Mageik Volcano - John Seach



58.20 N, 155.25 W
summit elevation 2165 m

Mageik volcano is located in Katmai National Park. The volcano contains 4 peaks in a broad summit. The central peak contains a lava dome, and the east, SW, and north volcanoes contain ice-filled craters.

Four ice-mantled summit peaks mark discrete eruptive vents. Each vent is the source of numerous lava flows (56%–68% SiO2), which are up to 50–200 m thick distally.

The southwest summit is the oldest and richer in K2O than those of the other three.

The East Summit is the youngest, and has produced 12 leveed lava flows (60%–64% SiO2) which have descended toward Katmai Pass and Mageik Creek, where terminal lobes are 60–150 m thick.

Ice-filled craters on the North and East Summits are usually obscured by snow, but an ice-free 350 m wide phreatic crater between the East and Central Summits
contains an acid lake and many superheated fumarolic jets.

Holocene debris avalanches from three different locations on the south slopes of Mageik volcano have devastated the forks of Martin Creek. The youngest occurred during the 1912 ash fall from Novarupta, and was probably triggered by seismicity accompanying collapse of Mount Katmai.

Morphology of the crater has not changed since it was first photographed in 1923, and the only tephra deposits younger than 2000 years on the flanks of Mageik are the Novarupta pumice falls of 1912 and Trident ash of 1953–1974.

Mageik Volcano Eruptions

1946?, 1936, 1929?, 1927