QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near South Dos Palos, CA

No earthquake was likely felt in South Dos Palos in the 24 hours to 6:17 pm PST (02:17 UTC). The last one was M 3.9, 64 km (40 mi) SW, at 3:19 am PDT on 11 August 2026, estimated intensity II (weak) in town; 34 felt reports to USGS. Every earthquake near South Dos Palos

This page: a magnitude 2.8 earthquake was recorded 23 km (14 mi) south of South Dos Palos, CA, at 11:08 pm PST on 9 March 2021 (07:08 UTC), 4.2 km deep. 5 people have reported feeling it to USGS.

USGS: 23km S of South Dos Palos, CA

59 km (37 mi) WSW of Madera, CA · 116 km (72 mi) ESE of San Jose, CA

11:08 pm PST, Mar 9, 2021 · · 4.2 km deep · released about 450 lb of TNT

10 km30 km60 km120 km N San Benito County 38 kmMerced County 48 kmMonterey County 80 kmFresno County 93 kmStanislaus County 93 kmMadera County 98 kmSanta Clara County 102 kmKings County 110 kmMariposa County 114 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
11:08 pm PST on 9 March 2021 ()
Where
23 km (14 mi) south of South Dos Palos, CA · earthquakes near South Dos Palos
Magnitude
M 2.8 (md)
Depth
4.2 km below the surface
Felt
5 reports · strongest reported intensity III
Nearest
San Benito County, 38 km WSW
Nearest mapped fault
Great Valley thrust fault system, 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 1557 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 26 km (16 mi) from the epicentre. In South Dos Palos, 23 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: South Dos Palos 23 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 450 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 34,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 24,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.1× the energy of this one
  4. This earthquake M 2.8 about 450 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 4.3 on 2021-01-02 — about 200 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.1 Northwest of Huron, California · 30 km SSE of this epicentre
  2. 5.9 10 km SE of Tres Pinos, California · 47 km W of this epicentre
  3. 5.2 25 km NE of Soledad, California · 42 km WSW of this epicentre
  4. 5.0 21 km NE of Soledad, California · 47 km WSW of this epicentre
  5. 5.0 28km NE of King City, CA · 46 km SSW 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 36.7603, -120.6995. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 38 km (24 mi) WSW earthquakes near San Benito County
Merced County, CA 48 km (30 mi) N earthquakes near Merced County
Monterey County, CA 80 km (50 mi) SW earthquakes near Monterey County
Fresno County, CA 93 km (58 mi) E earthquakes near Fresno County
Stanislaus County, CA 93 km (58 mi) NNW earthquakes near Stanislaus County
Madera County, CA 98 km (61 mi) ENE earthquakes near Madera County

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

Aftershocks so far

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

  1. 1.6 29km NE of Pinnacles, CA
  2. 3.2 29km NE of Pinnacles, CA
  3. 1.5 9km SE of Pinnacles, CA
  4. 2.1 28km NE of Pinnacles, CA
  5. 2.2 20km SE of Pinnacles, CA
  6. 2.4 13km NW of Pinnacles, CA
  7. 1.6 25km SSW of Los Banos, CA
  8. 2.5 7km NNW of Pinnacles, CA
  9. 1.5 12km NW of Pinnacles, CA
  10. 1.9 7km NNW of Pinnacles, CA
  11. 2.2 11km NE of New Idria, CA
  12. 1.8 14km ESE of Pinnacles, CA
  13. 2.1 23km S of South Dos Palos, CA
  14. 2.2 6km NNW of Pinnacles, CA
  15. 1.6 17km 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

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