August 29, 2015. English. Sabancaya, Piton de la Fournaise, Cotopaxi .

Home / blog georges Vitton / August 29, 2015. English. Sabancaya, Piton de la Fournaise, Cotopaxi .

August 29, 2015. English. Sabancaya, Piton de la Fournaise, Cotopaxi .

August 29, 2015.

 

 

Sabancaya, Peru :

 

Updated summary of the principal activity observed from 25 to 28 August

This is a special report, following the intense seismic activity that occurred in the area near the Sabancaya in the last 24 hours. Earthquakes that are reported in this report are located 6 km north and north – east of the crater. This is the first time since 2013, that the epicenters are so near the crater in large numbers.

Sabancaya

The number of earthquakes VTPS or « proximal volcano-tectonic«  have significantly increased, reaching an average of 92 VT / day, much higher than the value of the previous period (23 VT / day)  .There has been  a peak of 281 VTP on August 28th .The energy also rose sharply, mainly due to the occurrence of an earthquake magnitude  4.8 ML registered on August 28 at 4:11 UTC. The location of these earthquakes is very near the crater in distances .


The number of LP type events (associated with the passage of fluids) fell for this report, to an average of 57 LP / day less than the previous period (71 LP / day). In addition, energy remain low.

The number of hybrid events (associated with magmatic material rising) remained at a low average, scoring five HIB / day. However, it is observed that increased energy on August 28, reaching 225 MJ.

-The Type of seismicity VT or volcano tectonic, rose sharply in this report, to achieve a rate of 173 VT / day, while in the previous period, it was recorded only 48 VT / day.

-The Tremor type events for this report, saw their rates decrease to 05 Tremor / day. The energy of these events is low.

During the early hours of August 28, 53 earthquakes LP type and  06 hybrid earthquakes are recorded. Later, at 4:11 p.m. UTC, the most important type of event VT, with a magnitude of M 4.8, was recorded. Then occurred many type of VT earthquakes, reaching the peak of 540 in less than 11 hours.

sabancaya

During this period, the type of VT seismicity is mainly distributed very close to the volcano area, which is called VTP (less than 6 km from the volcano). 3 events were recorded on August 28, of significant magnitude, the first , M 4.8 at 4:11 UTC, the second , M 3.5 at 4:18 UTC and the third,  M 3.4 at 4:17 UTC. Depths are low and vary between 6 and 9 km. On August 28, were recorded  84 VTS events with magnitudes between 1.0 and 4.8 ML and shallow depths, between 4 and 10 km.

 

Source : IGP /OVS

Photos : Andina .com , andeantrails.co

 

Piton de la Fournaise, La Réunion :

 

The current eruption continues.Work on GNSS network of OVPF  allowed to  the OVPF team to pass on the eruption site and collect new samples on 28 August.
Two cones are built in eastern Rivals crater on the lowest part of the cracks. The biggest (upstream) projects fountains at about thirty meters high. Both cones are occupied by a small lava lake.
At the foot of cones, lava circulate in tunnels and appears further downstream. A large flow was visible yesterday after noon. The images of the camera Piton Bert confirm that this flow was still active throughout the night.

 

piton

The flow front has not changed for several days.
The intensity of the tremor increased yesterday. This morning it remains at fairly high level.
An aerial survey should be conducted in the day.

Source : OVPF

Photo : Alexandre Belucat.

 

 

Cotopaxi, Equateur :

 

Constant emission of ash and gas and increase in shallow earthquakes of rupture.

On August 26 the volcano had a continuous emission of ash with a few breaks, which are mainly oriented to the NW. The cloud of ash, steam and volcanic gases passed the Cordillera Occidental and there are reports of minor ash fall in Santo Domingo and even in some remote areas. Since the beginning of the continuous tremor on the night of Saturday, August 22 at 9:41 p.m., there were very few breaks in the last six days.

The ash fall reports cover vast areas westsouthwest of the volcano. They reach thicknesses up to millimeter levels. The last sighting was confirmed by the mayor of Sigchos in the province of Cotopaxi, speaking of damage to livestock, crops outdoors and in greenhouses. During the last 36 hours, the ash fall has left a very dense film of ash on Cotopaxi volcano monitoring stations.

cotopaxi

 

During analysis of the ash falls related to explosions on August 14, it was calculated an approximate volume of 56 000 m3 of volcanic material deposited. Then, in the period from August 15 to 21, another analysis of falls ashes detected by the network of IGEPN estimated that 19,500 m3 were expelled during those six days and was mostly fell back to the north-west .

On 18 and 26 August, the volcano overflights were made to conduct thermal monitoring the volcano using an infrared camera. The results obtained indicate that temperatures of the emissions between the two dates indicated significantly increased to reach about 150 ° C , on images taken on  August 26, in addition it has been found that temperatures ( TMA = apparent high temperature ) observed in the different sectors of the volcano are higher than those observed on images on August 18 .

Source : IGEPN

Photo : José Luis Espinosa Naranjo .

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