Makushin Volcano | John Seach


Aleutian Islands, Alaska

53.90 N, 166.93 W
summit elevation 2036 m

Makushin volcano is located on northern Unalaska Island in eastern Aleutians. The volcano is separated from the towns of Dutch Harbor and Unalaska by the waters of 10-kilometer-wide Unalaska Bay.

The summit of Makushin is a broad, flat, ice-filled caldera about 4 kilometers in diameter. Numerous glaciers descend from the summit caldera to elevations of 300 to 600 meters above sea level on all sides of the volcano.

The area surrounding Makushin is one of the few localities in the Aleutian Islands where a large population live and work near an active volcano. Explosive eruptions of Makushin Volcano have occurred at least 17 times since the late 1700s.

Caldera-forming eruptions produced pyroclastic flow deposits 100 m deep, which fill valleys on the east, northeast, north, and west of the volcano.

Small maars and cinder cones are aligned along a fault on the north side of the volcano. A large lava flow (Lava Ramp), covers over 50 sq km on the northeast flank of the volcano. A subsidiary cone (Pakushin Cone) is located in the south. Hot springs and fumaroles are found at the summit and in valleys on the east and southeast sides of the volcano.

1995 Eruption
Makushin volcano erupted in January 1995 and produced ash to 2.5 km altitude.

1987 Eruption
An eruption plume was visible rising 900 m above the volcano on 2nd March 1987.

1980 Eruption
In mid 1980 a small eruption occurred from a vent located 60 m below the summit on the south flank.

Makushin Volcano Eruptions

1995, 1987, 1980, 1952?, 1951, 1938, 1926, 1912?, 1907, 1883, 1867?, 1865, 1844?, 1826-38?, 1818?, 1802, 1792?, 1790?, 1768-69