quarry blast · reviewed by a seismologist
M 1.5md
Earthquake near Atascadero, CA
No earthquake was likely felt in Atascadero in the 24 hours to 7:43 am PST (15:43 UTC). The last one was M 2.1, 8 km (5 mi) SW, at 6:08 am PDT on 21 October 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Atascadero
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.5 quarry blast was recorded 6 km (4 mi) east of Atascadero, CA, at 2:18 pm PDT on 19 July 2019 (21:18 UTC), less than 1 km deep.
USGS: 6km E of Atascadero, CA
- When
- 2:18 pm PDT on 19 July 2019 ()
- Where
- 6 km (4 mi) east of Atascadero, CA · earthquakes near Atascadero
- Magnitude
- M 1.5 (md)
- Depth
- -0.4 km below the surface
- Felt
- no reports yet
- Nearest
- San Luis Obispo County, 17 km SE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2673 days ago
Earthquake alerts for Atascadero, 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 10 km (6 mi) from the epicentre. In Atascadero, 6 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: Atascadero 6 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 5.9 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 2,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
- Around the size people start to feel M 3.0 160× the energy of this one
- This earthquake M 1.5 about 5.9 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:
- 6.5 1922 Parkfield, California Earthquake · 43 km NE of this epicentre
- 6.0 2004 Parkfield, California Earthquake · 43 km NNE of this epicentre
- 5.8 1934 Parkfield, California Earthquake · 41 km N of this epicentre
- 5.5 1966 Parkfield, California Earthquake · 44 km NE of this epicentre
- 5.1 13km N of San Miguel, CA · 44 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 35.4823, -120.5995. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Luis Obispo County, CA | 17 km (11 mi) | SE | earthquakes near San Luis Obispo County |
| Kings County, CA | 96 km (60 mi) | NE | earthquakes near Kings County |
| Monterey County, CA | 106 km (66 mi) | NW | earthquakes near Monterey County |
| Santa Barbara County, CA | 117 km (73 mi) | SSE | earthquakes near Santa Barbara County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
49 earthquakes have been recorded within 50 km since this one.
- 2.0 13km W of Templeton, CA
- 1.6 11km WNW of Templeton, CA
- 2.9 10km W of Templeton, CA
- 1.8 11km NNE of Cayucos, CA
- 1.8 21km WNW of Simmler, CA
- 1.6 8km W of San Luis Obispo, CA
- 2.0 13km NE of San Simeon, CA
- 1.5 8km ESE of San Luis Obispo, CA
- 1.8 11km NNE of Cayucos, CA
- 1.5 9km NNW of Cholame, CA
- 1.5 6km W of Templeton, CA
- 1.6 13km ENE of Cambria, CA
- 1.7 5km W of Paso Robles, CA
- 4.3 11km NNW of Cholame, CA
- 2.1 11km N of Cambria, 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.