Volcanic Eruption at Ahyi Seamount
Right now
The most recent data we hold from USGS arrived 6 hours 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 one of only 4 we have recorded within 20 km of this point since 23 July 2026. The last comparable one was on 24 September 2026. 2 more were recorded here in the fortnight before it.
What the source measured
USGS reported: NMI Ahyi Seamount YELLOW/ADVISORY - No plumes seen in satellite images; no significant geophysical signals.
USGS moved the alert level from UNASSIGNED to ADVISORY.
Nearby, since 23 July 2026
- September 24, 2026 · score 18 · 0.0 km
- September 18, 2026 · score 18 · 0.0 km
- September 10, 2026 · score 18 · 0.0 km
How we know
One source: USGS. Not yet confirmed by a second, independent source.
Our own score for this event is 18 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 | Volcanic Eruption |
| Severity | Medium |
| Calamity Score (ours) | 18 / 100 |
| Legacy data-support index | 0.62/1 |
| Coordinates | 20.4370, 145.0300 |
| Nearest City | Saipan (586 km) |
| Urban exposure index (PEI) | 0 within 100 km |
| Impact Tier | minor |
| Timestamp | 2026-10-01T20:39:46.000Z |
| Source | https://volcanoes.usgs.gov/hans2/view/notice/DOI-USGS-NMI-2026-10-01T20:37:33+00:00 |
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_volcano. Occurrence: 2026-10-01T20:39:46.000Z.
First archived: 2026-09-25T11:56:34.807Z. Material modification: 2026-10-01T21:00:25.974Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
1 retained revision changed source fields this page does not show; the index, severity and version stayed the same.
Score Breakdown
Technical Details
| VolcanoName | Ahyi Seamount |
| VolcanoId | 284141 |
| AlertLevel | ADVISORY |
| ColorCode | YELLOW |
| ObservatoryCode | nmi |
| NvewsThreat | Very Low Threat |
| PreviousAlertLevel | UNASSIGNED |
| PreviousColorCode | UNASSIGNED |
Safety Information
During volcanic activity: follow evacuation orders from authorities. Volcanic ash can damage lungs — wear N95 masks or wet cloth over nose and mouth. Stay indoors during ashfall, close windows, and avoid driving. Lahars and pyroclastic flows can travel at high speeds — stay away from valleys and river channels near the volcano.
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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