Volcano Update from Archive

Saturday, May 29, 2010 9:53 AM ChST (Friday, May 28, 2010 2353 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

On Thursday, May 27, an observer from the Saipan Emergency Management Office (EMO)

overflew and photographed an elongate patch of discolored ocean water and

possible light-colored floating debris about 5 miles south of Sarigan

Island in the Northern Marianas. The area of discoloration and debris

extended over about (1) mile but scale is difficult to tell from the

photographs. We have no information on the direction of drift of this

debris. It is possible that this material reflects a recent or ongoing

submarine eruption or intense fumarolic emission from an underwater

volcano nearby.

Possible sources, if it is volcanic, include Zealandia Bank, a

fumarolically active sea-level volcano located about 13 miles

north-northeast of Sarigan; a seamount located about 8 miles northeast of Anatahan along the submarine ridge extending from that volcano; and the submarine southern extension of the 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

phenomenon. 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,

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