May 20 , 2016. EN . Etna , Nevado Del Ruiz , Turrialba , Reventador .

Home / blog georges Vitton / May 20 , 2016. EN . Etna , Nevado Del Ruiz , Turrialba , Reventador .

May 20 , 2016. EN . Etna , Nevado Del Ruiz , Turrialba , Reventador .

May 20 , 2016.



Etna, Sicily :

ETNA UPDATE, 19 MAY 2016, 11:00 UTC

During the afternoon of 18 May 2016, the lava fountaining activity from Etna’s Voragine crater passed into a modest Strombolian activity, which continued to feed the lava overflow toward west until the late evening (see first image at left, recorded by the thermal camera at Bronte, EBT). A second lava flow, which was emitted from an effusive vent located near the lower of the two conelets formed during the subterminal activity of July-August 2014, at the eastern base of the Northeast Crater (NEC), expanded into the northern portion of the Valle del Bove in the direction of Monte Simone. This lava flow remained active until the early morning hours of today, 19 May 2016 (see second image at left, recorded by the high-definition camera at Monte Cagliato, EMCH), though its most advanced front seemed to be stagnating after midnight. Shortly before midnight, there was a new increase in the volcanic tremor amplitude, and the clinometer installed at Punta Lucia, about 1 km northwest of the NEC, recorded renewed inflation of the summit area of the volcano.



In the morning, the volcanic tremor amplitude showed a sharp increase, and contemporaneously loud and virtually continuous bangs were heard in populated areas to the east and south of the volcano. A dense eruption cloud was blown by the strong wind toward east at an altitude of little more than 1 km above the summit of Etna (see the third image at left, photographed from the village of Tremesteri Etneo, on Etna’s south flank). Ash and lapilli fell onto the east flank of the volcano, in an narrow sector immediately adjacent to the north to area affected by the tephra fall on the previous day. Observation of the activity was difficult due to rather poor weather conditions; Instrumental data – mainly the location of the volcanic tremor source and the origin of the infrasonic signals – indicate that a new paroxysmal episode was underway at the VOR. This was confirmed a few hours later when the images transmitted by the termal monitoring camera EBT (Bronte) revealed a new lava overflow toward west, feeding a lava flow that descended on top of the lava of the previous evening.


Eruptive activity was continuing at 09:00 local time, though the volcanic tremor amplitude was diminishing. At the time this update goes online, the inclement weather conditions are preventing observation of the activity going on at Etna’s summit.

The eruptive activity is monitored continuously by the systems of video and thermal cameras, seismic stations and ground deformation.

That night, Etna gave us a break and remained silent, the tremor has fallen back somewhat and the visibility seems to have improved compared to yesterday. To be continued.

Source : INGV, Boris Behncke.

Photos : Turi Caggegi , Francesco Tomarchio.



Nevado Del Ruiz , Colombia :

Weekly activity report of the volcano Nevado del Ruiz, from May 10 to 16 May 2016

The level of activity continues at:
Activity level 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 seismic activity of the Nevado del Ruiz volcano was mostly associated with rock fracturing within the volcanic edifice, showing a slight decrease in the number and energy released from the previous week. Earthquakes are located mainly in North proximal seismogenic zones , distal North and Northeast compared to the Arenas crater , in its neighborhood and in the crater itself. To a lesser extent, it was recorded activity in the southern areas of South-East and West of the volcanic structure.


The maximum magnitude recorded during the week corresponded to the earthquake registered on May 13 at 16:21 (local time) with a magnitude of 1.0 ML (local magnitude) at a depth of 4.14 km. It was located 2.1 km northeast of the Arenas crater. During the week, a seismicity episode type « Drumbeat«  low energy and short durationon May 13, from 11:47 to 11:54 (local time) was recorded. Seismic activity related to fluid dynamics in volcanic conduits characterized by the appearance of long period earthquakes (LP) and very long period (VLP), as well as episodes of continuous volcanic tremor of low level energy, were also recorded. Tremor pulses with different energy levels were noted, some of these signs were associated with the gas and ash emissions. These events were mainly located in Southeast sector of the volcano and near the Arenas crater. The registration of new seismic signals of this type with high levels of energy and ash emissions in the atmosphere are not excluded.


The volcanic deformation measured from electronic inclinometers, satellite global navigation systems (GNSS) and satellite images to track changes in the tilt, the position and shape of the volcano (respectively), continues to record changes.
The volcano continues to emit into the atmosphere large amounts of water vapor and gases, including sulfur dioxide (SO2), as has been estimated by the permanent stations SCANDOAS installed in the Volcano area and by satellite imagery.

On monitoring satellite images supplied by the site Mirova, thermal anomalies were identified during the week, in the vicinity of Arenas crater on 11 and 12 May, with a maximum value of 5 MW. The persistence of these anomalies confirms the instability of the Nevado del Ruiz volcano and confirmed that the volcanic process continues to evolve.
The gas column of steam and ash reached a height of 1700 m, measured from the top of the volcano, on May 12 The direction of the dispersion of the column was in line with the prevailing wind in the area, which, during the week showed the predominant direction towards the West, Northwest and occasionally to the South west of the volcano.

Source : SGC.


Turrialba , Costa Rica :

10.025°N, 83.767°W
Elevation 3340 m

OVSICORI-UNA reported that an explosion at Turrialba at 1140 on 16 May generated gas-and-ash emissions, though the height of the plume was not determined due to fog. Wind models suggested that the ash plume rose 3 km above the crater and drifted WNW towards Valle Central. Officials on farms 2.5 km WNW reported abundant ashfall. Sustained tremor with significant and highly-variable amplitude continued to be recorded. On 17 May gas-and-steam emissions, intermittently but frequently containing ash, were recorded by the webcam. Throughout the day volcanic tremor amplitude decreased substantially, though numerous earthquakes continued to be recorded. Ash emissions gradually ended. At 1800 the seismic network began recording a large number of very-long-period earthquake, and at around 2200 volcanic tremor with significant amplitude was detected. Seismicity remained high the next morning.



Updated 2:40 pm CNE Turrialba

According to OVSICORI-A, the Turrialba volcano shows a radical change in the pattern of volcanic seismic tremor, he was now recorded harmonic tremor continuously from 13.00
The harmonic tremor reflects the movement of fluids (gas-liquid or even magma). Despite the change in the nature of the tremors, gas emissions, steam and ash remain at a relatively low height, not exceeding 200-300 meters above the summit.
The dispersion is to the southwest. So far, the farthest place comes the ash fall reports of San Gerardo de Irazu.
In addition, the CNE established a perimeter restriction of 5 km around the crater of the Turrialba volcano, as a precaution.

The scientific-technical agencies and the CNE maintain constant monitoring of volcanic activity, as well as coordination with the Municipal Emergency Committee Turrialba (CME).

Activity at Turrialba Volcano, located some 50 kilometers east of the capital, San José, increased significantly on Thursday with constant emanations of ash and at least three big explosions.
According to the University of Costa Rica’s National Seismological Network (RSN), the first explosion occurred at 2:05 p.m. and formed a plume of gas and ash that reached nearly 1 km high.
The second, and most prolonged one, occurred at 3:46 p.m. and lasted three minutes. A few minutes later, at 4:09 p.m., a third explosion was recorded.



The column of gases and ash at about 4:20 p.m. rose to more than 500 meters above the crater and wind conditions at that time caused ash to disperse from the volcano, mostly to the southwest, RSN reported.
Ash has been reported in San José and Heredia provinces.

Turrialba Volcano has seen increased activity following explosions in late April, some of which extended for several hours. The National University’s Volcanological and Seismological Observatory of Costa Rica (OVSICORI) reported that micro-tremors and ash eruptions from the volcano have been constant since an eruption recorded at 10:07 p.m. Wednesday.
On Wednesday, the National Emergency Commission (CNE) established a 5-km restricted access area around the volcano. Entrance to the Turrialba Volcano National Park has been closed to all visitors since 2014.
In a report, CNE geologist Blas Sánchez said ash and other materials from the explosions are visible on various farms located west of the volcano. He also reported that ash is accumulating in various nearby rivers.


Source : GVP , CNE, Tico Times .


Reventador , Ecuador :

Wednesday, May 18, 2016

The volcano is maintained with high activity.
In the afternoon yesterday and earlier today were observed emission of incandescent blocks to the south and southeast flanks up to 1000 meters below the crater. In addition, he was able to observed emissions of ash and gas westward  , which reached 1,500 m.
In addition, were generated pyroclastic flows up to 1500 m below the crater edge on the southeast flank.
From 11:00 (TL) yesterday until 11:00 (TL) today, 22 explosions (EXP), 23 events long period (LP), 2 episodes of tremor emission (TRE), and 1 episode of harmonic tremor (TRA ) were recorded.


Observations emissions and ashes:
In the afternoon yesterday, gas and ash emissions were observed  to the northwest, as well as emissions of incandescent blocks to the south and southeast flanks up to 1000 meters below the crater .In the morning, a pyroclastic flow descended 1500 meters below the crater on the South – East flank. At the moment, the volcano area is cloudy.
Rain and lahars:
There was no rain in the volcano area.

This report on a daily basis will be published at 12:00 (TL). In the case of an increase or a change in the behavior of the volcano, it will immediately issued a special report.

Source : IGEPN

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