quarry blast · reviewed by a seismologist
M 1.7md
Earthquake near Aromas, CA
No earthquake was likely felt in Aromas in the 24 hours to 5:58 am PST (13:58 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
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.7 quarry blast was recorded 2 km (1 mi) north-northwest of Aromas, CA, at 11:42 am PDT on 1 July 2019 (18:42 UTC), less than 1 km deep.
USGS: 2km NNW of Aromas, CA
11 km (7 mi) E of Watsonville, CA · 46 km (28 mi) SSE of San Jose, CA
- When
- 11:42 am PDT on 1 July 2019 ()
- Where
- 2 km (1 mi) north-northwest of Aromas, CA · earthquakes near Aromas
- Magnitude
- M 1.7 (md)
- Depth
- -0.1 km below the surface
- Felt
- no reports yet
- Nearest
- Santa Cruz County, 34 km WNW
- Nearest mapped fault
- San Andreas fault, 3 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 2690 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 12 km (7 mi) from the epicentre. In Aromas, 2 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 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 100× the energy of this one
- This earthquake M 1.7 about 9.3 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 24,000 times the energy of this one.
Before 2016, the USGS record lists 31 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1989 Loma Prieta, California Earthquake · 25 km NW of this epicentre
- 6.5 Near Morgan Hill, California · 23 km N of this epicentre
- 6.2 Near San Jose, California · 46 km NNW of this epicentre
- 6.2 The 1984 Morgan Hill, California Earthquake · 45 km N of this epicentre
- 6.1 Near San Jose, California · 35 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 36.9062, -121.6535. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Santa Cruz County, CA | 34 km (21 mi) | WNW | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 35 km (22 mi) | N | earthquakes near Santa Clara County |
| San Benito County, CA | 60 km (37 mi) | ESE | earthquakes near San Benito County |
| Monterey County, CA | 80 km (50 mi) | SSE | earthquakes near Monterey County |
| San Mateo County, CA | 85 km (53 mi) | NW | earthquakes near San Mateo County |
| Alameda County, CA | 86 km (53 mi) | NNW | earthquakes near Alameda County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
39 earthquakes have been recorded within 50 km since this one.
- 1.9 1km ENE of Tres Pinos, CA
- 1.6 16km NW of Pinnacles, CA
- 2.0 10km SSW of Ridgemark, CA
- 2.0 2km WSW of San Juan Bautista, CA
- 1.6 16km SSE of Tres Pinos, CA
- 1.5 3km E of Aromas, CA
- 1.8 12km S of Tres Pinos, CA
- 1.6 11km S of Tres Pinos, CA
- 1.6 16km NW of Pinnacles, CA
- 1.9 7km ESE of Prunedale, CA
- 2.6 14km N of Morgan Hill, CA
- 2.7 20km E of Alum Rock, CA
- 2.0 2km NNE of Del Monte Forest, CA
- 1.6 6km NNW of Aromas, CA
- 1.6 13km NNW 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
- 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.