August 06 , 2017. EN. Piton de la Fournaise , Planchon-Pétéroa , Poas , Turrialba , Ruapehu.

Home / blog georges Vitton / August 06 , 2017. EN. Piton de la Fournaise , Planchon-Pétéroa , Poas , Turrialba , Ruapehu.

August 06 , 2017. EN. Piton de la Fournaise , Planchon-Pétéroa , Poas , Turrialba , Ruapehu.

August 06 , 2017.

 

Piton de la Fournaise , La Réunion :

Activity report on Saturday, August 5, 2017 at 3:30 pm (local time).

The eruption begun on July 14 at 00:50 local time continues. The volcanic tremor (indicator of surface eruptive intensity) continues its gradual decline (Figure 1).

 

Figure 1: Evolution of the RSAM (volcanic tremor and eruption intensity indicator) between 00:00 (20h UTC) on July 14th and 15h00 (11h00 UTC) on August 5th on the RVL seismic station, located on the flank South of the volcano. (© OVPF / IPGP)

In the field, the activity is now mainly in lava tunnels with some visible surface resurgences on a small spatial extension. Gas emissions remain high.

– No earthquakes have been recorded in the past 24 hours.
– The trend towards a slight recovery in inflation observed over the past few days on deformation sensors, in particular GPS, is confirmed.

 

Estimations carried out using satellite methods via the HOTVOLC platform (OPGC – Clermont Ferrand) report minimum flows between <1 and 2 m3 / s.

Source : OVPF

Photo : N. Beuchat

 

Planchon-Peteroa , Chile :

During the period evaluated, a total of 1598 earthquakes, of which sixty-four (64) were associated with processes of fracturing of rigid materials called volcano tectonics (VT) with a maximum local magnitude (ML) of 1.7, for an earthquake located 2.4 km northwest of the active craters, at a depth of 6.7 km were recorded. For the most part, these events were located north of the crater of the volcanic edifice, distances up to 5 km and predominant depths between 4 and 7 km.
For events related to fluid dynamics (of the long period type, LP), 1,500 events were classified with maximum reduced displacement values (DRc) of 2.5 cm2.

Résultat de recherche d'images pour "planchon peteroa"

The images of the cameras showed the presence of small degassings of little energy and whitish coloration that do not exceed 250 m above the level of the active craters of the volcanic complex.
From the data obtained by three (3) GNSS stations, which measure deformation on the volcanic complex, there were minor variations, both in the horizontal and vertical movements of the monitoring stations. As regards the control line that runs through the complex from north to south, it is in line with the stability of the stations, which shows small changes. On the other hand, the data provided by one (1) electronic inclinometer, installed on the complex, also show no modifications related to the morphology of the volcano.

No anomalies were reported in sulfur dioxide (SO2) emissions to the atmosphere in the volcanic complex area, based on data from the Ozone Monitoring Instrument (OM), Sulfur dioxide (Http: //so2.gsfc.nasa .gov /) and NESDIS (http://satepsanone.nesdis.noaa.gov).
No thermal alerts were reported in the area associated with the volcanic complex according to data published by the Middle Observation InfraRed of Mirova volcanic activity on its website (http://www.mirovaweb.it/).

The recorded seismicity indicates that the volcanic system continues with an internal dynamics which facilitates the possibility of developing a direct interaction between the magmatic system and the surface hydrothermal system with the generation of more or less explosive activities which, first of all, would affect the zones Close to active craters and / or low to moderate ash emissions. Hazardous area is therefore considered to be within a radius of 1 km around the active crater area and it is recommended that access be restricted. The level of volcanic alert is maintained at the level:
YELLOW LEVEL: Changes in the behavior of volcanic activity – Probable time for eruption: WEEKS / MONTHS.

 

Source : Sernageomin.

Photo : Nicolás Lecaros , vei.de.

 

 

Poas , Turrialba , Costa Rica :

Report on the activities of the Poás and Turrialba volcanoes.

Volcano Poas: activity over the last 23 hours.

 

L’image contient peut-être : montagne, nuage, ciel, nature et plein air

Eruption recorded on the Poás volcano, as observed from the r.s.c. surveillance cameras the 01/08. The eruptive column is scattered to the west in the direction of the wind.

During the last 23 hours, the Poás volcano showed little eruptive activity although degassing was maintained. There are no reports of falling ash or sulfur odors. Some recordings of a moderate tremor are maintained and the wind drives gases and steam, mainly towards the West.

Volcan Turrialba: activity over the last 23 hours.

 

L’image contient peut-être : 1 personne, nuage, montagne, ciel, plein air et nature

The Turrialba volcano exhibited low-amplitude tremor recordings. No ash emissions were detected during the visibility window. The wind carries gas plumes mainly west and southwest.

The OVSICORI-UNA remains vigilant on seismic and volcanic activity.

Source : Ovsicori

 

Ruapehu , New Zealand :

Mount Ruapehu Crater Lake (Te Wai-a-Moe) under the microscope.

…/…

Although it is now almost 10 years since the last eruption from the Crater Lake (Sept 2007), Mount Ruapehu remains one of our most active volcanoes. Small eruptions only affect the summit plateau around the Crater Lake, however the larger ones can generate lahars down the slopes. These larger, lahar generating eruptions occur on average about once every 7 years and can impact the ski fields. So, remembering Ruapehu is an active volcano, it is a good idea to check out the hazard information before heading to the skifields. There are hazard posters and video clips you can check out.

GeoNet monitors Ruapehu volcano and its Crater Lake. The monitoring includes seismic, acoustic, GPS sensors around the volcano, gas flights and sampling of the Crater Lake. The temperature and water level of the lake are also monitored by datalogger. Crater Lake is now cool, currently the lake temperature is 19 °C. The temperature of the lake typically ranges from over 38 °C to less than 16 °C.

 

 

An analysis of the lake temperature data since 2009 when we installed a datalogger shows that for 5% of the time it is warmer than 38 °C and another 5% it is less than 16 °C. The median temperature is 24 °C. Looking at the longer term Crater Lake temperature data, collected from lake visits since 1950, the behaviour is similar. Those data show that for 5% of the time it is warmer than 47 °C and another 5% is cooler 14 °C. The higher temperature reflects the volcanic unrest and eruptive activity of the 1960’s-1980’s. The median temperature was 28.0 °C.

Research on the eruptive history of Ruapehu through the Crater Lake has shown that the probability of an eruption increases when the lake is significantly warmer or cooler than the median temperature range. Eruptions have been significantly more frequent when the lake was hot rather than cold. Despite the current lower lake temperature, the likelihood of an eruption remains low: in the 10 years since the last eruption the lake has cooled seven times to below 16 °C and heated six times to over 38 °C with no eruptions.

 

 

Plot showing the temperature of Ruapehu Crater Lake: the median and upper/lower 5% boundaries are shown.

The GeoNet monitoring of the volcano and Crater Lake does however indicate the volcano is alive. The gas flights continue to record volcanic gases (CO2 has ranged 100-1800 tons/day, while SO2 has ranged 50 to 200 tons/day during the last 5 years). The primary chemical indicators show there are as less volcanic fluids present. The seismic energy is also low at Ruapehu, with very little volcanic tremor being present.

GeoNet continues to monitor as it always has. Sounds like it is a good time to go ski an active volcano, but don’t take your eye off it and remember what to do should you hear the sirens (go to higher ground if in a valley).

 

Source : Geonet

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