Bougainville Island, North Solomons Province,
Papua New Guinea
6.092 S, 155.225 E
summit elevation 1544 m
Billy Mitchell volcano is located NE of Bagana volcano. It contains a steep-sided caldera, with a lake. Explosive eruptions from central crater is the typical eruption type.
The upper slopes of the volcano are covered by kunai grass and scattered trees and the lower slopes are covered by tropical rain forest.
The volcano summit is on the crater rim. The smooth eastern flank of the volcano extends 22 km from the crater to the coast. The other sides of the volcano have rough and irregular surfaces.
Billy Mitchell Lake
The summit contains a well formed crater, 2.4 km in diameter, occupied by Lake Billy Mitchell. The lake covers an area of 3 sq km, and has a depth of 90 m. An outflow in the northern caldera rim, leads to the Tekan River.
Eruptions at the volcano are mainly explosive and have produced large amounts of tephra. Ignimbrite from 1580 eruption of Billy Mitchell extends in a broad fan 20 km eastwards towards the Pacific Ocean. The eruption probably formed the caldera. The area covered by the deposit is 300 sq km, and had a volume of 10 cubic km.
The explosive eruption of Baitoushan Volcano in NE China 969 ±20 AD) competes with the Billy Mitchell eruption for the ice core data, therefore conclusive records on the effects on climate are not easily obtained.