Volcanos

Roundup of Global Volcanic Activity

Cleveland (Aleutian Islands, Alaska): The Alaska Volcano Observatory detected that a new (so far minor) eruptive episode has started at the volcano recently: "Elevated surface temperatures have been detected in satellite images at the summit of Cleveland for the past week, and an image from June 14 shows very light ash cover on the volcano's upper flanks. Thus the volcano has entered a renewed period of unrest and we are raising the Color Code to Yellow and the Alert Level to Advisory. The increase in temperature at the summit is consistent with renewed growth of the small lava dome within the summit crater. The possibility of sudden explosions has increased." (AVO)

Kuchinoerabu-jima (Ryukyu Islands): Another eruption occurred from the Shindake crater shortly after noon on 18 June. It was not directly observed due to cloud cover and the island being evacuated, but sent out a clear explosion signal picked up on seismic stations. Japan maintains the highest alert level (5 out of 5) and the evacuated island inhabitants are currently not allowed to return to their homes.

Bulusan (Luzon Island, Philippines): Another eruption, moderately strong, occurred 14:55 last Friday, producing an ash column that rose 1.5 km. The eruption was not directly visible, only parts of the ash plume could be spotted, but could be heard as rumbing in Monbon village.

Manam (Papua New Guinea): An ash plume rising to estimated 10,000 ft and extending 35 km NW was reported yesterday by Darwin VAAC. Manam has been having intermittent periods with mostly minor eruptive activity for several years. A phase of increased explosive activity has been going on since late March this year.

Raung (East Java): A strong thermal signal visible on satellite data suggests that eruptive activity in the volcano's summit crater has again picked up during the past two days. During late 2014 and early 2015, the volcano had been in strombolian activity and effused a lava flow inside its vast summit caldera. This activity had gradually decreased during the past months, but might now have resumed.

Wolf (Galápagos Islands, Ecuador): The eruption that started 4 weeks ago continues strongly, but from the location of the origin of the thermal signal it seems that since around 13 June, the eruption has been occurring from vents inside the vast summit caldera rather than from the fissure vents that opened on the upper ESE flank on 25 May. This could be because the dike (the fissure inside the edifice serving as pathway for the magma) that fed the original eruption has simply propagated into the caldera floor, or because an entirely new dike, hence a simultaneous second eruption has occurred. As judging from the thermal signal, the eruption continues with increased strength since mid June.

Pacaya (Guatemala): Mild strombolian activity has resumed in the main (Mackenney) crater of the volcano. INSIVUMEH reported intense degassing, small ash emissions, incandescence at night and volcanic tremor. The seismic activity of the volcano has been increasing during the past days accompanying the onset of the new eruptive phase. There is a possibility that it further increases and produces a more violent eruptive phase with lava fountaining and/or lava flow activity.

Fuego (Guatemala): Activity has been relatively intense. Strombolian-type explosions with abundant incandescent bombs up to 200 m and ash plumes rising 1000 m have been frequent. A lava flow of 200 m length is active in the direction of the Santa Teresa drainage (WSW side). Explosions generated strong rumblings and weak shock waves. In addition, locomotive-like degassing sounds lasting several minutes can often be heard.

Ubinas (Peru): A new phase of intermittent explosions and associated ash emissions from the volcano started Saturday evening (20 June). The new surge of activity has been accompanied by a rise of seismic activity since early June, characterized by earthquakes related to rock fracturing under the volcano and signals caused by internal fluid movements, both results of increased internal pressure. A weak thermal anomaly had also become visible on satellite data since mid June, as more heat is being transferred to the crater of the volcano. This announced the rising of a new magma batch that is now causing the currently still small eruptions.