Subject: Activity Bulletin of the Nevado del Ruiz volcano.
The level of activity continues at:
Activity level Yellow or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the Nevado del Ruiz, the SERVICIO Geologico COLOMBIANO reports:
During last week, the seismic activity of the Nevado del Ruiz volcano was mostly associated with rock fracturing within the volcanic edifice, showing an increase both in number of events and energy released by now the trend reported the previous week. Earthquakes were mainly located in the North distal area, about 7.0 km from the Arenas crater at depths between 6.0 and 8.0 kilometers.
And in the Northern Zone, to 4.0 km on average of the Arénas crater, with depths between 4.0 and 6.0 km, and in an area 3.5 km away to the east of the crater, to depths between 4.0 and 6.0 km. The maximum amplitude of the week corresponds to the earthquake registered on April 13 at 22:48 (local time), with a magnitude of 3.0 ML (local magnitude), located in the North distal area at a depth of 7.4 km. Seismic activity related to fluid dynamics in volcanic conduits, was characterized by the occurrence of earthquakes long period (LP) and very long period (VLP). Continuous volcanic tremor episodes were also recorded,with low energy levels and pulse mode with different energy levels, some of them associated with process of emission of ash . These events have been located in the Arenas crater and in the Southeast sector of the volcano.
The volcanic deformation measured from electronic inclinometers, global navigation satellite systems (GNSS) and satellite images to track changes in the tilt, the position and shape of the volcano (respectively), continues to show changes that are recorded.
The volcano continues to emit into the atmosphere large amounts of steam and water gas, including sulfur dioxide (SO2), as it was felt by the permanent stations SCANDOAS installed in the Volcano area and satellite imagery.
In the monitoring of satellite images provided by the site Mirova, some thermal anomalies near the Arenas crater were identified during the week. The largest anomaly was reported on 16 April, with a value of 21 Mw. The persistence of these anomalies confirms the instability of the Nevado del Ruiz volcano and confirmed the volcanic process continues to evolve.
The column of gas, steam and ash reached a height of 1,500 meters above the summit of the volcano. This height corresponds to the vapor column of April 12. The direction of the dispersion of the column was in line with the prevailing wind in the area, which during the week showed a predominant direction towards the northwest and northeast of the volcano.
April 24 , 2016.Nevado Del Ruiz , Colombie :
Source : SGC
Photos : Telemundo , SGC.