September 02 , 2015. English. Piton de la Fournaise, Yellowstone, Sabancaya, Nevado del Ruiz .

Home / blog georges Vitton / September 02 , 2015. English. Piton de la Fournaise, Yellowstone, Sabancaya, Nevado del Ruiz .

September 02 , 2015. English. Piton de la Fournaise, Yellowstone, Sabancaya, Nevado del Ruiz .

September 02 , 2015.




Piton de la Fournaise, La Réunion :

The eruption of August 24 has entered its second week and is doing well. The activity is regular and stable, as evidenced by these photos taken on Tuesday 1 September. The main eruptive cone has grown in size and yet his face constantly changing, sometimes within hours: inside of it, two separate mouths work, each containing a lava lava explodes unceasingly, because of the rising gas bubbles escaping from the magma. Each explosion is planning shreds of lava on the edges of the cone, which explains its growth but destabilizes its internal walls simultaneously. Swathes regularly collapse into the lake of lava we guess only a few meters below the lip of the cone because we see the waves regularly.




A large plume of bluish gas (mainly sulfur dioxide) emanated yesterday of the eruption, pulled down to the ground by a strong wind. The lava always flows in the tunnel at the exit of the cone and appears about 150 meters downstream. The speed is backed, but the flows continue to spread towards the foot of Bert piton rampart, their foreheads still not progressing.

Source : Clicanoo.

Photo : Drone Visite.



Yellowstone, United – States :


44°25’48 » N 110°40’12 » W,
Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

During August 2015, the University of Utah Seismograph Stations, responsible for the operation and analysis of the Yellowstone Seismic Network, reports 40 earthquakes were located in the Yellowstone National Park (YNP) region. The largest event was a small earthquake of magnitude 1.9 on August 20, at 03:34 AM MDT, located about 1 mile east-southeast of Lake, WY. No swarm activity occurred during the month of August in the YNP region.

Yellowstone earthquake activity in August remains at low background levels.



Ground deformation
GPS stations in Yellowstone continue to record little or no deformation. (click on Static Plots / Time Series)

The Yellowstone Volcano Observatory (YVO) provides long-term monitoring of volcanic and earthquake activity in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.


Source : YVO


Sabancaya, Peru :


The seismicity VTP type or volcano-tectonic proximal (less than 6 km from the crater) increased sharply reaching an average of 109 VTP / day, with a significant peak on August 28, and also an  event of magnitude M 4.8 occurred  on the same day . The proximal VTP seismicity appears to have approached the crater area in large numbers and with significant amounts.

The number of hybrid-type events in this period was stable, reaching an average of 5 HIB / day; while energy showed a significant peak of 4145 MJ on August 31




LP earthquakes rate has decreased from 71 LP / day (  Report Nº33-2015) to 57 LP / day in the period; while its energy is low. In this period, the tremors type events have decreased from 11 Tremor / day to an average of 5 Tremor / day, while the energy remains low.

The maximum height of fumaroles decreased slightly from the previous period (1200 m). We could discern whitish gas (water vapor) and sporadic emissions bluish (magmatic gases). It has not been registered thermal anomalies, or significant variation in the density of SO2 emissions.


Source : IGP Perou.


Nevado Del Ruiz, Colombia :

Internal activity level of the Nevado del Ruiz volcano
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 SERVICIO Geologico COLOMBIANO through the OBSERVATORIO VULCANOLÓGICO Y SISMOLÓGICO OF MANIZALES, informs that:




During the last week, the volcanic system showed greater instability, as evidenced by the various monitoring parameters and which was reported in the special bulletin of 28 August The recorded seismic activity was mainly associated with fluid dynamics in volcanic conduits. This activity was characterized by the recording of a large number of LP type of events (long period) and the recording of several episodes of tremor, which were associated with emissions of gases and ash in the atmosphere. The pulse of tremor, recorded today at 3:21 (local time), have an energy level higher compared to pulses of tremor saved earlier. This seismicity associated with fluid movement is mainly located in the Arenas crater and under the surrounding areas.

In addition, it is important to note the registration of an volcanotectonique type of seismicity, type of activity associated with the fracturing of the volcanic rock in the structure. Earthquakes are located in the vicinity of the volcano at depths between 0.77 and 6.77 kilometers. The maximum magnitude recorded during the week was M 1.1   (local magnitude), corresponding to an earthquake located 2.8 km southwest of Arenas crater, which was held on August 27 at 1:44 (local time) at a depth of 4.69 km. Continuous volcanic deformation show some changes.



The volcano continues to emit into the atmosphere a significant amounts of water vapor and gases, including sulfur dioxide (SO2). The gas and steam column reached a height of over 2,000 meters above the summit of the volcano, and sometimes a gray color was observed due to the presence of volcanic ash. The direction of the dispersion of the column was in harmony with the wind regime, which remained mainly to the northwest sector of the volcanic edifice.

In recent weeks, the the SERVICIO Geologico COLOMBIANO through the OBSERVATORIO VULCANOLÓGICO Y SISMOLÓGICO OF MANIZALES has, in addition to research and volcanic monitoring, initiated important socialization process of the technical information in certain municipalities of the departments of Caldas and Tolima, on the front of the watershed of the volcano Nevado del Ruiz, to continue to contribute to the social appropriation of scientific knowledge and geo volcanology. This social work is needed to ensure the well-being of communities and save lives. We note with concern the lack of interest and low participation of certain authorities, and broader sectors of the community in some municipalities for these efforts. Recall that risk management is everyone’s responsibility.

While the volcano Nevado del Ruiz remains to this day in a yellow level of activity, it is possible that additional changes occur in the behavior of volcanic activity.

Source : SGC.

Photos : SGC  ( 01/09 et 19/07 /2015 )

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