Report on Pagan (United States) — August 1983
Scientific Event Alert Network Bulletin, vol. 8, no. 8 (August 1983)
Managing Editor: Lindsay McClelland.
Pagan (United States) Ash cloud seen from aircraft
Please cite this report as:
Global Volcanism Program, 1983. Report on Pagan (United States). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 8:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198308-284170.
18.13°N, 145.8°E; summit elev. 570 m
All times are local (unless otherwise noted)
On 1 September, personnel aboard a Continental Air Micronesia aircraft flying from Saipan to Japan reported "ash and smoke" at an altitude of 6 km within 15 km of the volcano. Scheduled flights pass directly over Pagan Island 1-2 times per day, but no subsequent flights reported increased activity. No eruption clouds were observed on satellite imagery.
Technicians visited Pagan in late July, and saw only minor activity. Inspection of a checkpoint near the volcano on 29 July revealed no indication of major new ashfall since geologists left the island in mid-March. Pagan Island remains uninhabited, as it has since the major eruption of May 1981 (6:4-5), although residents and officials occasionally visit the island. Pagan's mayor, on the island through late August, observed no change from the low-level late July activity.
Geologic Background. Pagan Island, the largest and one of the most active of the Mariana Islands volcanoes, consists of two stratovolcanoes connected by a narrow isthmus. Both North and South Pagan stratovolcanoes were constructed within calderas, 7 and 4 km in diameter, respectively. The 570-m-high Mount Pagan at the NE end of the island rises above the flat floor of the northern caldera, which may have formed less than 1000 years ago. South Pagan is a 548-m-high stratovolcano with an elongated summit containing four distinct craters. Almost all of the historical eruptions of Pagan, which date back to the 17th century, have originated from North Pagan volcano. The largest eruption of Pagan during historical time took place in 1981 and prompted the evacuation of the sparsely populated island.
Information Contacts: R. Shaw, IATA, Montreal; R. Koyanagi, HVO; F. Chong, Disaster Control Officer, Saipan; O. Karst, NOAA/NESDIS.