Report on Pagan (United States) — September 1983
Scientific Event Alert Network Bulletin, vol. 8, no. 9 (September 1983)
Managing Editor: Lindsay McClelland.
Pagan (United States) Small plume emitted
Please cite this report as:
Global Volcanism Program, 1983. Report on Pagan (United States) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 8:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198309-284170.
18.13°N, 145.8°E; summit elev. 570 m
All times are local (unless otherwise noted)
On 8 and 9 September USN personnel observed the volcano during pilot-navigation training flights. They described (and photographed) a plume containing a little ash that issued gently from the crater. Although heavy rain, lightning and convective weather cloud activity to more than 9 km obscured the view on the 8th, the plume was seen rising to 3.4 km. A stratus layer extended 30-35 km ENE at 2-2.5 km altitude. In clear conditions on the 9th, the rising plume and the stratus layer were again observed.
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: Lt. Cmdr. R. Adkerson, COMNAVMARIANAS.