QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

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 1.6 earthquake was recorded 6 km (4 mi) southwest of Ridgemark, CA, at 5:17 pm PDT on 26 July 2018 (00:17 UTC), 9.9 km deep.

USGS: 6km SW of Ridgemark, CA

68 km (42 mi) SSE of San Jose, CA · 22 km (14 mi) ENE of Salinas, CA

5:17 pm PDT, Jul 26, 2018 · · 9.9 km deep · released about 8.7 lb of TNT

Every earthquake near Ridgemark Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Benito County 34 kmSanta Clara County 55 kmSanta Cruz County 59 kmMonterey County 60 kmMerced County 77 kmStanislaus County 95 kmAlameda County 107 kmSan Mateo County 111 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
5:17 pm PDT on 26 July 2018 ()
Where
6 km (4 mi) southwest of Ridgemark, CA · earthquakes near Ridgemark
Magnitude
M 1.6 (md)
Depth
9.9 km below the surface
Felt
no reports yet
Nearest
San Benito County, 34 km ESE
Nearest mapped fault
San Andreas 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 3030 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 6 km (4 mi) from the epicentre. In Ridgemark, 6 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.

Earthquakes near other towns within 30 km: Hollister, San Juan Bautista, Prunedale, Aromas, Salinas, Chualar.

How big was it?

This earthquake released about 8.7 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 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.7 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 26,000 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 · 42 km NNW of this epicentre
  2. 5.9 10 km SE of Tres Pinos, California · 18 km ESE of this epicentre
  3. 5.8 Near Watsonville, California · 32 km NW of this epicentre
  4. 5.8 Near Paicines, California · 19 km SE of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 38 km NNW 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 36.7762, -121.4110. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 34 km (21 mi) ESE earthquakes near San Benito County
Santa Clara County, CA 55 km (34 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 59 km (37 mi) WNW earthquakes near Santa Cruz County
Monterey County, CA 60 km (37 mi) S earthquakes near Monterey County
Merced County, CA 77 km (48 mi) NE earthquakes near Merced County
Stanislaus County, CA 95 km (59 mi) NNE earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 2.0 1km NE of Pinnacles, CA
  2. 2.4 24km SW of Gustine, CA
  3. 1.6 16km NW of Pinnacles, CA
  4. 1.6 7km NE of Ridgemark, CA
  5. 1.8 13km S of Tres Pinos, CA
  6. 2.5 9km NE of San Martin, CA
  7. 1.8 9km N of Pinnacles, CA
  8. 2.5 16km SSE of Tres Pinos, CA
  9. 2.5 7km ENE of Pinnacles, CA
  10. 1.9 12km SE of Pinnacles, CA
  11. 2.0 12km SE of Pinnacles, CA
  12. 2.4 7km ENE of Pinnacles, CA
  13. 2.0 5km WNW of San Juan Bautista, CA
  14. 2.0 2km NNE of Pinnacles, CA
  15. 1.8 23km SW of Gustine, 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.