Report on Ekarma (Russia) — 25 August-31 August 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 25 August-31 August 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Ekarma (Russia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 August-31 August 2010. Smithsonian Institution and US Geological Survey.
48.958°N, 153.93°E; summit elev. 1170 m
All times are local (unless otherwise noted)
SVERT reported that on 10 August scientists observed a vigorous steam plume from Ekarma that rose to an altitude of 1.8 km (5,900 ft) a.s.l. while visiting Sarychev Peak, 110 km SSW. On 24 August scientists visited Ekarma Island and observed continuous vigorous gas emissions from a new vent located on the S flank, about 250 m below the summit. The flanks had been blanketed by a layer of fine ash with a thickness exceeding 5 cm in the vicinity of the vent. Two recent lahar deposits were seen on the S flank. Based on their observations, SVERT speculated that a small eruption may have occurred between early June and late July 2010. Ekarma does not have a seismic network; satellite image analysis and infrequent ground observations are the primary tool for monitoring many of the Kuril Islands volcanoes.
Geologic Background. The small 5 x 7.5 km island of Ekarma lies 8.5 km N of Shiashkotan Island along an E-W-trending volcanic chain extending westward from the central part of the main Kuril Island arc. It is composed of two overlapping basaltic-andesite to andesitic volcanoes, the western of which has been historically active. Lava flows radiate 3 km in all directions from the summit of the younger cone to the sea, forming a lobate shoreline. A lava dome that was emplaced during the first historical eruption, in 1776-79, forms the peaked summit of the island.