Weekly Bulletin activity of the volcano Nevado del Ruiz, from 22 to 29 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. This fluid activity was characterized by the appearance of long period earthquakes (LP) and short volcanic tremor pulses with significant levels of energy, which were recorded individually or simultaneously.
These episodes of tremor was were also continued with different energy levels. Some of these seismic signals were associated with ash emission 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 Los Nevados (NNNP ). These events have been located in the Arenas crater and in the Southeast sector of the volcano. New seismic signals of this type with high levels of energy and ash emissions in the atmosphere are not excluded, which can be dispersed according to the wind conditions prevailing in the region.
Seismic activity related to the fracturing of rocks in the volcanic structure continues to present significant energy levels and shows an increase compared to the number of earthquakes recorded the previous week. Earthquakes are located mainly in the west and southwest of the volcano, and to a lesser extent, in areas close to the Arenas crater and northern sectors, Southeast and Northwest of the volcanic structure. The depth of these events was between 1.1 and 8.1 km. A seismic increase on March 27, which took place in East and South-West and, to a lesser extent, in the North and the South distal areas was highlighted. The maximum amplitude of the week matches the recorded earthquake on March 27 at 11:11 (local time), with a magnitude of 2.7 ML (local scale), located in the southeast sector of the volcano to a depth of 3.5 km.
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 record changes .
The volcano continues to emit into the atmosphere large amounts of water vapor and gases, including sulfur dioxide (SO2), which is distinguished as it was estimated by the permanent stations SCANDOAS installed in the volcano area and satellite imagery.
The column of gas, steam and ash reached on 25 and 26 March to a maximum height of 1400 meters above the summit of the volcano. 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 over the volcano.
March 31 , 2016.Nevado Del Ruiz , Colombie :
Source : SGC
Photos : SGC ( Archives)