Earthquake · automatic estimate, may change
M 1.6md
Earthquake near San Carlos, CA
No earthquake was likely felt in San Carlos in the 24 hours to 7:18 pm PST (03:18 UTC). The last one was M 2.7, 23 km (14 mi) NW, at 5:17 pm PDT on 28 October 2026, estimated intensity II (weak) in town; 526 felt reports to USGS. Every earthquake near San Carlos
This page: a magnitude 1.6 earthquake was recorded 3 km (2 mi) west-southwest of San Carlos, CA, at 4:57 am PDT on 30 September 2025 (11:57 UTC), less than 1 km deep. The magnitude and location are an automatic first estimate and may change.
USGS: 3 km WSW of San Carlos, CA
7 km (5 mi) WSW of Redwood City, CA · 34 km (21 mi) SSE of San Francisco, CA
- When
- 4:57 am PDT on 30 September 2025 ()
- Where
- 3 km (2 mi) west-southwest of San Carlos, CA · earthquakes near San Carlos
- Magnitude
- M 1.6 (md)
- Depth
- 0.8 km below the surface
- Felt
- no reports yet
- Nearest
- San Mateo County, 11 km SW
- Nearest mapped fault
- San Andreas fault, 2 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 409 days ago
Earthquake alerts for San Carlos, 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 11 km (7 mi) from the epicentre. In San Carlos, 3 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: San Carlos 3 km, intensity II · Belmont 3 km, intensity II · Redwood City 5 km, intensity II · Foster City 8 km, intensity II · San Mateo 8 km, intensity II · Menlo Park 11 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 7.6 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 2,000,000× 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 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 4.4 on 2018-01-04 — about 15,000 times the energy of this one.
Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:
- 7.9 The 1906 San Francisco, California Earthquake · 36 km NW of this epicentre
- 6.2 Near San Jose, California · 49 km ESE of this epicentre
- 5.8 7 km NNW of Boulder Creek, California · 36 km SSE of this epicentre
- 5.5 Santa Cruz Mountains, California · 44 km SE of this epicentre
- 5.5 6 km NNE of East Foothills, California · 46 km E 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 37.4928, -122.2933. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Mateo County, CA | 11 km (7 mi) | SW | earthquakes near San Mateo County |
| Alameda County, CA | 38 km (23 mi) | ENE | earthquakes near Alameda County |
| Contra Costa County, CA | 56 km (35 mi) | NNE | earthquakes near Contra Costa County |
| Santa Cruz County, CA | 59 km (37 mi) | SSE | earthquakes near Santa Cruz County |
| Santa Clara County, CA | 61 km (38 mi) | ESE | earthquakes near Santa Clara County |
| San Francisco County, CA | 70 km (44 mi) | WNW | earthquakes near San Francisco County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 1.5 4 km SE of San Ramon, CA
- 1.6 4 km SE of San Ramon, CA
- 2.3 3 km SE of San Ramon, CA
- 1.7 4 km SE of San Ramon, CA
- 1.7 4 km SE of San Ramon, CA
- 1.6 4 km ESE of San Ramon, CA
- 2.1 4 km SE of San Ramon, CA
- 1.6 4 km SE of San Ramon, CA
- 1.9 4 km SE of San Ramon, CA
- 1.6 3 km SE of San Ramon, CA
- 2.3 3 km SE of San Ramon, CA
- 3.0 4 km SE of San Ramon, CA
- 2.9 4 km SE of San Ramon, CA
- 2.3 4 km SE of San Ramon, CA
- 3.0 4 km SE of San Ramon, 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.