Report on Martin (United States) — 11 January-17 January 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 11 January-17 January 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Martin (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 11 January-17 January 2006. Smithsonian Institution and US Geological Survey.
58.172°N, 155.361°W; summit elev. 1863 m
All times are local (unless otherwise noted)
Increased seismicity occurred at Martin during 8 January until at least 15 January. About 300 earthquakes were recorded during 2 days, in contrast to the background rate of ~25 earthquakes per month since the seismic network was installed in 1996. AVO increased the Concern Color Code to Yellow. AVO reported that swarms of earthquakes of this nature are common at volcanoes such as Martin, and do not suggest that eruptive activity is imminent. Satellite data showed nothing unusual, although steaming is frequently observed at the volcano.
Geologic Background. The mostly ice-covered Mount Martin stratovolcano lies at the SW end of the Katmai volcano cluster in Katmai National Park. The volcano was named for George C. Martin, the first person to visit and describe the area after the 1912 eruption. It is capped by a 300-m-wide summit crater, which is ice-free because of an almost-constant steam plume and contains a shallow acidic lake. The edifice overlies glaciated lava flows of the adjacent mid- to late-Pleistocene Alagoshak volcano on the WSW and was constructed entirely during the Holocene. Martin consists of a small fragmental cone that was the source of ten thick overlapping blocky dacitic lava flows, largely uneroded by glaciers, that descend 10 km to the NW, cover 31 km2, and form about 95% of the eruptive volume of the volcano. Two reports of historical eruptions that originated from uncertain sources were attributed by Muller et al. (1954) to Martin.