Right now
The most recent data we hold from USGS arrived 1 minute ago, and this point is in it.
Nothing else has been detected within 20 km in the last 24 hours.
Reported by USGS today.
It is the only one we have recorded within 20 km of this point since 20 March 2026. The last comparable one was on 29 August 2026.
What the source measured
USGS reported: 97 km W of Petrolia, CA
USGS recorded magnitude 4.8 at a depth of 10 km.
Nearby, since 20 March 2026
- March 20, 2026 · 0.8 km
- March 20, 2026 · 0.8 km
- August 29, 2026 · 1.3 km
How we know
4 recorded sources include USGS; independence is not established by this count.
Our own score for this event is 7 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v5. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Earthquake |
| Severity | Low |
| Calamity Score (ours) | 7 / 100 |
| Legacy data-support index | 0.72/1 |
| Coordinates | 40.4225, -125.4183 |
| Nearest City | Eureka (114 km) |
| Urban exposure index (PEI) | 0 within 30 km |
| Impact Tier | minor |
| Timestamp | 2026-09-29T11:36:39.240Z |
| Source | https://earthquake.usgs.gov/earthquakes/eventpage/nc75444322 |
Physical priority index · v5. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: usgs. Occurrence: 2026-09-29T11:36:39.240Z.
First archived: 2026-09-29T11:45:55.716Z. Material modification: 2026-09-29T20:14:32.511Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
20 retained revisions changed source fields this page does not show; the index, severity and version stayed the same.
Score Breakdown
Technical Details
| Mag | 4.77 |
| Depth | 10 |
| Tsunami | false |
| Felt | 16 |
| Mmi | 2.27 |
| Alert | green |
| Sig | 354 |
| Emsc Mag | 4.8 |
| Emsc Depth | 14 |
| Emsc MagType | mw |
| Emsc Region | OFFSHORE NORTHERN CALIFORNIA |
| Emsc Auth | EMSC |
| Emsc SourceId | 2067049 |
| Gfz Mag | 4.68 |
| Gfz Depth | 10 |
| Gfz MagType | mb |
| Gfz Region | Off Coast of Northern California |
| Ncedc Mag | 4.7 |
| Ncedc Depth | 10 |
| Ncedc MagType | Mw |
Safety Information
If you feel shaking: Drop, Cover, and Hold On. Move away from windows, heavy objects, and exterior walls. After shaking stops, check for injuries and structural damage. Be prepared for aftershocks, which can occur minutes to months after the mainshock. Follow instructions from local emergency management authorities.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
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