The Shishaldin Volcano in Alaska's Aleutian Islands, which began erupting on July 11, 2023, has shown decreased activity, according to the Alaska Volcano Observatory. While low-level ash emissions persist below 10,000 feet, a significant ash plume that reached 30,000 feet on Tuesday morning has dissipated. This plume was visible hundreds of miles from the volcano, prompting the National Weather Service to issue a SIGMET (Significant Meteorological Information) warning for aircraft.
Following the decline in eruptive activity, both the aviation alert and Volcano Alert Levels have been lowered. Located approximately 700 miles southwest of Anchorage, Shishaldin Volcano sits near the center of Unimak Island, home to a small community of around 65 residents in False Pass, northeast of the volcano.
The eruption, which commenced on July 11, initially displayed significantly elevated surface temperatures at the summit. A U.S. Coast Guard helicopter observed the eruptive activity the following day. A notable explosion on Friday generated an ash cloud reaching 7.5 miles high, drifting southward over the Pacific, followed by a smaller explosion later that day.
Shishaldin, a highly active volcano in the Aleutian arc, is a symmetrical cone with a base diameter of 10 miles. Its 660-foot crater frequently emits steam and occasionally ash. Historical records indicate at least 26 confirmed eruptions since 1824, with varying intensities. A notable eruption in 1999 produced an ash cloud reaching 8.5 miles high.
