quarry blast · reviewed by a seismologist
M 0.9ml
Earthquake near La Mesa, CA
No earthquake was likely felt in La Mesa in the 24 hours to 4:49 am PST (12:49 UTC). The last one was M 4.9, 177 km (110 mi) ESE, at 10:27 am PST on 3 November 2026, estimated intensity II (weak) in town; 321 felt reports to USGS. Every earthquake near La Mesa
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 0.9 quarry blast was recorded 7 km (5 mi) north-northwest of La Mesa, CA, at 1:13 pm PDT on 7 October 2026 (20:13 UTC), less than 1 km deep.
USGS: 7 km NNW of La Mesa, CA
7 km (5 mi) E of San Diego, CA · 7 km (4 mi) NNW of La Mesa, CA
- When
- 1:13 pm PDT on 7 October 2026 ()
- Where
- 7 km (5 mi) north-northwest of La Mesa, CA · earthquakes near La Mesa
- Magnitude
- M 0.9 (ml)
- Depth
- -0.1 km below the surface
- Felt
- no reports yet
- Nearest
- San Diego County, 34 km NE
- Nearest mapped fault
- Newport-Inglewood-Rose Canyon fault, 15 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 36 days ago
Earthquake alerts for La Mesa, CA
Get a notification in this browser when USGS records an earthquake near La Mesa, CA. No account or email needed.
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 it was probably too small to be felt, even directly above it. 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: Santee, El Cajon, Lemon Grove, Spring Valley, Casa de Oro-Mount Helix, Bostonia.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 0.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 1.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 22,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 15,000,000× the energy of this one
- Around the size people start to feel M 3.0 1,400× the energy of this one
- This earthquake M 0.9 about 0.7 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 5.2 on 2025-04-14 — about 2,800,000 times the energy of this one.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
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 32.8263, -117.0585. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Diego County, CA | 34 km (21 mi) | NE | earthquakes near San Diego County |
| Orange County, CA | 116 km (72 mi) | NW | earthquakes near Orange County |
| Riverside County, CA | 140 km (87 mi) | NE | earthquakes near Riverside County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
24 earthquakes have been recorded within 50 km since this one.
- 1.0 10 km NW of Pine Valley, CA
- 0.6 6 km WSW of Pine Valley, CA
- 1.3 6 km ESE of Bonita, CA
- 1.3 9 km S of Lake Henshaw, CA
- 1.4 4 km E of San Diego, CA
- 0.4 7 km SSE of Lake Henshaw, CA
- 2.4 6 km NW of Pine Valley, CA
- 1.2 6 km NNW of Lakeside, CA
- 0.7 3 km WNW of Julian, CA
- 1.7 21 km WNW of La Jolla, CA
- 1.2 12 km NNW of Pine Valley, CA
- 1.1 9 km NE of Alpine, CA
- 0.7 12 km SSW of Julian, CA
- 1.3 6 km NW of Pine Valley, CA
- 1.1 6 km NW of Pine Valley, 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.
Revisions
USGS refines a solution as more stations report. Every change we have seen is listed here.
| What changed | From | To | When |
|---|---|---|---|
| event type | earthquake | quarry blast | |
| review status | automatic | reviewed | |
| location | 7 km NE of San Diego, CA | 7 km NNW of La Mesa, CA | |
| longitude | -117.09 | -117.06 | |
| latitude | 32.81 | 32.83 | |
| depth | 5.08 | -0.11 | |
| magnitude | 1.22 | 0.91 |
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.