The ongoing eruption of a remote volcano in Alaska’s Aleutian Islands produced an ash cloud so large Tuesday that warnings were sent to pilots about dangerous conditions.
An ash cloud with an initial height of about 5.5 miles (8.9 kilometers) was reported after the morning eruption of Shishaldin Volcano. But by early afternoon, ash plumes were below 1.9 miles (3 kilometers), and the aviation alert was downgraded, according to the Alaska Volcano Observatory.
The volcano is about 700 miles (1,127 kilometers) southwest of Anchorage and is located near the middle of Unimak Island. The island’s 65 or so residents live about 25 miles (40 kilometers) northeast of the volcano, in the community of False Pass.
The Shishaldin Volcano began erupting on July 11. A US Coast Guard overflight confirmed lava erupted the same day inside the summit crater.
A significant explosion early Friday created an ash cloud that reached 7.5 miles (12 kilometers) and drifted south into the Pacific Ocean. A second smaller explosion occurred on Friday.
The volcano, one of the most active in the Aleutian arc, saw more lava eruptions after midnight on Tuesday, with no significant ash emissions, the observatory said. That changed hours later in the ash cloud. The National Weather Service issued an advisory due to the drifting ash cloud.
Volcanic ash is angular and sharp and is used as an industrial abrasive. Powdered rock can cause a jet engine to shut down.
Shishaldin is a symmetrical cone with a base diameter of 10 miles (16 kilometers), the observatory said. The 660-foot (210-kilometer) funnel-shaped crater often spews steam and occasional amounts of ash.
There have been at least 26 confirmed eruptions at Shishaldin Volcano since 1824. Most were small, but the observatory said a 1999 eruption produced an ash cloud that reached 8.5 miles (14 kilometers).
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