Volcano in United States
Semisopochnoi volcano: eruption status today
Updated
No eruption of Semisopochnoi is being reported right now Last eruption: 1964 or later (NOAA NCEI).
Live status of Semisopochnoi: whether it is erupting now, satellite hot spots, earthquakes around it, and what an eruption would mean for nearby cities and flights.
- Status now
- No open report
- Last eruption
- 1964 or later
- Elevation
- 1,221 m 4,006 ft
- Type
- Stratovolcano
- Earthquakes within 50 km
- 13 past 30 days (USGS)
- Hot spots within 10 km
- 0 latest NASA FIRMS VIIRS data
- Nearest city
- Petropavlovsk-Kamchatsky 1419 km WNW
Is Semisopochnoi erupting right now?
There is no open NASA EONET event for Semisopochnoi right now. NOAA NCEI dates its most recent eruption to 1964 or later. Volcano observatories can raise alert levels before an eruption starts, so check the national observatory for the current alert level.
No satellite thermal hot spot was detected within 10 km of the summit in the latest NASA FIRMS data, so there is no sign of lava at the surface large enough for VIIRS to see (clouds can hide it).
Earthquakes near Semisopochnoi
USGS located 13 earthquakes within 50 km of Semisopochnoi in the past 30 days, 0 of them in the last week. The largest was M4.4 on Oct 11, 2026, 26 km SSW of the summit at 95 km depth.
6 of them were shallower than 10 km. Swarms of shallow quakes can mean magma or gas is moving, but most swarms end without an eruption; observatories combine them with ground deformation and gas data.
| Time (UTC) | Magnitude | Distance | Depth | Location |
|---|---|---|---|---|
| Oct 18, 11:27 UTC | M1.7 | 30 km S | 82 km | 267 km W of Adak, Alaska |
| Oct 11, 15:32 UTC | M1.1 | 5 km E | 8 km | 256 km W of Adak, Alaska |
| Oct 11, 12:16 UTC | M4.4 | 26 km SSW | 95 km | 275 km W of Adak, Alaska |
| Oct 1, 00:36 UTC | M2.9 | 38 km SSW | 85 km | 272 km W of Adak, Alaska |
| Sep 30, 19:51 UTC | M3.1 | 48 km SE | 99 km | 227 km W of Adak, Alaska |
| Sep 30, 19:10 UTC | M4.3 | 28 km WSW | 118 km | 286 km W of Adak, Alaska |
| Sep 29, 06:41 UTC | M1.1 | 1 km SE | 7 km | 260 km W of Adak, Alaska |
| Sep 29, 01:28 UTC | M2.7 | 48 km SW | 81 km | Rat Islands, Aleutian Islands, Alaska |
| Sep 28, 21:54 UTC | M0.7 | 1 km ESE | 5 km | 259 km W of Adak, Alaska |
| Sep 28, 07:35 UTC | M2.7 | 43 km W | 183 km | Rat Islands, Aleutian Islands, Alaska |
| Sep 28, 04:16 UTC | M-0.2 | 5 km NE | 5 km | 256 km W of Adak, Alaska |
| Sep 28, 04:15 UTC | M0.5 | 2 km NNE | 6 km | 259 km W of Adak, Alaska |
| Sep 27, 13:28 UTC | M0.4 | 1 km N | 2 km | 260 km W of Adak, Alaska |
About Semisopochnoi
Semisopochnoi is a stratovolcano in Aleutian Is, United States, rising to 1,221 m (4,006 ft). NOAA NCEI classes its eruptive history as "Historical".
Stratovolcanoes are steep cones built from alternating lava and ash layers; their eruptions are often explosive, with ash columns that can reach cruising altitude.
The volcano is remote: the nearest city in our list is Petropavlovsk-Kamchatsky, 1419 km away.
Flights and volcanic ash
No major hub airport is within 400 km (the closest is Ted Stevens Anchorage, 2102 km away), but ash clouds from explosive eruptions can drift for thousands of kilometres along flight routes.
Volcanic Ash Advisory Centres (VAACs) issue the official ash advisories that airlines and air traffic control follow.
Other volcanoes in United States
United States has 58 volcanoes on this site that erupted since 1900 or are active now, 2 of them with an open NASA activity report today. The closest other one is Gareloi, 113 km away.
Nearby volcanoes
Volcanoes in United States
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Data: NOAA NCEI Volcano Locations, NASA EONET (open volcano events), USGS earthquakes, NASA FIRMS (VIIRS hot spots), Smithsonian Global Volcanism Program.