Weekly activity report of the Nevado del Ruiz volcano, from 8 to 14 March 2016.
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 the last week, the volcanic system continued to show unstable behavior. The recorded seismic activity was mainly associated with fluid dynamics in volcanic conduits, which was characterized by the occurrence of earthquakes long period (LP), short pulses of volcanic tremor and continuous tremor episodes with different energy levels.Some of these signs have been associated with the emission of ash process, sometimes confirmed by the images captured by the cameras installed in the Volcano area and reports of the Colombian Geological Service officials and the National Park Of Los Nevados (NNNP) . This seismic activity was localized mainly near the Arenas crater in the southern , southeast and northwest sectors of the volcano. Do not rule out new episodes of these signals with higher energy levels and ash emissions in the atmosphere as at other times during the past 15 months may arise. The ashes can be dispersed according to the wind conditions prevailing in the region. The above activity has been accompanied by thermal anomalies near the Arenas crater.
Seismic activity related to the fracturing of rocks in the volcanic structure was important, especially for 12 and 13 March, with an increase in seismic activity in the Northwest area of ??the volcanic structure. The occurrence of a seismic event of magnitude 3.0 ML (local) on March 12 at 2:33 (local time), located in the northwest sector compared to the Arenas crater at a depth of 5.6 km was recorded, reported as felt by staff of NNNP in Brisas area. In addition, two other earthquakes, reported as felt in the same area on March 12 at 5:08 (local time) with a magnitude of 2.3 ML (local scale) and March 13 at 20:31 (local time), to magnitude 2.8 ML (local scale), located in the northwest and northeast of the Arenas crater, at 5.6 and 3.6 km depth, respectively , were recorded. Other active seismic sources during the week were the South East , North, Northeast zones and the Arenas crater himself, at depths ranging between 0.67 and 7.72 kilometers.
The volcanic deformation measured from electronic inclinometers, global navigation satellite systems (GNSS) and satellite images, which record changes in the tilt, the position and shape of the volcano (respectively) during the last assessment period continues to show recorded changes.
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 1,800 meters above the volcano’s summit on March 8. 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 south – east over the volcano.
The Nevado del Ruiz shows clear evidence that the volcanic system is unstable and continues to evolve. New events that may indicate an acceleration of the process, involving greater instability of it and consequently changes in the level of activity is not excluded. While the instability of the volcano smoldering for more than five years, it is essential not to used to a seemingly monotonous behavior of the volcano and be attentive to official information to be published by the Colombian Geological Service.
March 17, 2016. Nevado Del Ruiz , Colombia :
Source : SGC
Photos : SGC ( archives)