km NNE of Pinnacles, CA
- 2.4 4km NNE of Pinnacles, CA
- 1.9 4km NNE of Pinnacles, CA
- 1.8 5km NNE of Pinnacles, CA
- 2.0 5km NNE of Pinnacles, CA
- 2.2 4km NNE of Pinnacles, CA
- 2.5 4km N of Pinnacles, 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
- 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.