Weekly bulletin of activity of the volcano Nevado del Ruiz, from March 29 to April 4, 2016
The level of activity continues at:
Activity Levels 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 is associated with fluid dynamics inside volcanic conduits. This fluid activity was characterized by the appearance of long period earthquakes (LP) and short volcanic tremor pulses with important energy levels. Tremor episodes also continued with different energy levels.
Some of these seismic signals were associated with ash emission process, sometimes confirmed by images captured by the cameras installed in the volcano area, by visual assessment of the municipalities of Caldas and Tolima, and officials reports both the Colombian Geological Survey Service (CGT) and the National Natural Park of Nevado (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 emissions of ash in the atmosphere are not excluded, which can be dispersed according existing wind conditions in the region.
Seismic activity related to the fracturing of rocks in the volcanic structure continues to present considerable energy levels and showed an increase both in number and in power, regarding the events of the previous week. Earthquakes are located mainly in the northern volcanic areas, South and South-West of the crater of the volcano Olleta, and to a lesser extent in South and North of Arenas crater. Events depths were between 1.01 and 7.77 kilometers. An increase of seismicity recorded since April 4 and continues at the time of publication of this bulletin, which took place in the southern sector, and to a lesser extent in North distal and southwest sectors been demonstrated. The maximum amplitude of the week matches the recorded earthquake on March 29 at 20:01 (local time), with a magnitude of 3.4 ML (local magnitude), located in the northern sector of the volcano at a depth 3 , 0 km; and which was reported by the NNNP staff.
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 registered 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 a height of 3500 meters above the summit of the volcano. This height corresponds to the emission of ash that was held on March 31 at 8:04 (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 variable direction between the Northwest and the Southwest over 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 and amend consequently the level of activity.
April 07 , 2016. Nevado Del Ruiz , Colombia :
Source : SGC.
Photos : LUNWERG EDITORES