Description: From Shackleford (1982): "Observations in early July 1980 at Makushin by personnel from Lamont-Doherty Geological Observatory found a new explosion crater on the central cone within the caldera, some 60 m below the cone's summit. From this new vent tephra (presumably lithic in nature) extended in streaks on the snow's surface to the southeast. Some of the ejected blocks created impact craters 30-60 m from the crater. This minor explosive event was not witnessed, but obviously took place only shortly before the date of observation. It certainly took place within the last year, but Spring 1980 is deemed a likely date for this event. Otherwise, observations in July 1980 found 10 vents liberating steam and H2S on the summit of the central cone."
From Smithsonian Institution (1980): "On 8 July, J. Hauptmann, G. Gunther, and R. [Steuer] visited a seismic station on the E flank and overflew the summit. More than ten roughly circular vents emitted vapor from the summit area, a flat region about 100 m across. The largest vent was about 30 m in diameter, and others were around 10 m across. An H2S odor was detected, but no ash or incandescent material was observed.
"About 60 m below the summit on the S flank, an explosion vent had recently ejected tephra ranging in size from ash to blocks, deposited in streaks aligned roughly toward the SE. Some impact craters were present in the deposit area, which extended 30-60 m from the vent."