At Ili Lewotolok, the PVMBG reports the sighting on December 5 of a white and gray plume with a height varying between 200 and 1,000 meters above the summit.
At the level of seismicity, it was recorded:
- 53 eruption earthquakes, with an amplitude of 10-31 mm lasting 14-45 sec.
- 88 blast / emission earthquakes
- 30 harmonic tremornon episodes
- 1 deep volcanic earthquake
- 1 distant tectonic earthquake.
The activity level remains at 3 / siaga and it is recommended that people around Mount Ili Lewotolok and visitors / climbers / tourists do not perform activities within a 4 km radius of the summit crater.
The Lumajang District BPBD Operations Control Center reported that Semeru volcanic activity continued this Sunday, December 6.
At 06:00 a.m., a pyroclastic avalanche flow was observed, with a sliding distance of 1500 meters.
In addition, an eruption was first observed with a height of smoke 400 meters from the summit. The plume was observed to be thick white and tilted to the north. Subsequent eruptions with columns up to 500 meters above the summit followed.
During this time, avalanches accompanied by pyroclastic flows occurred four times with a sliding distance of up to 500 meters from the tip of the lava tongue towards Besuk Kobokan.
The activity level remains at 2 / waspada, and it is recommended not to practice activities within a radius of 1 km from the crater / summit of Mount Semeru and at a distance of 4 km from the direction of the opening of the crater in the south-south-east sector, and be aware of the possibilities of pyroclastic avalanche and lahar flows along the volcano's drainages.
The Sernageomin recorded an LP earthquake, associated with a moderate explosion at the level of the crater of Villarica on December 5, 202 at 6:44 p.m. local time, accompanied by a plume of ash 160 meters high, drifting towards the SSE. Ash deposits are reported near the crater and in the direction of dispersion.
The volcanic technical alert is maintained in Amarilla.
Sources: Sernageomin and POVI
The Martinique volcanological and seismological observatory of the IPGP (Institut de physique du globe de Paris, CNRS) sent, Thursday, December 3, an explanatory note to the Prefect of Martinique to recommend a change to the yellow volcanic alert level ( 2nd level of alert on a scale which has 4) from Mount Pelée. The Martinique prefecture has followed this recommendation and the Montagne Pelée area goes to the yellow volcanic alert level as of December 4, 2020.
To answer the questions of the population on the new figures of the activity of Mount Pelée, public meetings will be organized. The first will take place this Saturday, December 5 at 2:30 p.m. at the market in the city of Saint-Pierre. Among the measures announced: the installation of sensors to monitor the chemical composition of water and gases and the installation of aerial reconnaissance by drones in the area where fumaroles were observed in the past.
- The increase in seismicity of superficial volcanic origin (up to 4-5 km below the summit) observed since April 2019, is therefore clearly above the base level characteristic for Mount Pelée.
- In April 2019, volcanic seismicity appeared at depth around and under Mount Pelée (more than 10 km below sea level). It could correspond to the arrival at depth of magmatic fluids.
- Finally, new recorded tremor-type signals were observed on November 8 and 9, 2020: they could correspond to a reactivation of the hydrothermal system.
Even if, in the current state of measurements, there is no deformation of the volcano on the scale of the observation network, the appearance, in a few months, of these three different types of seismic signals of volcanic origin shows a clear change in the behavior of the volcanic system, the activity of which is increasing from the base level observed over several decades.
Source: OVSM / IPGP