January 07, 2016. EN. Nevado Del Ruiz , Popocatepetl , Sinabung .
January 07, 2016.
Nevado Del Ruiz, Colombia :
Weekly activity bulletin of the volcano Nevado del Ruiz, from December 29, 2015 to January 4, 2016
Subject: internal activity level of the Nevado del Ruiz volcano.
The level of activity continues at:
level of activity Yellow or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the Nevado del Ruiz volcano, the Colombian Geological Service reports that:
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 type of seismicity was characterized by the appearance of continuous tremors and earthquakes long period (LP), located mainly in the vicinity of Arenas crater and in the Southeast region of the volcano. The continuous tremor signal has introduced low energy levels and has remained constant since January 1, 2016. Do not rule out new episodes with high levels of energy of this signal, which is associated with gas and ash emissions in the atmosphere.
These processes were accompanied by thermal anomalies that can be followed using satellite images provided by different organizations, such as the portal Mírová from Italian universities of Turin and Florence. A thermal anomaly was observed on December 31, the highest level since access to these images, these abnormalities have been identified in the vicinity of Arenas crater, confirming the instability of the Nevado del Ruiz confirming that the volcanic processes continues to evolve.
As for seismic activity related to the fracturing of the rock in the volcanic structure, this type of seismicity was located mainly in the distal areas in North, South and Southeast compared to the Arenas crater and, to a lesser extent in the Arenas crater. The depths of earthquakes vary between 0.67 and 8.0 kilometers. The maximum magnitude recorded during the week was 1.6 ML (local magnitude), corresponding to an earthquake on January 1st at 10:39 p.m. (local time) at a depth of 5.84 km.
The volcanic deformation measured from electronic inclinometers, global navigation satellite systems (GNSS) and satellite images, which record changes in tilt, position and shape of the volcano (respectively) in the last evaluated period, showed no significant changes.
The volcano continues to emit into the atmosphere large amounts of steam and water gas, including sulfur dioxide (SO2), as has been estimated by the SCAN DOAS permanent stations installed on the volcano zone and by satellite imagery.
The column of gas, steam and ash reached a height of 1700 meters above the summit of the volcano on December 28. The direction of the dispersion of the column is in line with the regime of prevailing winds in the region, who, during the week showed a predominant direction from the volcano toward the northwest.
It is considered that the volcanic system continues to evolve. No new event that may indicate an acceleration of the process, involving greater instability of it and consequently changes in the level of activity is recorded. It is essential to pay attention to official information to be published by the Colombian Geological Service.
Source : SGC.
Photos : SGC ( archives)
Popocatepetl, Mexico :
January 06 11:00 h (January 06 17:00 GMT)
In the last 24 hours the seismic records of the monitoring system at Popocatépetl volcano registered 16 low-intensity exhalations with slight amounts of ash. Also 6 explosions were recorded . The cloudy conditions allowed partial observation of a weak emission of steam and gas that winds carried easterly. Additionally an explosion train that started at 18:30 h yesterday and that continues to this time is being recorded .During the night slight incandescence was observed, increasing with the main exhalations with emission of incandescent material .
From dawn and up to the time of this report a continuous emission of steam, gas and ashes is being blown eastwards .
It is probabale that the following towns might receive some ashfall: In the state of Puebla, Huejotzingo, Domingo Arenas, San Andrés Calpan, San nicolas de los Ranchos, San Buenaventura Nealtican, Tlaxcalancingo, Santiago Momoxpan, Cuanalá, San Francisco Ocotlán, Puebla de los Ángeles and Sanctorum. In the state of Tlaxcala, Nativitas Zacatelco, Santana, Nopalucan, Tlaxcala de Xicoténcatl, Papalotla and Teolocholco.
CENAPRED emphasizes that people SHOULD NOT go near the volcano, especially near the crater, due to the hazard caused by ballistic fragments .
This type of activity is included within the scenarios Volcanic Traffic Light Yellow Phase 2.
Source : Cenapred
Photos : Fabian GR , Volcan Popocatepetl FB.
Sinabung, Indonésia :
Elevation 2460 m
PVMBG reported that during 21-28 December inclement weather sometimes prevented visual observations of Sinabung and the growing lava dome in the summit crater. As many as 21 hot avalanches and pyroclastic flows traveled 0.7-1.5 km ESE, producing ash plumes that rose 1 km. Ash plumes from explosions rose as high as 3 km and drifted E and SW.
Seismicity consisted of avalanche and pyroclastic-flow signals, low-frequency and hybrid events, tremor, tectonic events, and volcanic earthquakes. Seismicity fluctuated at high levels, although it had declined compared to the previous week, and indicated lava-dome growth. The Alert Level remained at 4 (on a scale of 1-4), indicating that people within 7 km of the volcano on the SSE sector, and within 6 km in the ESE sector, should evacuate.
Source: PVMBG, GVP.
Photo : ibtimes.co.uk ( 2014)