November 07, 2015. EN. Nevado Del Ruiz, Lascar, Villarica.

Home / blog georges Vitton / November 07, 2015. EN. Nevado Del Ruiz, Lascar, Villarica.

November 07, 2015. EN. Nevado Del Ruiz, Lascar, Villarica.

November 07, 2015.


Nevado Del Ruiz, Colombie :


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:

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 located in the north, northwest, southwest and northeast of Arenas crater and to a lesser extent, in the southeast sector and near this one, at depths between 1 , 3 km to 8.2 km. The maximum magnitude recorded during the week was 1.3 ML (local magnitude), corresponding to an earthquake on October 31 at 2:09 p.m. (local time), 3.2 km to the southwest of Arenas crater at a depth of 2.6 kilometers.


Seismic activity associated with fluid dynamics in volcanic conduits, was characterized by the recording of LP type earthquakes (long period) and episodes of volcanic tremor of short duration. Some of these events were associated with emissions of gases and ash in the atmosphere, verified by web cameras installed in the volcano area, official reports Pnnn and technical staff in field mission in the region of influence the volcano. Seismicity related to fluid circulation is mainly located in the southern sector of Arenas crater and near this one. The volcanic deformation measured from electronic inclinometers, GNSS stations and satellite images, which record changes in position and shape of the volcano during the last assessment period showed no major change .




The volcano continues to emit into the atmosphere of significant amounts of water vapor and gases, including sulfur dioxide (SO2). The column of gas, steam and ash reached a height of 1700 meters above the volcano’s summit on October 30. The dispersion direction of the column was in harmony with the wind regime, which during the week showed a variable direction between southwest and northwest over the volcano.

The Colombian Geological Service through the Volcanological and Seismological Observatory of Manizales is preparing to mark the 30th anniversary of the eruption of the Nevado del Ruiz volcano in 1985, which resulted in the loss of about 25,000 people in the departments of Caldas and Tolima . « Lessons of a disaster for Colombia and the world. The story should be the basis to build a better future.  »
The Colombian Geological Service through the Volcanological and Seismological Observatory of Manizales closely follows the evolution of the volcanic phenomenon and will continue to report timely to the changes that may occur.


Source : SGC


Lascar, Chili :

Continued yellow alert on the Lascar volcano.

On October 30, the Onemi decreed the alarm after detecting an emission of ash more than 2,500 meters high. The « Fach«  make an overflight on Sunday on the volcanic massif.
For the fifth consecutive day the yellow alert for the massif of Lascar volcano located in the Antofagasta region continue.

According to the report, after the volcanic activity the alert was extended for San Pedro de Atacama. Therefore, on Sunday, November 1, the Air Force of Chile made a reconnaissance flight over the area with a plane belonging to Aerofotogramético Lear Jet Service.
With this analysis, the Onemi and the SERNAGEOMIN continue to monitor the online behavior of the volcanic massif.



Based on the analysis of information collected by surveillance equipment and monitoring of volcanoes, the National Geology and Mining Service ( SERNAGEOMIN) through the Volcano Observatory of the southern Andes (OVDAS), communicate: –
During this month, a total of sixty-two (62) seismic events, including eight (8) who were classified as volcano-tectonic (VT), were recorded. These events linked to the fracturing process of a rigid material, provided a maximum power of local magnitude (ML) equal to M 0.5. Similarly, it was recorded fifty-four (54) events associated with the fluid dynamics inside the volcano, classified long period (LP) of local quantities (ML) equal to M 1.2 and lower and value of reduced displacement (DRC) of 0,7cm2.


On October 30 at 9:32 HL (12:32 GMT) through the webcam, ash emissions from the Lascar volcano was observed with a height of over 2,500 m, and heading north-east (NE) of the volcano, seismic signal that accompanied this process introduced a small displacement of 1 cm2, value considered as low to moderate.

Observations of glow, at night with IP cameras, were recorded, the latter being correlated with the thermal radiation released by Mirova (Medium Infrared Observation of volcanic activity).
From the data provided by the three GNSS stations, which measure the deformation of the surface of the volcano, it was observed during the last period, by the station located south of the active crater, a moderate scale movement, constant in time, showing a shortening of 1.8 cm of the length of the line crossing the active crater of the volcano

Sulfur dioxide emissions (SO2) of the Lascar volcano, recorded by the team DOAS (optical absorption spectrometry differential) of the Lascar station, located 6 km northnorthwest (NW) of the active crater presented a monthly average of 491 ± 47 t / day and a maximum value of 1171 t / day, registered on 30 October.
This increase in flow observed on 30, is associated with the increase in the internal activity of the volcanic system.

Source : Sernageomin,


Villarica , Chili :

A group of mountain guide CONAF and a professor at the University of Frontera (Temuco) is mounted on top of Villarrica volcano for about 11 hours to check the status of the path to the volcano.
The ascent was led by the Director of CONAF Araucania, David Joaunnet, as part of an agreement with the Onemi to assess the possibility of opening the way for the development of tourist activities.

According Jouannet, « it was observed that 90% of the road is in good condition. However, got to the top, we saw that the crater has changed shape in some areas. The platform that hikers could reach, was reduced in size , gas emissions are more frequent. « 



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The morphology of the volcano has changed, exceptionally this year, due to the large amount of snow that remained, compared to other massifs in the region.
« There is now a situation of insecurity for people who want access, but this can be controlled by small groups of hikers. It becomes dangerous if you want to go around the crater, where there are some differences of topographical conditions and danger, « said the leader of the expedition.


Source :

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