QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Aromas, CA

No earthquake was likely felt in Aromas in the 24 hours to 5:36 am PST (13:36 UTC). The last one was M 2.0, 11 km (7 mi) SE, at 2:11 am PST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Aromas

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) east of Aromas, CA, at 11:11 am PST on 28 December 2023 (19:11 UTC), 1.7 km deep.

USGS: 3 km E of Aromas, CA

14 km (8 mi) S of Gilroy, CA · 49 km (31 mi) SSE of San Jose, CA

11:11 am PST, Dec 28, 2023 · · 1.7 km deep · released about 17 lb of TNT

Every earthquake near Aromas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 38 kmSanta Cruz County 38 kmSan Benito County 56 kmMonterey County 76 kmMerced County 86 kmAlameda County 89 kmSan Mateo County 90 kmStanislaus County 92 kmContra Costa County 119 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
11:11 am PST on 28 December 2023 ()
Where
3 km (2 mi) east of Aromas, CA · earthquakes near Aromas
Magnitude
M 1.8 (md)
Depth
1.7 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 38 km N
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 1044 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 14 km (9 mi) from the epicentre. In Aromas, 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: Prunedale 13 km, intensity II · Watsonville 14 km, intensity II · Gilroy 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 70,000 times the energy of this one.

Before 2016, the USGS record lists 30 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 29 km NW of this epicentre
  2. 6.5 Near Morgan Hill, California · 25 km N of this epicentre
  3. 6.2 Near San Jose, California · 49 km NNW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 48 km N of this epicentre
  5. 6.1 Near San Jose, California · 39 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 36.8858, -121.6082. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 38 km (24 mi) N earthquakes near Santa Clara County
Santa Cruz County, CA 38 km (24 mi) WNW earthquakes near Santa Cruz County
San Benito County, CA 56 km (35 mi) ESE earthquakes near San Benito County
Monterey County, CA 76 km (47 mi) SSE earthquakes near Monterey County
Merced County, CA 86 km (53 mi) ENE earthquakes near Merced County
Alameda County, CA 89 km (55 mi) NNW earthquakes near Alameda County

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

Aftershocks so far

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

  1. 2.2 12 km NW of Pinnacles, CA
  2. 1.7 10 km NW of Pinnacles, CA
  3. 1.8 9 km NW of Pinnacles, CA
  4. 2.5 10 km NW of Pinnacles, CA
  5. 2.6 10 km NW of Pinnacles, CA
  6. 1.6 6 km SSW of Gilroy, CA
  7. 1.6 3 km WSW of San Juan Bautista, CA
  8. 2.6 6 km SSE of San Juan Bautista, CA
  9. 2.2 3 km SSW of San Juan Bautista, CA
  10. 1.5 4 km NE of Tres Pinos, CA
  11. 1.7 24 km W of Los Banos, CA
  12. 1.6 11 km NW of Pinnacles, CA
  13. 2.5 8 km NE of Interlaken, CA
  14. 1.8 11 km NE of Hollister, CA
  15. 2.2 9 km NW 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.