QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Ridgemark, CA

Yes: an earthquake was likely felt in Ridgemark in the last 24 hours. M 1.6, 11 km (7 mi) S of Ridgemark, at 11:35 pm PST on 11 November 2026 (07:35 UTC); the estimated shaking in Ridgemark was intensity II (weak). Every earthquake near Ridgemark

This page: a magnitude 2.7 earthquake was recorded 3 km (2 mi) west of Ridgemark, CA, at 10:37 am PDT on 26 September 2024 (17:37 UTC), 9.7 km deep. 8 people have reported feeling it to USGS.

USGS: 3 km W of Ridgemark, CA

66 km (41 mi) SE of San Jose, CA · 25 km (15 mi) ENE of Salinas, CA

10:37 am PDT, Sep 26, 2024 · · 9.7 km deep · released about 330 lb of TNT

10 km30 km60 km120 km N San Benito County 35 kmSanta Clara County 53 kmSanta Cruz County 59 kmMonterey County 64 kmMerced County 74 kmStanislaus County 91 kmAlameda County 104 kmSan Mateo County 110 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
10:37 am PDT on 26 September 2024 ()
Where
3 km (2 mi) west of Ridgemark, CA · earthquakes near Ridgemark
Magnitude
M 2.7 (md)
Depth
9.7 km below the surface
Felt
8 reports · strongest reported intensity III
Nearest
San Benito County, 35 km SE
Nearest mapped fault
Calaveras fault, 1 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 706 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 23 km (14 mi) from the epicentre. In Ridgemark, 3 km away, the estimate is intensity III (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: Hollister 5 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 330 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 46,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 33,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.9× the energy of this one
  4. This earthquake M 2.7 about 330 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 1,100 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 50 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 40 km NNW of this epicentre
  3. 5.9 10 km SE of Tres Pinos, California · 18 km ESE of this epicentre
  4. 5.8 Near Watsonville, California · 31 km WNW of this epicentre
  5. 5.8 Near Paicines, California · 20 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 36.8092, -121.3965. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 35 km (22 mi) SE earthquakes near San Benito County
Santa Clara County, CA 53 km (33 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 59 km (37 mi) WNW earthquakes near Santa Cruz County
Monterey County, CA 64 km (40 mi) S earthquakes near Monterey County
Merced County, CA 74 km (46 mi) NE earthquakes near Merced County
Stanislaus County, CA 91 km (56 mi) NNE earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 1.9 16 km S of Tres Pinos, CA
  2. 2.8 5 km SE of Aromas, CA
  3. 1.7 13 km S of Tres Pinos, CA
  4. 1.7 2 km E of Aromas, CA
  5. 1.8 6 km NW of Pinnacles, CA
  6. 1.5 2 km E of Aromas, CA
  7. 1.8 5 km E of Pinnacles, CA
  8. 1.7 1 km of Pinnacles, CA
  9. 1.9 6 km W of San Juan Bautista, CA
  10. 1.9 5 km W of San Juan Bautista, CA
  11. 1.8 9 km NNW of Pinnacles, CA
  12. 2.1 10 km NNW of Pinnacles, CA
  13. 1.7 10 km SSW of Tres Pinos, CA
  14. 1.6 22 km SW of Gustine, CA
  15. 1.8 14 km SSW of Tres Pinos, 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.