Volcanos

Roundup of Global Volcanic Activity

Stromboli (Eolian Islands, Italy): The eruptive activity has remains more or less unchanged: the lava flow is still active while sporadic explosive activity continues from the summit vents. As lava output rates from the 650 m vent fluctuate, the front of the lava flow, located in the central part of the Sciara del Fuoco since 6 Sep, advances and retreats in the lower part of the Sciara, sometimes almost reaching the sea. A short-lived overflow of lava to the northern part of the flat area at approx. 600 m occurred this morning.

Ontake-san (Honshu): The death toll from Saturday's powerful, and deadly explosion of the volcano has now climbed to 48, press reports. The eruption was a sudden, unexpected (and unpredictable) phreatic explosion, i.e. caused by sudden evaporation of overheated water in the hydrothermal system of the volcano. It took more than 250 climbers on the mountain, a popular hiking destination, and a sacred place for Japan's religious worshipers, by surprise. It is unclear whether this eruption is or not a precursor of a possible magmatic eruption in a near to medium future, i.e. caused by fresh magma coming to the surface. While search and rescue operations continue at high intensity, Japan's monitoring scientists are keeping an eye on possible changes that could indicate such a development. On the other hand, it is entirely possible, that the explosion remains a single event with no magmatic eruption following.

Sinabung (Sumatra, Indonesia): The volcano continues to slowly extrude viscous lava feeding the lava lobe on its southeastern flank. Occasional rockfalls, caused by instabilities on the steeper upper parts of the lava flows, continue to occur from time to time and represent a major hazard: Two larger ones occurred yesterday and produced pyroclastic flows that traveled 3.5 km distance to the southeast. Seismic activity has been generally low along with the persistent effusive activity which has been going on for more than 10 months now.

Dukono (Halmahera): Explosive activity continues at the volcano. An ash plume rising to 7,000 ft (2.1 km) was reported yesterday evening extending 40 km to the NE (Darwin VAAC).

Popocatépetl (Central Mexico): No significant changes have occurred during the past weeks. The volcano's activity has been characterized by constant degassing and occasional small explosions with ash plumes up to 1-2 km height. Crater glow is visible at night from the summit.

Santiaguito (Guatemala): Activity remains mainly effusive and the viscous lava flow on the SE side of the dome continues to advance slowly through the Nima 1 ravine. No explosions have been observed recently, but bad weather also prevents detailed observations much of the time.

Fuego (Guatemala): The volcano's activity has been fairly stable over the past weeks. Mild to moderate strombolian explosions eject abundant incandescent material to up to 150 m height and produce ash plumes rising up to approx. 800 m. Stronger explosions are accompanied by shock waves that can be felt in nearby villages. Light ashfall occurrs from time to time in areas up to 12 km downwind. No lava flow was active this morning.