Volcanos

Roundup of Global Volcanic Activity

Etna (Sicily, Italy): Etna has remained calm at the surface since the most recent eruptive phase (violent strombolian activity from the NE and Voragine summit craters) ended on 26 May. The attached picture, taken on 3 June by volcanologist Boris Behncke (INGV Catania), shows significant changes of the summit region in the past weeks, in particular the near-complete filling of the Bocca Nuova and Voragine craters with lava and the partial collapses on the older NE crater.

Bromo (East Java, Indonesia): Intermittent mild to moderate emissions continue to occur at the volcano.

Kilauea (Hawai'i): The two new lava flows from Puʻu ʻŌʻō crater which emerged as surface breakouts from the partially blocked old lava tube on 24 May continue to be active, but have only advanced a bit during the past days. The old lava tube is still "working" as well (however, at presumably much reduced rate of lava throughput) and has been feeding scattered breakouts on the older June 27th lava flow field further to the northeast. At the moment, all active lava is within 5.4 km from the vent, far from inhabited areas to which it poses no threat. The summit lava lake remains active in Halema'uma'u crater. Its level varied slightly and is currently 31 m (102 ft) below the Overlook crater rim. According to HVO, "rates of seismicity are at background levels, with episodes of tremor associated with changes in the vigor of spattering within the Overlook vent. Sulfur dioxide emissions from the summit vent ranged from 4,100 to 8,000 metric tons/day over the past two weeks when measurements were possible during good trade wind conditions.

Masaya (Nicaragua): The lava lake remains active with little changes overall during the past weeks. Authorities have again closed public access to the crater rim.

Poas (Costa Rica): A small phreatic explosion occurred at the crater lake yesterday morning at 09:20 local time showing that the hydrothermal system of the volcano remains at elevated unrest.

Nevado del Ruiz (Colombia): Sporadic mild explosions continue to occur from time to time, generating small ash plumes. Overall, the volcano's activity has decreased during the past weeks, but it remains in an unstable state. It is impossible to predict how the activity will evolve (could calm down further or increase) in the near to medium future. SGC maintains alert level III (yellow) on its scale from IV (green) to I (red).

Santa Isabel (Colombia): During May 2015, GGC recorded an increase in small seismic activity associated with fracturing of rock inside the volcano, compared to April. The quakes (all below magnitude 2) were concentrated in the northern and eastern sectors of the volcanic edifice at depths ranging between 3.4 and 6.6 km. No other significant changes were detected at the volcano and its alert status remains at "green". A slight increase in rock-fracturing earthquakes has also been detected in the area south of Nevado de Santa Isabel volcano, in the area known as Cerro Spain.

Bristol Island (United Kingdom, South Sandwich Is): The eruption continues - Buenos Aires VAAC reports detecting ongoing ash emissions from satellite data. A moderately sized plume can be seen drifting east from the volcano.