QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

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 2.0 earthquake was recorded 8 km (5 mi) northeast of Ridgemark, CA, at 8:21 am PDT on 14 April 2018 (15:21 UTC), 6.8 km deep.

USGS: 8km NE of Ridgemark, CA

66 km (41 mi) SE of San Jose, CA · 30 km (19 mi) ESE of Gilroy, CA

8:21 am PDT, Apr 14, 2018 · · 6.8 km deep · released about 29 lb of TNT

10 km30 km60 km120 km N San Benito County 34 kmSanta Clara County 53 kmMerced County 63 kmSanta Cruz County 65 kmMonterey County 69 kmStanislaus County 82 kmAlameda County 103 kmSan Mateo County 113 kmSan Joaquin County 119 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
8:21 am PDT on 14 April 2018 ()
Where
8 km (5 mi) northeast of Ridgemark, CA · earthquakes near Ridgemark
Magnitude
M 2.0 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
San Benito County, 34 km SE
Nearest mapped fault
Quien Sabe fault, under 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 3124 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 14 km (9 mi) from the epicentre. In Ridgemark, 8 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 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 29 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 520,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 370,000× the energy of this one
  3. Around the size people start to feel M 3.0 33× the energy of this one
  4. This earthquake M 2.0 about 29 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 7,700 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 Near Morgan Hill, California · 41 km NW of this epicentre
  2. 5.9 10 km SE of Tres Pinos, California · 16 km SSE of this epicentre
  3. 5.8 Near Watsonville, California · 37 km WNW of this epicentre
  4. 5.8 Near Paicines, California · 22 km SSE of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 33 km NW 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 36.8628, -121.3020. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 34 km (21 mi) SE earthquakes near San Benito County
Santa Clara County, CA 53 km (33 mi) NW earthquakes near Santa Clara County
Merced County, CA 63 km (39 mi) NE earthquakes near Merced County
Santa Cruz County, CA 65 km (40 mi) WNW earthquakes near Santa Cruz County
Monterey County, CA 69 km (43 mi) S earthquakes near Monterey County
Stanislaus County, CA 82 km (51 mi) NNE earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 2.3 4km NNW of Pinnacles, CA
  2. 2.0 8km ENE of Gilroy, CA
  3. 1.7 3km SSW of San Juan Bautista, CA
  4. 2.3 3km SSW of San Juan Bautista, CA
  5. 2.3 9km ENE of San Martin, CA
  6. 1.7 17km SSE of Tres Pinos, CA
  7. 1.8 4km SSE of San Juan Bautista, CA
  8. 1.7 9km NNW of Pinnacles, CA
  9. 1.8 5km NNW of Aromas, CA
  10. 2.0 10km SSW of Ridgemark, CA
  11. 2.2 10km NNW of Hollister, CA
  12. 2.4 2km ENE of Pinnacles, CA
  13. 2.6 10km NNW of Hollister, CA
  14. 1.8 5km SSW of Gilroy, CA
  15. 1.9 7km ESE 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.