QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Greenfield, CA

No earthquake was likely felt in Greenfield in the 24 hours to 3:53 am PST (11:53 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 1.6 earthquake was recorded 43 km (27 mi) south-southwest of Greenfield, CA, at 11:19 pm PST on 6 March 2025 (07:19 UTC), 5.7 km deep. 1 person has reported feeling it to USGS.

USGS: 11 km SE of Lopez Point, CA

81 km (51 mi) SSE of Salinas, CA

11:19 pm PST, Mar 6, 2025 · · 5.7 km deep · released about 6.6 lb of TNT

Every earthquake near Greenfield Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Monterey County 32 kmSan Benito County 78 kmSan Luis Obispo County 112 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
11:19 pm PST on 6 March 2025 ()
Where
43 km (27 mi) south-southwest of Greenfield, CA · earthquakes near Greenfield
Magnitude
M 1.6 (md)
Depth
5.7 km below the surface
Felt
1 report
Nearest
Monterey County, 32 km NNE
Nearest mapped fault
San Gregorio fault, 2 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 610 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 9 km (6 mi) from the epicentre. In Greenfield, 43 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 6.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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 2021-10-25 — about 43,000 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 10 km NE of San Simeon, California · 44 km SE of this epicentre
  2. 6.2 28km NW of Cambria, CA · 30 km SSE of this epicentre
  3. 5.2 26km NNW of Lake Nacimiento, CA · 43 km E of this epicentre
  4. 5.2 25 km NW of San Simeon, California · 18 km SSE of this epicentre
  5. 5.2 22 km NW of San Simeon, California · 21 km SSE 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 35.9735, -121.4538. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Monterey County, CA 32 km (20 mi) NNE earthquakes near Monterey County
San Benito County, CA 78 km (49 mi) NNE earthquakes near San Benito County
San Luis Obispo County, CA 112 km (69 mi) SE earthquakes near San Luis Obispo County
Santa Cruz County, CA 126 km (78 mi) NNW earthquakes near Santa Cruz County

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

Aftershocks so far

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

  1. 1.9 23 km S of Lopez Point, CA
  2. 2.6 21 km NNE of San Simeon, CA
  3. 1.9 27 km S of Lopez Point, CA
  4. 1.8 10 km SE of Lopez Point, CA
  5. 1.6 27 km SSE of Lopez Point, CA
  6. 3.2 15 km NNW of San Simeon, CA
  7. 2.8 24 km SSE of Lopez Point, CA
  8. 2.3 20 km NNW of San Simeon, CA
  9. 2.2 6 km SW of San Ardo, CA
  10. 2.0 15 km WNW of Lake Nacimiento, CA
  11. 2.3 15 km WNW of Lake Nacimiento, CA
  12. 1.6 8 km WSW of San Ardo, CA
  13. 2.5 17 km SSE of Lopez Point, CA
  14. 1.6 25 km SSE of Lopez Point, CA
  15. 1.8 17 km WNW of San Simeon, 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.