QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6mw

Earthquake near Aromas, CA

Yes: an earthquake was likely felt in Aromas in the last 24 hours. M 2.0, 11 km (7 mi) SE of Aromas, at 2:11 am PST on 11 November 2026 (10:11 UTC); the estimated shaking in Aromas was intensity II (weak). Every earthquake near Aromas

This page: a magnitude 3.6 earthquake was recorded 6 km (4 mi) north-northwest of Aromas, CA, at 10:02 pm PST on 23 January 2018 (06:02 UTC), 7.1 km deep. 5,228 people have reported feeling it to USGS.

USGS: 6km NNW of Aromas, CA

10 km (6 mi) E of Watsonville, CA · 42 km (26 mi) SSE of San Jose, CA

10:02 pm PST, Jan 23, 2018 · · 7.1 km deep · released about 3.8 tons of TNT

Every earthquake near Aromas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 32 kmSanta Cruz County 32 kmSan Benito County 63 kmAlameda County 82 kmSan Mateo County 82 kmMonterey County 83 kmMerced County 88 kmStanislaus County 91 kmContra Costa 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
10:02 pm PST on 23 January 2018 ()
Where
6 km (4 mi) north-northwest of Aromas, CA · earthquakes near Aromas
Magnitude
M 3.6 (mw)
Depth
7.1 km below the surface
Felt
5,228 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Santa Clara County, 32 km N
Nearest mapped fault
Sargent 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 2700 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 69 km (43 mi) from the epicentre. In Aromas, 6 km away, the estimate is intensity III (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: Watsonville 9 km, intensity III · Gilroy 11 km, intensity III · Prunedale 18 km, intensity III · Morgan Hill 21 km, intensity III · Hollister 25 km, intensity III · Capitola 26 km, intensity III · Live Oak 29 km, intensity III · Salinas 29 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 45,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,400× the energy of this one
  4. This earthquake M 3.6 about 3.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 7.9× more

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 4.2 on 2016-07-19 — about 8.5 times the energy of this one.

Before 2016, the USGS record lists 32 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 22 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 19 km N of this epicentre
  3. 6.2 Near San Jose, California · 42 km NNW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 41 km N of this epicentre
  5. 6.1 Near San Jose, California · 32 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 36.9373, -121.6610. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 32 km (20 mi) N earthquakes near Santa Clara County
Santa Cruz County, CA 32 km (20 mi) WNW earthquakes near Santa Cruz County
San Benito County, CA 63 km (39 mi) SE earthquakes near San Benito County
Alameda County, CA 82 km (51 mi) NNW earthquakes near Alameda County
San Mateo County, CA 82 km (51 mi) NW earthquakes near San Mateo County
Monterey County, CA 83 km (52 mi) SSE earthquakes near Monterey County

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

Aftershocks so far

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

  1. 2.1 12km S of Tres Pinos, CA
  2. 1.6 3km S of San Juan Bautista, CA
  3. 1.8 15km NW of Pinnacles, CA
  4. 2.1 6km SW of Gilroy, CA
  5. 1.6 27km NE of Hollister, CA
  6. 1.6 13km S of Tres Pinos, CA
  7. 2.7 11km NNW of Hollister, CA
  8. 3.4 11km NNW of Hollister, CA
  9. 1.9 6km SW of Gilroy, CA
  10. 2.1 6km WSW of Gilroy, CA
  11. 2.3 12km SSE of Tres Pinos, CA
  12. 2.5 10km E of Gilroy, CA
  13. 1.9 10km E of Gilroy, CA
  14. 2.6 10km E of Gilroy, CA
  15. 3.3 10km E of Gilroy, 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.