On January 9, Sernageomin, with the collaboration of ONEMI BioBio, made an overflight of the Nevados de Chillan volcanic complex.
They were able to identify the establishment and growth of a lava dome inside the active crater, on the crack observed during the overflight preceding 21 December. The fissure of 30 to 40 meters long present emissions of water vapor and gas, and has a temperature up to 480 ° C.
The dome corresponds to the effusive exit start of a magmatic body, which could be prolonged in terms of weeks or months. The seismic signals and other parameters indicate a rise of a magmatic body likely small, without ruling out the possibility of a more energetic explosion. The Sernageomin recalls that 90% of the domes set up have destroyed explosively.
The alert level is Amarillo, with a prohibited area of 3 km radius around active craters.
Source: Sernageomin report of 09.01.2018 / 22.10 local.
In Copahue, VLP seismic activity suggests the action of a magma body at relatively low levels, and an interaction with the volcano's hydrothermal system, which results in emissions of water vapor and gas. With the system remaining in a state of equilibrium, the technical alert level remains green, with an access restriction of 1,000 meters radius around the crater.
Sources: Sernageomin & Twitter / Valecaviahue
In Sheveluch, an explosion produced an ash plume that reached 10 to 11,000 meters, before drifting to the northeast over 20 km on 9 December. KVERT has raised the aviation code to red, 09,01,2018 at 23:10Z.
At 01:15 on December 10, the ash cloud was reported extending 230 km to the ENE of the volcano.
The aviation code was then lowered to orange, with the ash cloud extending 400 km eastward at 2:54Z.