Activity of Kuchinoerabujima, Stromboli, Saunders island and Nevado del Ruiz.

A pyroclastic flow extending for about 900 meters was observed on the southwest side of Mount Shindake, accompanied by a co-pyroclastic plume 626 meters high, on Kuchinoerabu Island, in the Kagoshima prefecture. However, it did not reach the residential areas and no injuries or damage to the residences were confirmed, according to the local government.

The height of the ash plume could not be assessed by the VAAC due to the cloud cover.

According to JMA, the eruption occurred around 5.30 a.m. on February 3, 2020. Large deposits of ash were found scattered in areas about 600 meters from the crater.

Sources: JMA & VAAC Tokyo

From around 08:20 h UTC, the INGV was able to observe, via surveillance cameras, a modest overflow from the northern area of ​​the Stromboli crater terrace, which is currently confined to the summit area.

The flow front disintegrates on steep slopes and causes the rolling of material along the Sciara del Fuoco.
The magnitude of the volcanic tremor does not show significant associated variations.

The daily number of VLP earthquakes is high (18 episodes / hour). The thermal activity recovered from the cameras is average. The flow of SO₂ results in low values ​​(59 t / d), like the flow of CO₂ (121 t / d).

The explosive activity is centered on the NE crater sector, with the emission of gas, ash and slag. The Central and SW crater sectors are characterized by continuous degassing

Source: INGVvulcani & LGS daily report

Activity remains significant on Saunders Island, in the southern sandwich islands, as evidenced by satellite images of February 2, 2020 showing a significant white plume of gas and vapor.

Source: Sentinel Hub

The current morphology of the summit of Nevado del Ruiz (5321 m. asl.) and its main crater is the consequence of the complex interaction between volcanic, effusive and explosive processes (activity after the eruptions of 1845, 1985, 1989 and 2012 , the instability of the volcanic system produced by the current activity cycle (2010-2020)), the distribution of volcanic deposits, the erosion caused by global warming and the dynamics of ice cover

Currently, the Arenas crater has an irregular and elongated morphology, a diameter greater than 980 m in the SW-NE direction, a diameter less than 900 m in the SE-NW direction and an approximate depth of 300 m. The Arenas crater has large depressions contained in cornices or smaller terraces, internal walls, a bottom and several fields of fumaroles with emission of gas and ash. These fumarole fields remained with intermittent activity after the eruptions of 1985 and 1989 and with great intensity during the current activity cycle (2010-2020).

The upper part (the most superficial area) of the volcanic duct is located just at the bottom of the Arenas crater. This area of ​​the volcano is considered the most unstable and until August 2015, it was characterized by the presence of multiple active sources of emission of water vapor, sulfur dioxide (SO₂) and other volcanic gases, accompanied by ash emissions.

After the eruptions of 2012, the Nevado del Ruiz maintained an unstable behavior with the occurrence of earthquakes associated with the fracturing of rocks and the dynamics of fluids inside the volcanic system, permanent emissions (mainly vapor of water, SO₂ and ash) and the recording of a continuous high inflation. In August 2015, a new magma was set up and a lava dome began to build at the bottom of the Arenas crater. It continued to grow for several months, reaching in January 2020 a larger diameter estimated at 173 m, an estimated maximum height 60 m and an approximate volume of 1,500,000 m3.

Source: El Nuevo Domo de Lava del Volcán Nevado del Ruiz y la Geomorfología Actual del Cráter Arenas 2020 - Servicio Geologico Colombiano