January 07 , 2017. EN. Nevados de Chillan , Copahue , Piton de la Fournaise , Bogoslof , Sabancaya .

Home / Alaska / January 07 , 2017. EN. Nevados de Chillan , Copahue , Piton de la Fournaise , Bogoslof , Sabancaya .

January 07 , 2017. EN. Nevados de Chillan , Copahue , Piton de la Fournaise , Bogoslof , Sabancaya .

January 07 , 2017.

 

Nevados de Chillan, Chile :

(16 to 31 December).
  YELLOW activity level: changes in the behavior of volcanic activity.

1,092 seismic events, of which one hundred and two (102) were related to fracturing processes of rigid materials called volcano tectonic earthquakes (VT) with a maximum local magnitude (ML) of 2 were recorded, 4 associated with an event located at 1 , 7 km West-Northwest (WNW) of the active crater with a depth of 4.5 km. In addition, nine hundred and ninety (990) earthquakes called long-term (LP), related to the dynamics of fluids inside the volcano were recorded. The LP earthquake of greater magnitude was recorded on 27 December at 19:39 (local time) with a maximum local magnitude (ML) of 2.3 and a reduced displacement (RDC) of 40.9 cm2.

 

Nevados de Chillan - 05.01.2017 / 20h10 locale - photo Sernageomin

The explosive activity shown during the first half of December continued, recording fourteen (14) explosions in this period, which were mainly associated with fluid seismic events (LP and tremors – TR), the one that occurred on 28 December at 10:55 (local time) deployed the most energy with a reduced displacement value (RDC) of 35.8 cm2.

On 27th December an overflight of the Nevados of Chillan volcanic complex  was carried out, where, thanks to a thermal camera, it was possible to measure a temperature lower than 50 ° C in the zone of active craters.

According to the data obtained by the four (4) GNSS stations and two (2) inclinometers to control the deformation of the volcanic complex, small amplitude variations in the horizontal and vertical components of the GNSS stations were observed which did not exceed 0, 6 cm / month, as well as lower inclinations that showed no deformation with trends related to the volcano’s internal activity, showing only a small amplitude and variations compatible with climatic effects.

 

nevados de chillan

DOAS (Differential Optical Spectrometry) equipment, Chilian Station, located 3 km East-Northeast (ENE) of the active crater, did not provide any registration data this month.
No anomalies were reported in sulfur dioxide (SO2) emissions to the atmosphere in the volcanic complex area according to IMO data (http://so2.gsfc.nasa.gov/) and NESDIS (http://satepsanone.nesdis.noaa.gov).

A thermal alert was recorded on the volcanic complex during the month, associated with the occurrence of an explosion, with a volcanic radiative power (RVP) of 2 MW, considered to be moderate, according to data published by the Middle InfraRed, Observation of volcanic activity (Mirova) on its website (http://www.mirovaweb.it/) based on remote sensing of hot spots.

 

nevados de chillan

The persistence of fluid dynamics events added to the recording of sporadic explosions suggests that the volcanic complex system is still unstable. In this context, and due to the low power of the explosion episodes associated with the low temperatures noted in the last flights, there is the probability of new phreatic explosive phases and / or a greater phreatomagmatic intensity of the actives craters  . Thus, the volcanic alert level remains yellow, and is considered as a high-risk the area within 3 km of the active crater.

Source : Sernageomin

 

Copahue , Chile :

16 to 31 December.
The level of activity of the volcano is at the level:
YELLOW LEVEL: changes in the behavior of volcanic activity.

During this period, 899 seismic events, five (5) of which were classified as volcano-tectonic (VT) associated with fracturing processes of rigid materials were recorded. Similarly, eight hundred and fifty-one (851) events associated with fluid dynamics within the volcano, identified as long-period earthquakes (LP), and forty-three (43) earthquakes identified as very long-period earthquakes (VLPs) were noted .
With regard to seismic activity of type VT, the local quantities (ML) are less than or equal to M 1.5. The top energy event (December 24th) was located on the north-northeast flank (NNE), 13 km from the crater El Agrio with a depth of 6 km.

 

copahue

In relation to LP events, these showed reduced displacements of less than 2 cm2, whereas VLP events showed reduced displacements of less than 4 cm2. These events were located around the active crater.

Throughout the recording period, a constant, low amplitude tremor, mainly associated with gas exhaust as well as particle emissions (ash) from the El Agrio crater, exhibited DRC values oscillating around 1, 5 cm2. The dominant frequencies were concentrated in a bandwidth ranging from 1.2 to 2.1 Hz.

On 27 December an overflight of the Copahue volcanic complex was carried out. As the flyovers of 02/09 and 2/11 2016 no acid lake was observed inside the crater, showing a decrease in the hydrothermal surface of the system. With regard to the pyroclastic cone situated in the center of the active crater and with respect to the preceding overflights, a greater accumulation of particulate material and the opening of a larger diameter than the last flyover is appreciated. The temperature of the emitted gases measured by the thermal camera was close to 300 ° C., a value lower than those measured previously.

 

copahue

From the data obtained from three (3) GNSS stations, which measure the deformation of the volcano surface, it was observed that the horizontal distance between the monitoring stations, crossing the volcano, had very small variations On all axes, near a shortening speed of 0.3 cm / month.
The emission of sulfur dioxide (S02) recorded on the Copahue volcano by the DOAS (Triplets Spectrometry for Differential Optical Spectrometry) team, located 5 km east-northeast (ENE) of the active crater, have an average value of 479 ± 127 t / d and a maximum value of 585 t / d, noted on 15 December. The average flow rate is considered low for this volcano.
The IP cameras installed near the volcano recorded a constant degassing of the active crater (El Agrio), characterized mostly by a gray color, showing the presence of particulate matter.
No anomalies were reported in emissions of sulfur dioxide (S02) to the atmosphere in the volcano sector.
Two (2) thermal alerts were reported, associated with the volcano during the second fortnight, the main one was recorded on 22 December with a 5 MW volcanic radiative power (PRV), which is considered low according to the published data By Middle InfraRed Observation (Mirova) on its website (http://www.mirovaweb.it/).

copahue

The above monitoring parameters indicate that the continuous activity is dominated by the appearance of a restricted type of strombolian surface activity within the El Agrio crater associated with the slow rise of a small volume of magmatic material and / or its degassing in an open volcanic system interacting with the shallow hydrothermal system. It is emphasized that this type of activity can continue in a long oscillating manner, without excluding specific increases related to small phreatic explosions and / or weak strombolian activity in the active zones surrounding the crater. Therefore, it is considered high-risk area within 1.5 km of the El Agrio crater and consequently it is recommended to restrict access to this area. The level of volcanic alert stays in yellow.

Source : Sernageomin

Photos : Archives

 

Piton de la Fournaise , La Réunion :

Activity Bulletin of Monday, January 2, 2017

Seismicity
After a month and a half of relatively low volcano-tectonic activity under the Piton de la Fournaise, summit seismicity resumed in mid-December (with a low seismicity of 2-3 events per day on average and a peak on 23 December with 10 earthquakes).

Thus, during the month of December 2016, the OVPF recorded in total:
36 superficial volcano-tectonic earthquakes (0 to -2 km below the surface) under the summit craters;
3 deep earthquakes (> 2 km deep) under the eastern flank of Piton de la Fournaise;
468 collapses (in the Crater Dolomieu, at the level of the wall of the Enclosure Fouqué and on the flow of September 2016);
26 local earthquakes (under the island, Piton des Neiges side);
75 regional earthquakes (in the Indian Ocean zone).

 

Summary of superficial volcano-tectonic seismicity at Piton de la Fournaise from 18 September (end of last eruption) to 31 December 2016. (© OVPF / IPGP)


Deformation

Following its halt on 6th October, headline inflation resumed on 12 December at rates similar to those recorded before the eruptions of 2015 and after the eruptions of 2016 (elongation of 0.5-1 mm / day).

Illustration of deformation during the last six months (eruptions of 26-27 May and 11-18 September 2016 are shown in yellow). (Left) Here is shown a baseline (distance between two GPS receivers) crossing the Dolomieu crater from north to south (in black the raw data, in blue the smoothed data over a week). A rise is synonymous with elongation and therefore swelling of the volcano; Conversely, a decrease is synonymous with contraction and therefore deflation of the volcano. (© OVPF / IPGP)

The more distant stations (witnesses of the influence of deeper pressure sources) from the base of the cone or the edge of the Enclos Fouqué also continue to show signs of inflation with an acceleration since 12 December.

piton

Gas Geochemistry

Summit fumaroles : The atmospheric excesses of CO2, H2S and SO2 are generally low.
Concentration of CO2 in the soil at remote stations (zone outside Enclos Fouqué): Significant increase in December of the CO2 concentration in the soil at the site of the Gîte du volcan. In the farther field, data from the permanent station of the Plains of Cafres (site of the observatory) also show an increase since December while concentrations remain low on the permanent stations of Piton Bleu (Bourg-Murat) and the Plain of the Palmistes.

Bilan

Signals recorded since mid-December show that deep deposits of magma are still present and are currently stored at about 2km below the Dolomieu crater. Nevertheless, as has been observed several times in 2016, such phases of inflation and seismicity recovery may stop very quickly and not lead to a medium-term eruption.

Source : OVPF

Photo : C Chapelet

Bogoslof , Aleutians Islands , Alaska :

53°55’38 » N 168°2’4″ W,
Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Eruptive activity at Bogoslof continues. There have been no further ash emissions since the explosion yesterday at 13:24 AKST (22:24 UTC) therefore AVO lowered the Aviation Color Code to ORANGE and Alert Level to WATCH earlier today. The event yesterday lasted for about 5 minutes as measured by seismicity and produced a cloud that rose as high as 35,000 ft asl, quickly detached from the volcano and drifted north-northwest as seen in satellite images. This event was first detected by seismic stations located on neighboring Umnak Island and by lightning strikes detected by the World Wide Lightning Detection Network. The activity was also seen on more distant infrasound (pressure) sensors. In addition, there were several pilots who reported observations of the cloud as it tracked north.
bogoslof

Photograph of Bogoslof’s eruption plume, January 5, 2016, as viewed from a flight out of Dutch Harbor.

While some explosions during this eruptive sequence have been preceded by seismic activity detected on stations on Umnak Island, other explosions have had little or no detected precursory activity. The event yesterday was not preceded by any detectable activity on the available seismic stations. Since the event yesterday, seismic activity has been quiet. There was an uptick in wind noise seen late last night but has since quieted down.

Yesterday’s event was the fourth explosion in the past week and eleventh explosion that AVO has detected since December 20. The explosions have occurred every 1-3 days.
Source : AVO

Photo : Wright, Kevin

 

Sabancaya , Peru :

The seismicity showed moderate activity with the appearance of explosions, earthquakes and volcanic tremors associated with fluid movements (EXP, TRE, LP) occurring in number and in energy equal to the previous week. However, he observed a decrease in events associated with movement and / or magma uplift (HIB).

sabancaya


The eruptive columns of gas and ashes reached the 4,500 meters above the crater, spreading over a large radius of more than 40 km in the direction of the South-East, South, North and North-West of the volcano.
The deformation to the northeast of the crater was 4 mm.
The volcanic gas flow (SO2) recorded a maximum of 2700 tons / day. No significant variation.

Source : IGP

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