QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near San Juan Bautista, CA

Yes: an earthquake was likely felt in San Juan Bautista in the last 24 hours. M 2.0, 4 km (2 mi) SSW of San Juan Bautista, at 2:11 am PST on 11 November 2026 (10:11 UTC); the estimated shaking in San Juan Bautista was intensity II (weak). Every earthquake near San Juan Bautista

This page: a magnitude 1.8 earthquake was recorded 6 km (4 mi) south of San Juan Bautista, CA, at 8:59 pm PDT on 17 March 2021 (03:59 UTC), 7.5 km deep.

USGS: 6km S of San Juan Bautista, CA

15 km (9 mi) NE of Salinas, CA · 62 km (38 mi) SSE of San Jose, CA

8:59 pm PDT, Mar 17, 2021 · · 7.5 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N San Benito County 44 kmSanta Cruz County 49 kmSanta Clara County 50 kmMonterey County 64 kmMerced County 84 kmStanislaus County 97 kmAlameda County 101 kmSan Mateo County 102 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
8:59 pm PDT on 17 March 2021 ()
Where
6 km (4 mi) south of San Juan Bautista, CA · earthquakes near San Juan Bautista
Magnitude
M 1.8 (md)
Depth
7.5 km below the surface
Felt
no reports yet
Nearest
San Benito County, 44 km ESE
Nearest mapped fault
Zayante-Vergeles 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 2064 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 11 km (7 mi) from the epicentre. In San Juan Bautista, 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: Prunedale, Hollister, Ridgemark, Aromas, Boronda, Salinas.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 28,000 times the energy of this one.

Before 2016, the USGS record lists 26 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 41 km NW of this epicentre
  2. 6.5 Near Morgan Hill, California · 37 km NNW of this epicentre
  3. 5.9 10 km SE of Tres Pinos, California · 28 km ESE of this epicentre
  4. 5.8 Near Watsonville, California · 23 km NW of this epicentre
  5. 5.8 Near Paicines, California · 28 km ESE 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 36.7925, -121.5275. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Benito County, CA 44 km (27 mi) ESE earthquakes near San Benito County
Santa Cruz County, CA 49 km (31 mi) WNW earthquakes near Santa Cruz County
Santa Clara County, CA 50 km (31 mi) NNW earthquakes near Santa Clara County
Monterey County, CA 64 km (40 mi) SSE earthquakes near Monterey County
Merced County, CA 84 km (52 mi) ENE earthquakes near Merced County
Stanislaus County, CA 97 km (61 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. 1.8 7km SW of Ridgemark, CA
  2. 3.0 3km SW of San Juan Bautista, CA
  3. 2.2 6km NNW of Pinnacles, CA
  4. 1.9 5km ESE of Interlaken, CA
  5. 2.2 7km ENE of Aromas, CA
  6. 2.3 9km SSE of San Juan Bautista, CA
  7. 1.8 10km ENE of Morgan Hill, CA
  8. 1.6 17km N of Pinnacles, CA
  9. 2.4 5km ESE of Aromas, CA
  10. 2.1 5km WNW of San Juan Bautista, CA
  11. 1.6 15km NW of Pinnacles, CA
  12. 2.1 9km NW of Pinnacles, CA
  13. 2.1 5km NNE of Pinnacles, CA
  14. 1.6 7km ESE of Prunedale, CA
  15. 2.3 2km N 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.