QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Aromas, CA

Yes: an earthquake was likely felt in Aromas in the last 24 hours. M 2.6, in Aromas, at 11:40 am PST on 12 November 2026 (19:40 UTC); the estimated shaking in Aromas was intensity III (weak). Every earthquake near Aromas

This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) east-northeast of Aromas, CA, at 9:16 pm PDT on 17 September 2017 (04:16 UTC), 6.8 km deep.

USGS: 5 km ENE of Aromas, California

12 km (7 mi) S of Gilroy, CA · 49 km (30 mi) SSE of San Jose, CA

9:16 pm PDT, Sep 17, 2017 · · 6.8 km deep · released about 14 lb of TNT

Every earthquake near Aromas Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 37 kmSanta Cruz County 40 kmSan Benito County 55 kmMonterey County 77 kmMerced County 83 kmAlameda County 88 kmStanislaus County 90 kmSan Mateo County 90 kmContra Costa County 118 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
9:16 pm PDT on 17 September 2017 ()
Where
5 km (3 mi) east-northeast of Aromas, CA · earthquakes near Aromas
Magnitude
M 1.8 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 37 km NNW
Nearest mapped fault
San Andreas 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 3333 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 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.

Earthquakes near other towns within 30 km: San Juan Bautista, Gilroy, Las Lomas, Interlaken, Pajaro, Watsonville.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 4.2 on 2016-07-19 — about 4,600 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 · 30 km WNW of this epicentre
  2. 6.5 Near Morgan Hill, California · 24 km NNW of this epicentre
  3. 6.2 Near San Jose, California · 48 km NNW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 46 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 36.8998, -121.5830. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 37 km (23 mi) NNW earthquakes near Santa Clara County
Santa Cruz County, CA 40 km (25 mi) WNW earthquakes near Santa Cruz County
San Benito County, CA 55 km (34 mi) SE earthquakes near San Benito County
Monterey County, CA 77 km (48 mi) SSE earthquakes near Monterey County
Merced County, CA 83 km (52 mi) ENE earthquakes near Merced County
Alameda County, CA 88 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

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

  1. 2.3 9 km NNE of San Juan Bautista, California
  2. 2.2 8 km N of San Juan Bautista, California
  3. 2.0 15 km SSE of Tres Pinos, California
  4. 2.7 15 km SSE of Tres Pinos, California
  5. 2.4 2 km N of Aromas, California
  6. 2.1 20 km SSE of Tres Pinos, California
  7. 2.2 15 km E of Seven Trees, California
  8. 1.7 2 km E of Aromas, California
  9. 2.3 9 km S of Tres Pinos, California
  10. 2.0 10 km S of Tres Pinos, California
  11. 1.7 6 km SW of Gilroy, California
  12. 1.5 16 km SE of Tres Pinos, California
  13. 2.0 19 km SSE of Tres Pinos, California
  14. 2.1 20 km SSE of Tres Pinos, California
  15. 1.9 19 km SSE 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.