Available Weekly Reports
There are no activity reports for Umboi.
There are no eruptions known for Umboi.
Umboi Island, 50 km in its longest dimension, is the largest of the volcanic islands off the north coast of New Guinea. Dominantly basaltic-andesitic Umboi is comprised of several coalescing stratovolcanoes that are cut by a large 13 x 17 km caldera whose walls rise up to 1 km above its floor. The caldera is widely breached to the sea on the NE side and contains three youthful post-caldera cones with summit crater lakes, Talo, Soal, and Barik. The largest of these cones, 1494-m-high Talo, displays several thermal areas and has satellitic cones on its flanks. No historical eruptions have been reported at Umboi, but activity of the post-caldera cones is thought to have continued until the last few hundred years (Johnson et al., 1972).