Satellite images recorded over the past several days indicate that similar clouds have been intermittently streaming from many of the higher mountain peaks in the Wrangell Mountains that aren't volcanoes, the observatory reported.
The most likely explanation for such clouds, the agency said, is "the rise and cooling of moist air as regional air masses pass over the mountains."
Located about 45 miles east of Glennallen and towering 16,237 feet above sea level, Mount Sanford is the tallest volcano in the Wrangells. The cliff on its south face has a vertical relief of 8,000 feet.
"This precipitous wall is the source of nearly constant rock, snow and ice-falls onto the Sanford Glacier, and on occasion these falls produce minor, local vapor plumes," the observatory reported.
There is no record of an eruption at Mount Sanford since Alaska's written records began in the 1700s.
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