During the week of December 3 to 9, the Merapi presented 4 pyroclastic flows, observed in the Bebeng River with a maximum sliding distance of 2200 m.
Lava boulder falls have been observed 190 times to the southwest, dominating the Bebeng River with a maximum slide distance of 2,000 m.
The southwest lava dome and the central dome were still growing. The volume of the southwest lava dome is 1,629,000 m³ and the central dome is 3,007,000 m³.
The intensity of the earthquakes is still relatively high this week.
The deformation of Mount Merapi, which was monitored using EDM this week, showed a distance shortening rate of 0.5 cm / day.
The activity remains at 3 / Siaga.
The current potential danger consists of lava avalanches and hot clouds in the southeast-southwest sector for a maximum of 3 km to the Woro River and 5 km to the Gendol, Kuning, Boyong rivers, Bedog, Krasak, Bebeng and Putih. The ejection of volcanic material in the event of an explosive eruption can reach a radius of 3 km from the summit.
This December 12, 2021 at 10:18 am WIB, pyroclastic avalanche flows were recorded on a seismogram with an amplitude of 27 mm and a duration of 158 seconds. The glide distance is 2,000 m to the southwest.
Semeru - area affected by pyroclastic flows and lahars - doc.earthobservatory.nasa.gov-images-149198
BNPB Pusdatinkom teams are monitoring one of the areas affected by the eruption of Mount Semeru precisely in the village of Kamar Kajang Sumberwuluh, Candipuro district, Regency of Lumajang. Thanks to aerial surveillance, we can see the damage to the colonization area of citizens due to lahars.
The losses amount to a total of 45 dead as a result of the pyroclastic flows. The number of missing persons reported so far is 9, 19 seriously injured and 19 with minor injuries.
Observations made by a field team of officers from the Dominica Office of Disaster Management (ODM), the Forestry, Wildlife and Parks Division and the Fire Services Division during a visit to the Boiling lake on December 1, indicated that water levels have declined since the previous visit on November 22. On December 1, the lake was about 15 m below its normal water level.
Further sightings by a local guide on December 7 indicated that there had been a further drop in water levels.
These fluctuations occur when the vents below the lake are blocked. This limits the flow of gas and water into the lake; this phenomenon is reversible and not necessarily linked to the increase in volcanic activity in the region.
During these episodes, harmful gases such as carbon dioxide can be released and small steam explosions can also occur.
The UWI recommends strongly limiting the time spent visiting the site.
The volcanic eruption of Cumbre Vieja presented yesterday characteristics more Hawaiian than Strombolian, with zero explosiveness, emission of ash or incandescent pyroclasts, and the continuous emission of lava, which flows on the previous flows, in particular on the areas central and south, and for the time being, not affecting a new surface.
The affected area continues to be estimated at 1,184 hectares, with a maximum width of 3,350 meters and damage to infrastructure, according to information provided by the Copernicus satellite, amounts to approximately 3,046 buildings affected.
Seismicity at intermediate depths remains low, while the number of earthquakes at depths greater than 20 kilometers remains very low.
Sulfur dioxide emissions, associated with the volcanic plume, continue to reflect a downward trend since September 23. The weather forecast predicts a predominance of the northeast wind over the eastern component, which assumes a favorable scenario for aeronautical operations.
Sources: IGN, IGME, InVolcan, DSN