Report on Bogoslof (United States) — 29 March-4 April 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 29 March-4 April 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, 29 March-4 April 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 no significant volcanic activity at Bogoslof was detected in seismic or infrasound data during 29 March-4 April, and satellite views were often obscured by clouds or showed nothing noteworthy. Weakly elevated surface temperatures were identified in satellite images during 28-29 March. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.
Geologic Background. 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.