On December 23 at 9:30 am loc. / 18h30 UTC, a third strong explosion shook the Bogoslof.
During the episode, a Coast Guards vessel witnessed ash emissions, lightning, and ejection of lava and fragmentary material for about an hour.
The ash was taken to the Bering Sea under 30,000 feet.
The seismicity continues, but the perceived signals are affected by a strong storm on the Aleutians.
The aviation alert level has returned to red on 23.12 / 20.12. (Vona)
The Bogoslof is not under surveillance of the local geophysical network, which limits the forecast and does not allow a monitoring of the volcanic activity. Only the seismic network, the infrasound sensors of Unalaska, and the satellites, allow control.
Bogoslof - oblique model of the location of Gogoslof in relation to the main Aleutian arc - click to enlarge - image Chris Waythomas, USGS-AVO / 12.2011
Bogoslf constitutes, with Fire Island, the two summits emerged from a large submarine stratovolcano, situated just north of the main front of the volcanic arc of the Aleutians. Some low-lying islands complete the picture.
Eight historical eruptions have been documented in Bogoslof; The most recent, from 6 to 24 July 1992, is marked by the emergence of a lava dome at the northern tip of the island.
Sources: AVO & VONA