Volcano Update from Archive

Saturday, May 29, 2010 1:29 PM ChST (Saturday, May 29, 2010 0329 UTC)

Sarigan Volcano
16°42'29" N 145°46'48" E, Summit Elevation 1765 ft (538 m)
Current Volcano Alert Level: UNASSIGNED
Current Aviation Color Code: UNASSIGNED

A submarine eruption is underway near Sarigan Island in the Northern Mariana Islands. Volcanic activity observed on Thursday, May 27, south of Sarigan Island has increased, and the Guam Weather Forecast Office reported that recent satellite images indicate that the affected area is about twice the size of Sarigan Island. An observer from the Commonwealth of the Northern Mariana Islands (CNMI) Emergency Management Office (EMO) overflew and photographed an elongate patch of discolored ocean water and possible light-colored floating debris about 6-7 miles south of Sarigan Island on Thursday. At that time, the area of discoloration and debris extended over about a mile. Successive satellite images indicate that this is a point-source that has dramatically expanded in breadth. The activity appears to be centered about 6-7 miles south of Sarigan, probably on the southern extension of the submarine ridge upon which Sarigan is constructed.

AVO is in contact with EMO and other government agencies in the area and we will attempt to gather more information to assess the nature of this activity. Submarine eruptions are not uncommon in the Marianas Islands; mariners in the area should remain alert for floating debris and avoid areas of strongly discolored or disturbed water. Near-sea level eruptions can be dangerous producing ash laden explosions, ash and ballistic fallout, and water waves. AVO maintains no monitoring equipment on these submarine volcanoes and therefore warning of eruptive activity is not possible.

USGS Northern Marianas Duty Scientist (808) 967-8815