quarry blast · reviewed by a seismologist
M 1.9md
Earthquake near Thermalito, CA
No earthquake was likely felt in Thermalito in the 24 hours to 3:42 am PST (11:42 UTC). The last one was M 5.6, 142 km (88 mi) W, at 8:10 am PDT on 24 June 2026, estimated intensity III (weak) in town; 5,311 felt reports to USGS. Every earthquake near Thermalito
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.9 quarry blast was recorded 10 km (6 mi) north of Thermalito, CA, at 11:59 am PDT on 13 August 2019 (18:59 UTC), less than 1 km deep.
USGS: 10km N of Thermalito, CA
26 km (16 mi) SE of Chico, CA · 115 km (72 mi) N of Sacramento, CA
- When
- 11:59 am PDT on 13 August 2019 ()
- Where
- 10 km (6 mi) north of Thermalito, CA · earthquakes near Thermalito
- Magnitude
- M 1.9 (md)
- Depth
- -0.2 km below the surface
- Felt
- no reports yet
- Nearest
- Butte County, 7 km N
- Nearest mapped fault
- Foothills fault system, 14 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 2648 days ago
Earthquake alerts for Thermalito, 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 14 km (9 mi) from the epicentre. In Thermalito, 10 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: Oroville, Oroville East, South Oroville, Berry Creek, Paradise, Durham.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 810,000× the energy of this one
- Magna, Utah 2020 M 5.7 580,000× the energy of this one
- Around the size people start to feel M 3.0 51× the energy of this one
- This earthquake M 1.9 about 19 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 3 earthquakes of M5 or more within 50 km:
- 5.7 The 1975 Oroville, California Earthquake · 19 km SSE of this epicentre
- 5.2 4 km E of Palermo, California · 20 km SSE of this epicentre
- 5.1 5 km ENE of Palermo, California · 19 km SSE 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 39.5995, -121.5900. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Butte County, CA | 7 km (5 mi) | N | earthquakes near Butte County |
| Yuba County, CA | 42 km (26 mi) | SSE | earthquakes near Yuba County |
| Sutter County, CA | 63 km (39 mi) | S | earthquakes near Sutter County |
| Glenn County, CA | 70 km (43 mi) | W | earthquakes near Glenn County |
| Colusa County, CA | 73 km (45 mi) | SW | earthquakes near Colusa County |
| Nevada County, CA | 78 km (48 mi) | ESE | earthquakes near Nevada County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
57 earthquakes have been recorded within 50 km since this one.
- 2.3 5km NNE of Hamilton City, CA
- 1.9 4km NE of Hamilton City, CA
- 2.1 9km ENE of Loma Rica, CA
- 2.1 15km ESE of Willows, CA
- 1.8 4km NE of Hamilton City, CA
- 2.1 4km NE of Hamilton City, CA
- 1.6 10km E of Loma Rica, CA
- 2.2 13km WSW of Durham, CA
- 1.7 3km NNE of Hamilton City, CA
- 1.7 4km NNE of Hamilton City, CA
- 2.6 13km WSW of Durham, CA
- 1.9 10km ENE of Loma Rica, CA
- 2.8 4km N of Hamilton City, CA
- 1.6 17km WSW of Durham, CA
- 1.7 10km N of Thermalito, 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.