Fourpeaked Glacier, Shelikof Strait


Fourpeaked Glacier, Shelikof Strait

by | Feb 12, 2021

Fourpeaked Glacier covers much of Fourpeaked Mountain in Katmai National Park and Preserve, about 90 miles (145 km)  southwest of Homer and 77 miles (124 km) northwest of Kodiak, Alaska. The glacier terminates in a lake about 2.5 miles (4 km) across, and drained by a river that flows for 0.8 miles (1.3 km) to Shelikof Strait. The descriptive name was translated by George Davidson of the U.S. Coast and Geodetic Survey in 1869 from the Russian “Gora Chetyrekhglavaya” meaning “mountain of four heads”.

Fourpeaked volcano is an active stratovolcano that erupted on September 17, 2006, after being dormant for over 10,000 years. At the time, Fourpeaked was an unmonitored volcano with no recent known activity based on limited fieldwork. Airborne gas sampling began within days of the eruption and a network of seismic instruments was installed. Vigorous steaming continued for months, however, there were no further eruptions. The initial eruption was followed by several months of sustained seismic activity and sulfur dioxide emissions exceeding a 1000 tons per day. Fourpeaked volcano remained active for several months and by early 2007 declining seismicity and gas emissions signaled an end to the event.

Fourpeaked Glacier drains east from Fourpeaked Mountain. In 1951, the glacier likely became buoyant when it came off its terminal moraine. This resulted in a  dramatic retreat of 312 feet (95 m) per year between 1951 and 1986. Satellite images from 1981 indicate that much of the glacial lake was filled with ice, but much of this was floating icebergs detached from the glacier. By 2000, the ice floating in the lake was gone, and the glacier terminus had retreated into a narrower inlet. The terminus retreated 1.2 miles (1.9 km) from 1986 to 2014, a rate of 223 feet (68 m) per year. This glacier behaves like other glaciers in Southcentral Alaska where 19 of 20 glaciers are retreating, and the retreating terminus led to the formation and expansion of a large proglacial lake. Read more here and here. Explore more of Fourpeaked Glacier here:

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