Activity of Taal, Stromboli, Fagradalsfjall and Sabancaya.

In the last 24 hours, the Taal Volcano Monitoring Network recorded two hundred and eighty-eight (288) volcanic earthquakes, including thirty-nine (39) low frequency volcanic earthquakes and two hundred and forty. nine (249) volcanic tremor events lasting from one (1) to twenty (20) minutes, and one low-level background quake that has persisted since April 8, 2021.

Most of these earthquakes were very shallow and generated within five (5) kilometers below the island of Taal Volcano or TVI and northeast of Taal Lake.

Upwelling of hot volcanic fluids in the main crater lake and active degassing of the main crater fumaroles which produced steam-laden plumes 300 meters high have been observed since daybreak. Sulfur dioxide (SO₂) emissions were on average 2,214 tonnes / day on May 17, 2021.

Electronic tilt monitoring recorded a slight but very sharp inflation from Taal Volcano Island that started yesterday, while longer term ground deformation parameters from electronic tilt, continuous GPS and InSAR surveillance continues to record very slow and steady inflation and expansion of the Taal region that began after the eruption of January 2020.

These parameters indicate a persistent magmatic activity at shallow depths under the edifice.

Alert Level 2 (Increased Agitation) is currently maintained on Taal Volcano, but high unrest is recurring and volcano conditions remain unstable. DOST-PHIVOLCS reminds the public that at Alert Level 2, sudden steam or phreatic explosions, volcanic earthquakes, minor ash falls and fatal accumulations or expulsions of volcanic gas can occur and threaten areas in and around TVI.

Source: Phivolcs notice of elevated unrest at Taal Volcano. 18.05.2021

The INGV reports that the amplitude of the Stromboli volcanic tremor has reached medium-low values, confirming the fluctuating trend between the medium-low and medium-high values ​​observed in recent days.
At the same time, the amplitude of the VLP signals and the explosion earthquake are maintained at low values.
The projection / spattering activity remained practically unchanged. Starting at 13:00 UTC and for about an hour, there was a slight increase in the intensity and frequency of unique explosions in the north and central-south sectors.
There is no significant change in the time series of soil deformation monitoring networks.

Source: INGV OE - Communications 05.17.2021

In Fagradalsfjall, the activity seems to be maintained with pulsating lava fountains, and strong volcanic gas emissions.

It was decided yesterday to continue the construction of the fortifications which are to prevent lava from flowing from the "anonymous valley" to Nátthaga.

Fannar Jónasson, mayor of Grindavík, decided to raise them according to the planned standards: see the diagram, on the one hand up to a volume of 8,400 m³, on the other hand up to a volume of 12,400 m³ - sana other details for now.

Sources: mbls & Óróapúls

The Geophysical Institute of Peru (IGP) reports that the eruptive activity of the Sabancaya volcano remains at moderate levels, that is to say with the recording of an average of 37 daily explosions, with columns of ash and gas up to 3.5 km altitude above the summit of the volcano and their consequent dispersion.

The IGP recorded and analyzed the occurrence of 733 earthquakes of volcanic origin, associated with the circulation of magmatic fluids within the Sabancaya volcano. An average of 37 explosions was recorded daily. During this period, Volcano-Tectonic (VT) earthquakes associated with rock fracturing were located mainly in the West, East, and Northwest of Sabancaya and presented magnitudes between M1.0 and M3.8.

The monitoring of the deformation of the volcanic structure using GNSS techniques (processed with fast orbits) does not present any significant anomalies. However, in general, an inflation process was observed in the northern sector (around the Hualca Hualca volcano).

Satellite recordings have identified the presence of 8 thermal anomalies (maximum value of 14 MW) associated with the presence of a lava body on the surface of the volcano's crater. The civil defense of the province of Caylloma reports light ash falls in the district of Chivay and in Achacota.

The alert level remains orange, with a prohibited zone of 12 km radius.

Source: I.G. Peru