Weekly Bulletin activity of the volcano Nevado del Ruiz, from 05 April to 11 April 2016
The level of activity continues at: Yellow activity level or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the Nevado del Ruiz, the Colombian Geological Service reports that:
During the last week the seismic activity of the Nevado del Ruiz volcano presented mainly a seismic activity associated with the fracturing of rock in the volcanic edifice. This activity showed energy levels that significantly increase in numbers and showing a power similar to those reported in the week prior. Earthquakes are located mainly in the North West (North distal, about 6 km from the crater) and southwest of Arenas crater and to a lesser extent, to the north and west of it, at depths varying between 0.83 and 9.60 kilometers.
Seismicity located about 6 km northwest of Arenas crater at depths of between 5 and 8 km, corresponding to an increase in activity during the 4 and 5 April and which continues until issuance of this declaration. The maximum amplitude of the week is for the earthquake registered on April 8 at 5:33 (local time), with a magnitude of 3.0 ML (local magnitude), located in the distal northern sector of the volcanic edifice, at a depth of 7.20 km. Many of the events of that increase were reported as felt by officials of the National Natural Park of Los Nevados (NNNP) and the Brisas sector. Similarly, seismic activity related to fluid dynamics inside the volcanic conduits, as well as gas emission processes and ashes were recorded. This fluid activity was characterized by the appearance of long period earthquakes (LP) and short pulses of volcanic tremor with different energy levels. Tremor episodes also continued with different energy levels. 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.
The column of gas, steam and ash reached a height of 1800 meters above the summit of the volcano. This height corresponds to the emission of ash that was held April 5 at 6:50 (local time) observed from several municipalities in the departments of Caldas and Tolima. 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 of the volcano.
From the technical-scientific and instrumental analysis, it is considered that the volcano Nevado del Ruiz continues to evolve and it is possible that future events may indicate an acceleration of the process, involving greater instability thereof requires changes in it’s activity level. While the instability of the volcano covers more than five years, it is essential not to get used to his behavior and pay attention to official information to be published by the Colombian Geological Service.
The Colombian Geological Commission follows closely the evolution of the volcanic phenomenon and will continue to report timely to the changes that may occur.
April 15, 2016. Nevado Del Ruiz , Colombia :
Source : SGC
Photos : SGC ( archives)