Sinabung, Pacaya, Sabancaya activity and seismic swarm in Reykjanes Peninsula.

In Sinabung, in the province of Karo on Sumatra, from 6:42 a.m. to 8:20 a.m. WIB on March 2, 2021, there were 13 pyroclastic avalanche flows, with a sliding distance of 2,000 to 5,000 meters to the southeast, and the height of the ash column is more than 5,000 meters, the wind is weak to the west - southwest. Warm clouds reach the Lauborus River in the east-southeast sector.

The aviation code is red, before being reduced to orange.

Ash falls are found in various villages, with a thickness of 3 cm.

The Himawari-8 satellite picked up an ash cloud drifting west.

The seismicity of March 2 between 00 and 6 a.m. is characterized by:

- 1 eruption earthquake, with an amplitude of 40 mm, and the duration of the earthquake was 191 seconds.
- 13 earthquakes linked to pyroclastic flows, with an amplitude of 120 mm and an earthquake duration of 143-485 seconds.
- 35 collapse / avalanche earthquakes, with an amplitude of 10 to 65 mm and a duration of 22 to 160 seconds of the earthquake.
- 23 low frequency earthquakes, with an amplitude of 5 to 25 mm and the duration of the earthquake was 10 to 40 seconds.
- 1 remote tectonic earthquake
- 1 episode of continuous tremor with an amplitude of 2-5 mm, dominating 3 mm.
 

The activity level remains at 3 / siaga with prohibitions of 3 to 5 km. depending on the flanks concerned
 

Sources: PVMBG, Magma Indonesia, Beidar Sinabung, Nachelle Homestay, and local news agencies

In the early hours of March 1, 2021, Insivumeh recorded a notable increase in the internal seismic activity of the Pacaya, corresponding to an increase in Strombolian activity.

According to observers of the observatory, explosions expel ballistic materials to a height of up to 500 meters above the crater; this activity is accompanied by a plume of ash and gas at 3,500 m. asl., moving west and southwest.

Ash falls are observed in El Patrocinio, with possibilities in Los Rios, Los Jazmines El Rodeo, San José, and the municipalities in the same direction.

To be continued

Source: Insivumeh

The eruptive activity of Sabancaya between February 22 and 28 remains at moderate levels, with an average of 91 daily explosions, and the observation of plumes of ash and gas up to 2,000 meters above the summit.

During this period, I.G. Peru recorded 1977 earthquakes of volcanic origin, associated with the circulation of internal fluids. VT earthquakes, of magnitude between 1.9 and 2.8, occur mainly north of the volcano.

The deformations do not present any significant anomalies, except for slight inflation in the north. The satellites did not identify any thermal anomaly.

The volcanic alert remains in Naranja, with an inaccessible area of ​​12 km. radius

Source: I.G.P.

New data provides reason to take a closer look at the magma intrusion scenario beneath the Fagradalsfjall area on the Reykjanes Peninsula.

Mount Fagradalsfjall, the westernmost part of the Reykjanes Peninsula's mountain ridge, is actually a small plateau. Some hyalocaslite ridges protrude, especially in the western part. Its highest altitude is 385 m. above sea level.

I reproduce the IMO update from 03/01/2020 at 6:15 p.m.:

“The Scientific Council for Civil Protection met in a teleconference today to discuss the earthquake on the Reykjanes Peninsula. The meeting was attended by representatives of the Icelandic Meteorological Office, University of Iceland, Environment Agency, Isavia-ANS, HS-Orka and ÍSOR.

It was stated at the meeting that the Meteorological Bureau's automatic seismic system has measured around 1,800 earthquakes since midnight and that they are mostly confined to the SW area of ​​Keilir and Trölladyngja. Of those 1,800, 23 earthquakes of magnitude 3 or greater and about 3 earthquakes are of magnitude 4 or greater. The largest of midnight was measured at 4:35 p.m., with a size of 5.1 and it came from about 1 km ASA through Keilir.

The Scientific Council also reviewed the satellite images (InSAR) received today. Excerpts from these images show more entries than has been previously seen in the region in recent days. The most likely explanation is that magma is forming under the area where the greatest seismic activity has taken place in recent days. These new data will be better processed, for example by means of a model, in order to better inform the course of events.

In light of this new data which was discussed at a Scientific Council meeting today and which has been reviewed by experts, it is important to take a closer look at the magma intrusion scenario beneath the area. by Fagradalsfjall.
 

The possible scenarios are:

1. Seismic activity will decrease in the coming days or weeks.
2. The eruption will increase with larger earthquakes, up to magnitude 6 near Fagradalsfjall
3.An earthquake with a magnitude of up to 6.5 will have its source in the Sulfur Mountains.
4. Magma intrusions continue near Fagradalsfjall with either:
- The magma intrusion activity decreases and the magma solidifies
- they lead to a lava flow which will probably not threaten the colonies.

Current activity on the Reykjanes Peninsula is divided into chapters and it is difficult to predict the exact development and whether one scenario is more likely than another. New data is expected later this week that could further shed light on the reasons for this crash. The Scientific Council will meet again tomorrow to make a new assessment of the available data as well as to assess new measures. "

Sources: IMO & mbls