Ash eruption to 2,500 m altitude

On 19 August, U.S. Coast Guard observers reported that Pyre Peak . . . was continuing to erupt from a vent ~180 m below the summit. A dark ash plume over the volcano that day reached an altitude of 2,500 m and drifted ESE. No reports of ashfall in the sparsely populated region were received. U.S. Coast Guard observers reported that Pyre Peak was continuing to erupt in late August, but poor weather conditions prevented observers from confirming continued activity through 3 September. Frequent poor weather and limited air traffic combine to make tracking of activity at this remote island volcano difficult.

Information Contacts: AVO.

Information is preliminary and subject to change. All times are local (unless otherwise noted)

March 1977 (NSEB 02:03) Cite this Report

Lava fountaining from a 1-km-long rift seen on 6 March

Jürgen Kienle reported that on 6 March at about 0400, the crew of the USCG Cutter Mellon observed and photographed eruptive activity at the 750-m level of Pyre Peak, Seguam Island. Eight lava fountains rising to an estimated 90 m were observed along a l-km radial rift 2.5 km SW of Pyre Peak summit. Activity appeared to be progressing NE (towards the summit).

A lava flow formed and divided into two tongues. The larger was approximately 2.5 km long and l km wide. The smaller moved toward the S, and was approximately l km long and 0.5 km wide. Three dense black clouds were erupted from the vent during 2 hours of observation, after which the Mellon departed.

The nearest short-period seismometers, 225 km to the E (Nikolski), and 300 km to the W (Adak), were too far away to register any unusual earthquake activity.

Thomas Miller reported that on 8 March, a Reeve Aleutian Airlines flight passed over Seguam at low altitude. The pilot reported that lava effusion and fountaining had ended, but that a considerable amount of steam, possibly containing some ash, was being emitted from the fissure. Lava flows had not reached the sea. Poor weather during much of the year hampers aerial observation.

Several other ship reports of eruptions in the area have been received in the past several years. Seguam is uninhabited.

Information Contacts: J. Kienle, Univ. of Alaska; T. Miller, USGS, Anchorage.

December 1992 (BGVN 17:12) Cite this Report

Small ash eruptions

Small ash eruptions from a satellite cone 1.5 km S of the W caldera's central cone (Pyre Peak) (figure 1) were observed on 27 and 30 December 1992 by the U.S. Coast Guard . . . . Activity on the 27th consisted of an ash plume that extended 24 km N from the island at 1,200 m altitude. On 30 December, discrete explosions ejected ash to several hundred meters height. Ash fell S of the vent, which appears to be located near the N end of a line of lava fountains observed during the 1977 eruption. The vent site consists of a cluster of cinder cones and craters, which was probably the source of a prehistoric basaltic lava field covering ~21 km².

Figure 1. Topographic map of Seguam Island showing the area of December 1992 activity (dot S of Pyre Peak). The line SE from the vent site represents the 1977 lava fountains, and the outline shows the 1977 lava flows. Courtesy of AVO.

Information Contacts: Michael Doukas, USGS Anchorage.

May 1993 (BGVN 18:05) Cite this Report

Ash eruptions reported

A small ash burst, rising through clouds near Pyre Peak, was reported by the U.S. Coast Guard on 28 May. A plume to 3 km altitude was reported on 2 June by the NWS, but it is not known if the plume contained ash.

Information Contacts: AVO.

July 1993 (BGVN 18:07) Cite this Report

Ash eruptions to 2,400 m height; lava flow

Heavy ash eruptions rising 900-1,200 m were reported the morning of 31 July by the U.S. Coast Guard. A lava flow was also noted. According to these observers, the volcano was still erupting sporadically on 10 August, with light- to dark-gray ash plumes rising 2,400 m above the summit. Reports from Atka Island (~110 km W) indicate that weather conditions have frequently prevented observations.

Information Contacts: AVO.

August 1993 (BGVN 18:08) Cite this Report

Ash eruption to 2,500 m altitude

On 19 August, U.S. Coast Guard observers reported that Pyre Peak . . . was continuing to erupt from a vent ~180 m below the summit. A dark ash plume over the volcano that day reached an altitude of 2,500 m and drifted ESE. No reports of ashfall in the sparsely populated region were received. U.S. Coast Guard observers reported that Pyre Peak was continuing to erupt in late August, but poor weather conditions prevented observers from confirming continued activity through 3 September. Frequent poor weather and limited air traffic combine to make tracking of activity at this remote island volcano difficult.

Information Contacts: AVO.