After a lull observed since early January, inflation (swelling) and superficial volcanic-tectonic seismicity (0 to 2 km depth) have resumed significantly since 22 January at Piton de La Fournaise.
Thirty-five superficial volcanic tectonic earthquakes were recorded under the summit craters (0-2 km deep) between January 22 and January 26, and volcano inflation resumed at rates similar to those observed at the end December (elongation of 0.5-1 mm per day between stations in the summit zone).
Top: Balance of superficial volcano-tectonic seismicity at Piton de la Fournaise from 18 September 2016 (end of last eruption) to 26 January 2017. - below: deformation since last eruption (11-18 September 2016, yellow ). Here is shown a baseline (distance between two GPS receivers) crossing the Dolomieu crater from north to south (in black the raw data, in blue the smoothed data over a week). A rise is synonymous with elongation and therefore swelling of the volcano - doc. OVPF - IPGP
At the same time, soil CO2 concentrations at the Bourg Murat (observatory site) and volcano cottage began to fall, reflecting the arrival of magma to more superficial levels. It should be noted that the eruptions of 2015 and 2016 were preceded by a drop of CO2 on these distant stations.
The OVPF concludes that the signals recorded since January 22 show that the deep magma supplies have resumed and feed the surface reservoir about 1.5-2 km below the summit craters.
Source: OVPF - Activity Bulletin of 27 January 2017
After 18 years of calm, the Sabancaya, located 75 km from Arequipa, has entered a new eruptive phase since 6 November 2016.
It is characterized by explosions and regular gas and ash emissions, affecting populations and land Grown within a radius of 40 km. The volcano is under the supervision of the OVI, which distills its relations only sparingly.
Source: OVI webcams - Ingemmet
The Turrialba has spent a week without ash emissions since January 20th.
This situation did not last, since this 27 January towards 8:15, an emission of ashes was observed by the webcams. The plume is weak and does not exceed 300 meters above the crater, rapidly dispersed by the winds to the southeast. The activity is accompanied by a volcanic tremor amplitude a little greater than that recorded in recent days.
Sources: Ovsicori & RSN
The explosive activity is maintained at the Colima, magnified by the photos. The one of Sergio Tapiro is exceptional and deserves an observation in details.
Colima - 26.01.2017 / 22h04 - the magic of a beautiful explosion captured by Sergio Tapiro - click to enlarge.
A new explosive eruption began on the 27th at 8:24 AM AKST / 17:24 UTC at Bogoslof, accompanied by a cloud of ice and ashes that reached 7,500 meters, heading east. The seismicity associated with the ash emission remained high for 48 minutes, before decreasing towards 9:12 local.
This week, there are five significant explosive episodes: on 20, 22, 24, 26, & 27.01. The volcanic clouds remained detectable by the satellites for hours, transported by the prevailing winds towards Unalaska; They are rich in ice, which marks the influx of sea water into the eruptive column.
The morphology of the island and its coast line continue to change with the eruptions which succeed each other; The eruptive vent remains below the sea level in the northern part, marked by the presence of ascending volcanic gases. There are no signs of lava on the surface.