Subject: Activity level of Nevado del Ruiz volcano.
Activity level Yellow 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, reports that:
During the last week, the volcanic system continued to show unstable behavior. The recorded seismic activity was mainly due to the fracturing of the rock in the volcanic structure. This type of seismicity was in the North, the North West, North East and South West areas of the Arenas crater and to a lesser extent in the South West. The depths were between 1.1 km and 8.8 km. The maximum magnitude recorded during the week was 2.3 ML (local magnitude), corresponding to an earthquake on October 21 at 9:53 (local time) at a depth of 3.4 kilometers. Two small increases in seismic activity occurred during the day on 22 and 23 October in different distal areas of the Arenas crater.
Seismic activity associated with fluid dynamics in volcanic conduits, was characterized by the recording of LP type earthquakes (long time) and episodes of volcanic tremor of short duration. Some of these events were associated with emissions of gases and ash in the atmosphere, which could be verified by web cameras installed in the volcano region, official reports Pnnn and technical staff working in a ground mission in the volcano area of ??influence. Seismicity related to fluid circulation is situated mainly in the Southeast sector of Arenas crater and near this one. The volcanic deformation measured from electronic inclinometers, GNSS stations and satellite images, which record changes in tilt, position and shape of the volcano during the last assessment period, showed no major changes.
The volcano continues to emit into the atmosphere of significant amounts of water vapor and gases, including sulfur dioxide. The column of gas, steam and ash reached a height of 2000 meters above the volcano’s summit on October 22. The direction of the dispersion of the column was in harmony with the wind regime, which during the week ranged from the Southwest and Northeast compared to the volcano but also the column was repeatedly observed during week with a vertical trend.
October 28, 2015. Nevado Del Ruiz, Colombia :
Source : SGC
Photos : SGC ( archives)