QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Ridgemark, CA

No earthquake was likely felt in Ridgemark in the 24 hours to 4:06 am PST (12:06 UTC). The last one was M 1.6, 11 km (7 mi) S, at 11:35 pm PST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Ridgemark

This page: a magnitude 2.1 earthquake was recorded 10 km (6 mi) southwest of Ridgemark, CA, at 8:52 pm PST on 14 November 2017 (04:52 UTC), 7.1 km deep.

USGS: 10 km SW of Ridgemark, California

71 km (44 mi) SSE of San Jose, CA · 19 km (12 mi) ENE of Salinas, CA

8:52 pm PST, Nov 14, 2017 · · 7.1 km deep · released about 38 lb of TNT

10 km30 km60 km120 km N San Benito County 34 kmMonterey County 56 kmSanta Clara County 59 kmSanta Cruz County 60 kmMerced County 81 kmStanislaus County 99 kmAlameda County 110 kmSan Mateo 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
8:52 pm PST on 14 November 2017 ()
Where
10 km (6 mi) southwest of Ridgemark, CA · earthquakes near Ridgemark
Magnitude
M 2.1 (md)
Depth
7.1 km below the surface
Felt
no reports yet
Nearest
San Benito County, 34 km ESE
Nearest mapped fault
San Andreas fault, 4 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 3285 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 15 km (9 mi) from the epicentre. In Ridgemark, 10 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: Hollister 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 38 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 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 4.6 on 2017-11-13 — about 5,800 times the energy of this one.

Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 Near Morgan Hill, California · 45 km NNW of this epicentre
  2. 5.9 10 km SE of Tres Pinos, California · 19 km E of this epicentre
  3. 5.8 Near Watsonville, California · 34 km NW of this epicentre
  4. 5.8 Near Paicines, California · 18 km ESE of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 41 km N 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 36.7368, -121.4323. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 34 km (21 mi) ESE earthquakes near San Benito County
Monterey County, CA 56 km (35 mi) S earthquakes near Monterey County
Santa Clara County, CA 59 km (36 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 60 km (37 mi) WNW earthquakes near Santa Cruz County
Merced County, CA 81 km (50 mi) NE earthquakes near Merced County
Stanislaus County, CA 99 km (62 mi) NNE earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 1.6 15km NW of Pinnacles, CA
  2. 1.6 9km NW of Pinnacles, CA
  3. 1.7 12km NW of Pinnacles, CA
  4. 1.6 6km SW of Ridgemark, CA
  5. 2.0 3km NNW of Pinnacles, CA
  6. 1.8 16km NW of Pinnacles, CA
  7. 2.8 17 km SSE of Tres Pinos, California
  8. 2.0 12km NW of Pinnacles, CA
  9. 1.6 14km NW of Pinnacles, CA
  10. 1.5 26km E of Tres Pinos, CA
  11. 2.2 15km NW of Pinnacles, CA
  12. 1.7 4 km E of Aromas, California
  13. 2.2 20 km SSE of Tres Pinos, California
  14. 2.4 20 km SSE of Tres Pinos, California
  15. 1.9 9 km NE of Gilroy, California

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.