Weekly activity report of the volcano Nevado del Ruiz, from 1 September to 7 September 2015.
Subject: internal activity level of the Nevado del Ruiz volcano.
Yellow activity level or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the Nevado del Ruiz volcano, the SERVICIO Geologico COLOMBIANO through the OBSERVATORIO VULCANOLÓGICO Y SISMOLÓGICO OF MANIZALES, informs that:
During the last week, the volcanic system continued to present instability in his behavior. The recorded seismic activity was mainly associated with fluid dynamics in volcanic conduits. This seismic activity is characterized by recording several earthquakes type LP (long time) and episodes of volcanic tremor of short duration. These have been primarily associated with gas emissions and ash into the atmosphere. A volcanic tremor episode was recorded on September 4 at 00:30 (local time) with large energy levels. At the beginning of this episode, it was revealed a glow that could be seen by one of the web cameras installed in the volcano area. This seismicity associated with fluid movement is primarily located in and near the Arenas crater.
In addition, has continued recording of seismic activity associated with the fracturing of the rock in the volcanic structure. Earthquakes are located in the vicinity of the volcano at depths between 0.4 and 6.4 kilometers. The maximum magnitude recorded during the week was 1.4 ML (local magnitude), corresponding to an earthquake located 1.5 km north from Arenas crater, which took place on September 2 at 00:17 (local time) at a depth of 3.8 kilometers. Continuous volcanic deformation show some changes.
The volcano continues to emit into the atmosphere of significant amounts of water vapor and gases, including sulfur dioxide (SO2). The gas and vapor column reaches a height of 1400 meters above the top of the volcano, and sometimes, a gray color was observed because of the volcanic ash. The direction of the dispersion of the column was in harmony with the wind regime, which remained mainly directed to the northwest sector of the volcanic edifice.
In recent weeks, the Servicio Colombiano Geológico through the Observatorio Vulcanológico and Sismológico of Manizales has continued important socialization process of technical information with stakeholders in risk management, including the participation of different mayors from the municipalities in the area of influence from Nevado del Ruiz volcano, to continue to contribute to the social appropriation of geoscientists and volcanological knowledge for the well-being of communities and save lives.
While the volcano Nevado del Ruiz remains to this day a yellow level of activity, it is possible that additional changes occur in the behavior of volcanic activity, indicating greater system instability and may involve changes in the level of activity. So we reiterate to the authorities in the departments of Caldas and Tolima extreme actions aimed at risk reduction and management processes of the activity from Nevado del Ruiz volcano.
September 10, 2015. Nevado Del Ruiz, Colombia :
Photo : Ingeominas , SGC ( 04/2012) .