QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Ridgemark, CA

Yes. A magnitude 1.7 earthquake was recorded 3 km (2 mi) SW of Ridgemark, CA, at 6:43 pm PDT on 12 July 2016 (01:43 UTC), 8.2 km deep.

This was on 12 July 2016. The latest near Ridgemark: M 2.6 on 23 September 2026.

USGS: 2 km SW of Ridgemark, California

67 km (42 mi) SE of San Jose, CA · 25 km (15 mi) ENE of Salinas, CA

6:43 pm PDT, Jul 12, 2016 · · 8.2 km deep · released about 11 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 60 kmMonterey County 62 kmMerced County 74 kmStanislaus County 92 kmAlameda County 106 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
6:43 pm PDT on 12 July 2016 ()
Where
3 km (2 mi) SW of Ridgemark, CA · earthquakes near Ridgemark
Magnitude
M 1.7 (md)
Depth
8.2 km below the surface
Felt
no reports yet
Nearest
San Benito County, 34 km SE
Nearest mapped fault
Calaveras fault, 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 3532 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 9 km (6 mi) from the epicentre. In Ridgemark, 3 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: Ridgemark 3 km, intensity II · Hollister 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 970,000× the energy of this one
  3. Around the size people start to feel M 3.0 86× the energy of this one
  4. This earthquake M 1.7 about 11 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 · 16 km ESE of this epicentre
  3. 5.8 Near Watsonville, California · 33 km WNW of this epicentre
  4. 5.8 Near Paicines, California · 18 km SE of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 36 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 36.7940, -121.3880. 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 55 km (34 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 60 km (37 mi) WNW earthquakes near Santa Cruz County
Monterey County, CA 62 km (38 mi) S earthquakes near Monterey County
Merced County, CA 74 km (46 mi) NE earthquakes near Merced County
Stanislaus County, CA 92 km (57 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. 2.2 25 km WSW of Volta, California
  2. 1.6 13 km S of Tres Pinos, California
  3. 1.9 7 km WSW of Gilroy, California
  4. 2.1 23 km NE of Greenfield, California
  5. 2.1 9 km E of Gilroy, California
  6. 1.8 10 km S of Tres Pinos, California
  7. 1.7 Central California
  8. 1.7 3 km W of San Juan Bautista, California
  9. 3.0 18 km SSE of Tres Pinos, California
  10. 2.9 13 km SSE of Tres Pinos, California
  11. 2.4 10 km S of Tres Pinos, California
  12. 1.8 8 km ENE of Morgan Hill, California
  13. 1.6 10 km S of Tres Pinos, California
  14. 1.7 11 km S of Tres Pinos, California
  15. 1.7 11 km S of Tres Pinos, 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.