Report on Bogoslof (United States) — 6 September-12 September 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
6 September-12 September 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Bogoslof (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 6 September-12 September 2017. Smithsonian Institution and US Geological Survey.
53.93°N, 168.03°W; summit elev. 150 m
All times are local (unless otherwise noted)
AVO reported that during 6-12 September nothing significant was observed in mostly cloudy satellite images of Bogoslof, and no activity was detected in seismic or infrasound data. The 8 September report noted that the crater lake had been bisected by a narrow isthmus of land. Elevated surface temperatures were identified in one satellite image during 10-11 September. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Geological Summary. Bogoslof is the emergent summit of a submarine volcano that lies 40 km north of the main Aleutian arc. It rises 1500 m above the Bering Sea floor. Repeated construction and destruction of lava domes at different locations during historical time has greatly modified the appearance of this "Jack-in-the-Box" volcano and has introduced a confusing nomenclature applied during frequent visits of exploring expeditions. The present triangular-shaped, 0.75 x 2 km island consists of remnants of lava domes emplaced from 1796 to 1992. Castle Rock (Old Bogoslof) is a steep-sided pinnacle that is a remnant of a spine from the 1796 eruption. Fire Island (New Bogoslof), a small island located about 600 m NW of Bogoslof Island, is a remnant of a lava dome that was formed in 1883.