Activity of Nevado del Ruiz, Popocatépetl, Santiaguito, and Piton de la Fournaise.

After the announcements of 17 September, and according to the multiparametric monitoring carried out by the Colombian Geological Service at the Nevado del Ruiz volcano, the seismic signal associated with the continuous tremor (linked to the exit of gases and ash in the atmosphere) has slightly increased in the last hours.

Due to the prevailing weather conditions in the area, mainly with the wind direction, it is possible that ash falls are recorded to the western and northwestern sections of the volcano, near the towns of Manizales, Villamaría and Chinchíná, Santa Rosa and Pereira. .

The level of activity continues in yellow or (III): changes in the behavior of volcanic activity. The Colombian Geological Survey continues to be attentive to any changes in the activity and will report it within the deadlines set by the official media.

Source: SGC Manizales 20.09.2018 / 09:46 local

In the last 24 hours, thanks to the monitoring systems of the Popocatepetl volcano, 76 exhalations have been identified, accompanied by water vapor, gas and light ash.

Also eleven explosions were recorded yesterday at 13:42, 13:49, 15:17, 17:18, 18:37, 19:08, 21:21, 21:28 and 23:35 and this morning at 01:48 and 03:17 h.

In addition, 542 minutes of low amplitude harmonic tremor were recorded.

This activity is part of the Amarillo Fase 2 alert; it is recommended not to access the volcano because of the dangers involved in the possible fall of ballistic fragments, and in case of rain, landslides and mudslides in the barrancas.

Source: Cenapred

In Guatemala, weak to moderate explosions at Santiaguito, are accompanied by an ash plume at 3,300 meters asl. dispersing to the southwest. In addition, small avalanches mark the sides SE and NE, and a white degassing is reported up to 2,900 meters asl.

Heavy rains on the Santa Maria-Santiaguito complex caused hot, sulfur-smelling lahars on the San Isidro-Tambor River, a tributary of Samala River, 25 meters wide and 2 meters high; it carries blocks of 1 to 2 meters in diameter, trunks and branches and fine materials

Sources: Insivumeh & Conred

At the Piton de La Fournaise, the eruption that began September 15 at 4:25 local time continues. The volcanic tremor (indicator of the surface eruptive intensity), has largely decreased compared to the previous days.
 

The SO₂ emissions recorded by the OVPF's permanent sensors are much higher than the atmospheric background (related to the volcanic gas plume), but have largely decreased, also reflecting a decrease in the flow of lava produced at the level of the eruptive mouth.
No significant deformities are noticeable since the onset of the eruption.
Surface flows were estimated from HOTVOLC satellite data (OPGC - Clermont Auvergne University), and ranged from 1 to 5 m³ / s during the day of 19 September.
An outline of the flow could be determined by the OI2 platform (OPGC - University Clermont Auvergne) from the Sentinel satellite data acquired on the 19th at the beginning of the day. This new contour does not show (or very little) evolution of the different casting fronts. The main evolution is an enlargement of the casting in its most upstream part.

Source: OVPF