Last eruption of the Bogoslof the 28.05.2017 / 2h34 PM AKDT, and its plume surmounted by a pileus - photo Dave Schneider AVO
The progressive map work of the AVO shows the evolution both in shape and surface of Bogoslof, before and during the eruption, between December 25, 2016 and end May 2017 after the last important event of the volcano.
Bogoslof - 23.02.2017 - Digital elevation model (DEM) and satellite image - Doc. AVO -USGS / Chris Waythomas
Bogoslof - 31.01.2017 - Digital elevation model (DEM) and satellite image - Doc. AVO -USGS / Chris Waythomas
Bogoslof - morphological changes between March 2015 (before eruption) and 24.01.2017 (after various eruptive episodes) - AVO -USGS / Chris Waythomas
The area of the volcano island rose from 0.288 km² before the eruption to 1.024 km² on May 31, 2017. Just the last eruption of 28.05.2017 made it take 0.152 km².
Bogoslof is the summit of an underwater volcano at 1.500 meters above sea level on the Bering Sea. The phases of successive construction and destruction of lava domes in different places in the course of historical times have altered its appearance. In March 2015, its triangular shape consisted of remains of lava domes installed between 1796 and 1992; Its subaerial portions are composed of fragmentary deposits, agglomerates, lava, remains of domes and beach sediments. All rock samples show a basaltic and andesitic composition with high potassium content.
Sources: AVO - USGS and Global Volcanism Program
Sketch of the island of Bogoslof, showing the dome of 1992 and new flat land just off (labeled "rocks"). Characteristics prior to 1992 are derived from a 1982 John Reeder transit survey which showed a significant erosion of mild pyroclastic deposits from 1926-27 since the USGS mapping in 1947 (Byers, 1959). Courtesy of John Reeder / GVP