quarry blast · 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
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.6 quarry blast was recorded 3 km (2 mi) east-northeast of Aromas, CA, at 9:04 am PDT on 5 April 2018 (16:04 UTC), less than 1 km deep.
USGS: 3km ENE of Aromas, CA
12 km (8 mi) SSW of Gilroy, CA · 48 km (30 mi) SSE of San Jose, CA
- When
- 9:04 am PDT on 5 April 2018 ()
- Where
- 3 km (2 mi) east-northeast of Aromas, CA · earthquakes near Aromas
- Magnitude
- M 1.6 (md)
- Depth
- -0.1 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Clara County, 37 km N
- Nearest mapped fault
- San Andreas fault, under 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 3135 days ago
Earthquake alerts for Aromas, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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, 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.
Earthquakes near other towns within 30 km: San Juan Bautista, Las Lomas, Pajaro, Interlaken, Watsonville, Gilroy.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
- Around the size people start to feel M 3.0 150× the energy of this one
- This earthquake M 1.6 about 6.4 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 4.6 on 2017-11-13 — about 35,000 times the energy of this one.
Before 2016, the USGS record lists 30 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 28 km WNW of this epicentre
- 6.5 Near Morgan Hill, California · 24 km N of this epicentre
- 6.2 Near San Jose, California · 48 km NNW of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 46 km N of this epicentre
- 6.1 Near San Jose, California · 37 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 36.8972, -121.6145. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Clara County, CA | 37 km (23 mi) | N | earthquakes near Santa Clara County |
| Santa Cruz County, CA | 37 km (23 mi) | WNW | earthquakes near Santa Cruz County |
| San Benito County, CA | 57 km (35 mi) | SE | earthquakes near San Benito County |
| Monterey County, CA | 78 km (48 mi) | SSE | earthquakes near Monterey County |
| Merced County, CA | 86 km (53 mi) | ENE | earthquakes near Merced County |
| Alameda County, CA | 87 km (54 mi) | NNW | earthquakes near Alameda County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
43 earthquakes have been recorded within 50 km since this one.
- 2.0 8km ENE of Gilroy, CA
- 1.7 3km SSW of San Juan Bautista, CA
- 2.3 3km SSW of San Juan Bautista, CA
- 2.3 9km ENE of San Martin, CA
- 2.0 15km N of Morgan Hill, CA
- 3.1 14km N of Morgan Hill, CA
- 1.7 17km SSE of Tres Pinos, CA
- 1.8 4km SSE of San Juan Bautista, CA
- 1.8 5km NNW of Aromas, CA
- 2.0 10km SSW of Ridgemark, CA
- 2.2 10km NNW of Hollister, CA
- 2.6 10km NNW of Hollister, CA
- 1.8 5km SSW of Gilroy, CA
- 1.9 3km S of San Juan Bautista, CA
- 1.9 4km ESE of Aromas, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.