Earthquakes 1 km SE of Boulder Creek, CA — Moderate shaking (MMI 5.7)
Reported by USGS 173 days ago.
What the source measured
USGS reported: 1 km SE of Boulder Creek, CA — Moderate shaking (MMI 5.7)
USGS recorded magnitude 4.6 at a depth of 10 km.
How we know
One source: USGS. Not yet confirmed by a second, independent source.
Our own score for this event is 5 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 v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Earthquakes |
| Severity | Low |
| Calamity Score (ours) | 5 / 100 |
| Legacy data-support index | 0.55/1 |
| Coordinates | 37.1157, -122.1125 |
| Timestamp | 2026-04-02T08:41:25.520Z |
| Source | https://earthquake.usgs.gov/earthquakes/eventpage/nc75337442/shakemap |
Physical priority index · v1. 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_shakemap. Occurrence: 2026-04-02T08:41:25.520Z.
First archived: 2026-04-02T19:35:00.430Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Mag | 4.59 |
| Depth | 10.43 |
| Mmi | 5.68 |
| MmiDescription | Moderate |
| Felt | 31869 |
| Alert | green |
| Sig | 904 |
| Tsunami | false |
| Place | 1 km SE of Boulder Creek, CA |
| Types | ,dyfi,event-sequence,focal-mechanism,ground-failure,losspager,moment-tensor,nearby-cities,oaf,origin,phase-data,scitech-link,shake-alert,shakemap, |
| Usgs Dyfi Mag | 4.59 |
| Usgs Dyfi Depth | 10.43 |
| Usgs Dyfi Felt | 31869 |
| Usgs Dyfi Cdi | 5.8 |
| Usgs Dyfi CdiDescription | Moderate |
| Usgs Dyfi Mmi | 5.68 |
| Usgs Dyfi Alert | green |
| Usgs Dyfi Sig | 904 |
| Usgs Dyfi Tsunami | false |
| Usgs Dyfi Place | 1 km SE of Boulder Creek, CA |
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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