In Sinabung, on Sumatra, a thick white plume is observed from 100 to 300 m above the top of the crater. Collapsing pyroclastic flows are noted, with a sliding distance of 1,500 m and avalanches with a sliding distance of 500 to 700 m to the east and south-east.
The seismicity of October 28 is characterized by :
- 1 earthquake linked to a pyroclastic flow of collapse
- 56 earthquakes of collapses
- 8 blast earthquakes
- 12 low frequency earthquakes
- 16 hybrid / multiphase earthquakes
- 2 local tectonic earthquakes
- 2 distant tectonic earthquakes
Communities and visitors / tourists not to carry out activities in the villages that have been relocated, as well as the location within a radial radius of 3 km from the summit of G. Sinabung, and a sector radius of 5 km for the south-eastern sector and 4 km for the east-north sector.
Sources: PVMBG, Magma Indonesia and Beidar Sinabung
In the western Aleutians, based on recent satellite detections of significant sulfur dioxide emissions and an increase in seismicity above the background level, the AVO has increased the color code of the aviation in Yellow and the alert level at the Korovin volcano in Advisory on October 28 at 5:51 p.m. Z.
Quiet earthquakes have been detected over the past two weeks, and sulfur dioxide outgassing has been detected four times in satellite data on Oct. 20 and 26.
Clear satellite views show no other signs of activity at this time. AVO will continue to monitor the volcano for signs of volcanic activity.
The Korovin is controlled by local seismic and infrasound sensors, satellite data and regional lightning detection instruments.
Korovin volcano is a stratovolcano 1533 m high and nearly 7 km in basal diameter, with two summit vents 0.6 km apart.
The northwest summit vent is a symmetrical cone with a small crater. The southeast summit vent is on the remnant of a cone with a steep-sided crater, about 1 km wide at the rim and at least several hundred meters deep. Intercalated lava flows and pyroclastic rocks make up the upper part of the crater wall, but the bottom of a hundred meters is almost vertical and apparently consists entirely of lava flows. A turquoise green lake fills the lower part of the crater; the color suggests the appearance of solfataric activity (Miller et al. -1998)
The thermal springs and fumaroles located on and near the volcano indicate an active hydrothermal system. The Korovin has erupted several times over the past 200 years, including 1973, 1987 and 1998, and it probably had small ash emissions as recently as 2005. Typical recent Korovin eruptions produce small amounts of ash and flow. occasional but small lava.
Normal explosive Strombolian volcanic activity is noted on Stromboli between October 19 and 25, 2020, at medium-low levels (6-10 events / h) and with medium-low intensity in the North and medium-high crater area. south-central.
In the area of the North crater, the N1 crater, with two emission points, produced explosions of low intensity (less than 80 m high) to medium (less than 150 m high) of coarse material (lapilli and bombs ) sometimes mixed at the end (ash).
The N2 crater, with two emission points, showed mainly low and medium intensity explosive activity of coarse materials mixed with fine. The average frequency of the explosions was between 5 and 10 events / h.
In the Center-South zone, the explosions were mainly of fine materials sometimes mixed with coarser, medium-high intensity (the products emitted often exceeded 250 m in height). The explosive activity showed frequency values varying between less than 1 and 3 events / h.
The seismological parameters do not show significant variations. The island soil deformation monitoring network showed no significant changes to report for the period. The SO2 flux remains medium-low.
Source: INGV OE