Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near Anza, CA
No earthquake was likely felt in Anza in the 24 hours to 2:47 am PST (10:47 UTC). The last one was M 2.6, 17 km (10 mi) S, at 10:44 pm PST on 5 November 2026, estimated intensity II (weak) in town; 7 felt reports to USGS. Every earthquake near Anza
This page: a magnitude 1.6 earthquake was recorded 13 km (8 mi) west of Anza, CA, at 12:10 am PDT on 21 August 2017 (07:10 UTC), 8.3 km deep.
USGS: 13km W of Anza, CA
89 km (56 mi) NNE of San Diego, CA · 25 km (15 mi) SE of Hemet, CA
- When
- 12:10 am PDT on 21 August 2017 ()
- Where
- 13 km (8 mi) west of Anza, CA · earthquakes near Anza
- Magnitude
- M 1.6 (ml)
- Depth
- 8.3 km below the surface
- Felt
- no reports yet
- Nearest
- San Diego County, 61 km S
- Nearest mapped fault
- San Jacinto fault, 10 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 3304 days ago
Earthquake alerts for Anza, CA
Get a notification in this browser when USGS records an earthquake near Anza, 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, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Anza, 13 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: Aguanga, Idyllwild, Valle Vista, Idyllwild-Pine Cove, East Hemet, Hemet.
How big was it?
This earthquake released about 7.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 7.8 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 2016-06-10 — about 230,000 times the energy of this one.
Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 The 1918 San Jacinto, California Earthquake · 26 km NW of this epicentre
- 5.4 20km NNW of Borrego Springs, CA · 36 km ESE of this epicentre
- 5.3 6km SSE of Hemet, CA · 18 km NW of this epicentre
- 5.3 18km ESE of Anza, CA · 31 km ESE of this epicentre
- 5.2 12km WSW of Morongo Valley, CA · 49 km NNE 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 33.5732, -116.8155. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Diego County, CA | 61 km (38 mi) | S | earthquakes near San Diego County |
| Riverside County, CA | 77 km (48 mi) | ENE | earthquakes near Riverside County |
| Orange County, CA | 90 km (56 mi) | W | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
44 earthquakes have been recorded within 50 km since this one.
- 1.5 9km NE of Aguanga, CA
- 2.1 8km NE of Aguanga, CA
- 1.5 7km E of Calimesa, CA
- 2.7 8km NE of Aguanga, CA
- 1.6 9km NE of Aguanga, CA
- 1.9 8km NE of Aguanga, CA
- 1.6 9km NE of Aguanga, CA
- 1.6 7km NW of Banning, CA
- 1.5 9km NE of Aguanga, CA
- 1.6 7km NE of Beaumont, CA
- 3.0 7km NE of Beaumont, CA
- 1.6 9km ESE of Palomar Observatory, CA
- 1.7 9km NE of Aguanga, CA
- 1.6 3km SE of Lake Henshaw, CA
- 3.0 2km SSE of Lake Henshaw, 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.