QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

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 1.6 earthquake was recorded 5 km (3 mi) north-northwest of Aromas, CA, at 3:21 am PST on 21 February 2023 (11:21 UTC), 7.2 km deep.

USGS: 5km NNW of Aromas, CA

9 km (6 mi) E of Watsonville, CA · 43 km (27 mi) SSE of San Jose, CA

3:21 am PST, Feb 21, 2023 · · 7.2 km deep · released about 8.4 lb of TNT

10 km30 km60 km120 km N Santa Cruz County 32 kmSanta Clara County 33 kmSan Benito County 62 kmMonterey County 83 kmSan Mateo County 83 kmAlameda County 83 kmMerced County 89 kmStanislaus County 92 kmContra Costa County 113 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
3:21 am PST on 21 February 2023 ()
Where
5 km (3 mi) north-northwest of Aromas, CA · earthquakes near Aromas
Magnitude
M 1.6 (md)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Santa Cruz County, 32 km WNW
Nearest mapped fault
San Andreas fault, 5 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 1356 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 Aromas, 5 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: Watsonville 8 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 8.4 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 1,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× 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 8.4 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 5.1 on 2022-10-25 — about 140,000 times the energy of this one.

Before 2016, the USGS record lists 33 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 23 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 21 km N of this epicentre
  3. 6.3 22 km S of Davenport, California · 50 km WSW of this epicentre
  4. 6.2 Near San Jose, California · 43 km NNW of this epicentre
  5. 6.2 The 1984 Morgan Hill, California Earthquake · 43 km N 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 36.9270, -121.6658. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Cruz County, CA 32 km (20 mi) WNW earthquakes near Santa Cruz County
Santa Clara County, CA 33 km (20 mi) N earthquakes near Santa Clara County
San Benito County, CA 62 km (39 mi) SE earthquakes near San Benito County
Monterey County, CA 83 km (51 mi) SSE earthquakes near Monterey County
San Mateo County, CA 83 km (51 mi) NW earthquakes near San Mateo County
Alameda County, CA 83 km (52 mi) NNW earthquakes near Alameda 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. 4.4 1km NNW of Tres Pinos, CA
  2. 2.3 2km E of Aromas, CA
  3. 1.7 0km NNE of Tres Pinos, CA
  4. 1.9 8km NE of Interlaken, CA
  5. 1.9 1km NNE of Tres Pinos, CA
  6. 1.6 16km E of Seven Trees, CA
  7. 2.8 1km N of Tres Pinos, CA
  8. 2.4 16km SSE of Tres Pinos, CA
  9. 1.9 16km SSE of Tres Pinos, CA
  10. 1.8 3km ESE of Tres Pinos, CA
  11. 2.4 10km NE of Gilroy, CA
  12. 1.7 11km S of Tres Pinos, CA
  13. 1.7 10km SSW of Tres Pinos, CA
  14. 1.6 10km SSW of Tres Pinos, CA
  15. 1.7 10km S of Tres Pinos, 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.