According to the Alaska Volcano Observatory, the Shishaldin volcano - the highest mountain of the Aleutian chain, located about 1095km (680mi) southwest of Anchorage - kicked out a plume of ash as high as 8535m (28,001ft) above sea level and stretching about 145km (90mi) over the Gulf of Alaska as of Sunday, January 19. The density and height of the plume led officials to trigger a ''code red'' warning for aviators to avoid the area.
Disruptions to transportation are possible in the vicinity of the volcano over the coming hours and days, particularly in the event of a hazardous eruption.
Shishaldin volcano, located in the most active region in Alsaska for volcanic activity, has been in an on-and-off eruptive phase since July; it is the second ''red alert'' warning issued since then.
Individuals present in affected areas are advised to keep abreast of the situation and to follow any instructions issued by the local authorities.