July 07 , 2017. EN. Copahue , Nevados de Chillan , Reventador , Poas , Turrialba , Rincon de la Vieja .

Home / blog georges Vitton / July 07 , 2017. EN. Copahue , Nevados de Chillan , Reventador , Poas , Turrialba , Rincon de la Vieja .

July 07 , 2017. EN. Copahue , Nevados de Chillan , Reventador , Poas , Turrialba , Rincon de la Vieja .

July 07 , 2017.

 

Copahue , Chile :


During this period, seventy-six (69) seismic events, of which twelve (12) were classified as volcano-tectonic (VT), associated with fracturing processes of rigid materials were recorded. Similarly, fifty-seven (57) events associated with fluid dynamics within the volcano, classified as long period (LP), with maximum displacement values ​​(DRC) of 2.1 cm2 were recorded.
With regard to VT seismicity, the local magnitudes (ML) were less than or equal to M 1.8. The highest energy event was located in the North-Northwest, 5.9 km from the El Agrio crater with a depth of 5.3 km.
Throughout the period a constant amplitude constant tremor signal, associated mainly with the exhaust from the El Agrio crater, was recorded. This signal provided fluctuating DRC displacement values ​​in the range of 2.0 ± 0.5 cm 2. The dominant frequencies are distinguished in two predominant bands, one marked at 0.6 Hz and the other bandwidth ranging from 1.1 to 1.7 Hz.


Since June 28, it has been recorded punctually increases in the signal of continuous tremor. These increases are associated with explosions in the crater, of low intensity level, which were accompanied by small increases in ash emissions. The acoustic series associated with this phenomenon are less than or equal to 0.5 Pascals, a value considered to be low.
According to the data obtained from three (3) GNSS stations which measure the deformation of the volcano surface, small amplitude displacements for the horizontal and vertical components are observed. In turn, the control line through the volcano was stable.
The IP cameras installed in the vicinity of the volcano showed constant degassing of the active crater (El Agrio) with constant and vigorous ash emissions over several days. The main emission column was recorded on 27 June, which was directed towards the east, with a maximum height of 800 m.
No sulfur dioxide (S02) emissions in the atmosphere adjacent to the volcano sector have been reported, according to data published by the Ozone Monitoring Instrument (OMI) Sulfur dioxide group (http: //so2.gsfc.nasa.gov/) and NESDIS, (http://satepsanoine.nesdis.noaa.gov).
No thermal alerts were reported on the volcano, according to data processed by Mirova (http://www.mirovaweb.it/) and MODVOLC (Http://modis.higp.hawaii.edu/).

The very low frequency activity that began on 29 May and associated with a possible rise of magmatic material inside the volcanic ducts ceased on 14 June, generating instability of the surface hydrothermal system, with emissions of ash. This activity could evolve to higher levels with the possibility of minor explosions affecting the area near the active crater. Therefore, the Copahue volcano remains at the technical alert level:

YELLOW LEVEL: changes in the behavior of volcanic activity – probable time for eruption: weeks / months.

Note: It is recommended to apply preventive restrictions on the access of a zone near the crater with a radius of 1000 m.

 

Source : Sernageomin

 

Nevados de Chillan , Chile :

During the period, 790 seismic events were recorded, of which 69 were classified as volcano – tectonic events (VT), in relation to rock fracturing processes, with maximum local magnitudes (ML) of M 1.7 . The biggest earthquake was located 5 km east-south-east of the active crater, at a depth of 9.4 km. There were also recorded 721 events associated with fluid dynamics within the volcanic edifice, of which 683 were cataloged as long-term (LP) events with maximum displacement values ​​(DRCs) of 216 cm2. In addition, tremor events were recorded with reduced displacement values ​​(DRC) of 28.7 cm 2. Lastly, there were recorded 3 long – period events , »Tornillo » type (TO) , related to movements of magmatic and / or hydrothermal fluids in magmatic conduits with high impedance contrast characteristics, of which the most significant event Reduced displacement values ​​(DRC) of less than 1.0 cm2.

Intermittent explosions were recorded between 20 and 22 and 25 and 26 June. The recorded pulses had characteristics associated with phreato – magmatic explosions. The explosion of greater energy was recorded on June 25 with reduced displacement values ​​of 77 cm2.

The images obtained by the cameras installed near the volcanic complex showed explosions around the currently active craters at maximum heights of 200 m. With unfavorable climatic factors, many signals with explosion characteristics, could not be seen through IP cameras.

Similarly, according to the information obtained from 5 GNSS stations that measure the deformation of the volcano, variations of low amplitude have been observed, both in the horizontal and vertical components. The control lines that cross the volcano have identical variations, suggesting instability in the form of deformation. The data of the two inclinometers showed no variations due to changes in the morphology of the complex.

 

Sulfur dioxide (SO2) emissions recorded by Chillan Station (DOAS), located 2.6 km southeast (SE) of the active crater, have a monthly mean value of 1598 ± 1548 t / day and a maximum value Of 2529 t / day, reported on June 18th. S02 emissions are at moderate levels for this volcano.
No emission of sulfur dioxide (SO2) into the atmosphere in the volcanic complex sector has been reported, according to data published by the Ozone Monitoring Instrument, OM Sulfur Dioxide Group (http: // So2.gsfc.nasa.gov/) and NESDIS (http://satepsanoine.nesdis.noaa.gov).
No thermal alerts were reported in the volcanic complex based on the data processed by Mirova (http://www.mirovaweb.it/) and MODVOLC (http://modis.higp.hawaii.edu/).

The volcanic complex exhibits a transitions behavior between explosive and non-explosive periods that was characteristic of the process begun in 2016. It is suggested that the interaction between the surface hydrothermal system and the activity of a magmatic body has decreased, generating fewer explosions, with medium to low emission column heights. However, in view of the dynamic behavior of the system, it is possible to see the appearance of new explosions of similar size, or even greater than those recorded. Therefore, the level of technical volcanic alert remains at the level:

YELLOW LEVEL: changes in the behavior of volcanic activity – probable time for eruption: weeks / months.

Note: It is recommended to apply preventive restrictions on the access of an area near the crater with a radius of 3 kilometers.

 

Source : Sernageomin

 

Reventador , Ecuador :

SUMMARY OF VOLCANO ACTIVITY Thursday 6 July 2017.

The volcano persists with high and continuous activity. Most of the time, the volcano remained covered. Between the clouds it was possible to see a small pyroclastic flow down the east flank.

TECHNICAL APPENDIX AND OBSERVATIONS

Seismicity:
Since 11:00 am (TL) yesterday until 11:00 am (TL) today, 4 episodes of harmonic tremor (TRA), 31 events of long period (LP) and 28 explosions (EXP) were recorded.
Observations, emissions and ash:
Most of the time, the volcano remained covered. Between the clouds it was possible to see a small pyroclastic flow that descended on the eastern flank about 800 meters below the summit.
Rains and lahars:
No light rain was recorded.

 

GENERAL INFORMATIONS
The present report on a daily basis will be published at 12.00 (TL). In the event of an increase or change in the behavior of the volcano it will be immediately published a special report.

Source : IGEPN

Photo : P. Taschler

 

Poas , Turrialba, Rincon de la Vieja , Costa Rica :

Activity report of the Poas, Turrialba and Rincon de la Vieja volcanoes, 6 July 2017, updated at 11:15.

Volcano Poas:
The tremor of moderate amplitude which had been recorded for two hours yesterday stopped today at 4 o’clock, leaving a weak signal of tremor of very small amplitude. Several volcano-tectonic (VT) earthquakes, associated with the breaking of the rock and located in the vicinity and to the southwest of the active crater, continue to be recorded. The emission of plumes of vapor, magmatic gases and aerosols of fine particles (liquid or solid) occurs in passive (non-explosive) form. During the morning, the fumarolic mouth A (Boca Roja) intermittently emitted moderate quantities of gray-brown ash for short intervals of time.

 


The plume rose vertically between 200 and 600 meters above the crater and was dispersed by the prevailing winds towards the West-South-West and the South. A strong odor of sulfur has been reported in Alajuela: Central Canton, Grecia, Zarcero, Naranjo, as well as in Heredia: Barva and San Rafael.

Turrialba Volcano:

The Turrialba presents a fluctuating volcanic tremor signal with low amplitude and frequent low frequency volcanic earthquakes (LF), both associated with the circulation of fluids (water, gas, magma). The emission of a bluish plume, rich in water vapor, magmatic gases and aerosols (very fine liquid or solid particles) was observed in passive form. The volcano sporadically emitted moderate amounts of ash, forming a plume about 100 to 200 m high above the crater, from noon yesterday to early this morning.

An incandescence continues to be observed during the night in the western crater, through the webcams.
The wind dispersed the plume northwest, west, southwest. The residents reported very light ash falls at San Jose: Coronado; As well as in Heredia: Barva and San Rafael.

Rincón de la Vieja Volcano:
No significant activity has been reported in the past 24 hours. The webcam located 3.8 km north of the volcano, showed no particular event around the crater.

 

Source : Ovsicori

Photos : Blas Enrique Sánchez ,

 

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