The crew of the ship Blackhawk, (Hap Heyden, Ron Saylor, Dave Weyl and Capt. Emil Lindal) observed eruptive activity . . . on the morning of 27 May. At 0100, while some 30 km E . . . , one of the crew members could see glow at the top of the volcano and smelled sulfur fumes.

From 11 km ESE . . . at about 0235, Heyden observed a crater ~60 m in diameter on the upper ESE flank. The back inside wall of the crater was visible. Lava rose to 30 m above the rim, then fell back into the crater. Weyl saw an ~10-m-wide glowing zone that extended from the crater at least 100 m down the SE flank, probably a lava channel. Glow from the crater seemed to be pulsating substantially. As the Blackhawk headed SW, at about 0450, Saylor detected a fog-like cloud that irritated his eyes and throat. They did not emerge from the fume cloud until they were S of Herbert Island, ~25 km SSW of the volcano. No ash was detected on the boat.

T. Madsen and John Reeder flew within 40 km of Mt. Cleveland on 10 July at about 1845 and 2115, observing minor steaming from the SE summit. Black ash blanketed the upper 650 m of the volcano, while the lower slopes were still covered with white snow.

Geological Summary. The beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Joined to the rest of Chuginadak Island by a low isthmus, Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 it produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.

Information Contacts: J. Reeder, ADGGS.