Story highlights Eruption on Alaskan island causes raising of aviation alert

Ash cloud reached at least 35,000 feet, observers say

(CNN) A volcanic eruption Sunday prompted the temporary raising of the highest aviation alert, the Alaska Volcano Observatory (AVO) said Sunday.

The event, which took place on Alaska's Bogoslof Island, part of the Aleutian island chain, caused the issuance of a code "red" aviation alert, which was subsequently downgraded to "orange."

The cloud from the eruption reached at least 35,000 feet, and possibly as high as 45,000 feet, the observatory said.

"We actually went to color code red this afternoon because of numerous lightning detections and increased seismic signals," Jeffrey Freymueller of the Geophysical Institute at the University of Alaska, Fairbanks tells CNN.

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"Lightning in the Aleutians is mostly due to volcanic plumes, as the meteorological conditions for lightning are not common," Freymueller said.

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