February 02 , 2017. EN. Piton de la Fournaise , Cotopaxi , Turrialba , Bogoslof .
February 02 , 2017.
Piton de la Fournaise, La Réunion:
The eruption begun last night (31/01/2017) at 7:40 pm local time continues. After falling by a factor of 2 in the early hours of the eruption, the volcanic tremor (surface eruptive intensity indicator) remains at an average level and fluctuates. On the surface this translates into fluctuations in the height of the lava fountains rising from about 20 meters high to fifty meters high (Figure 1).
Figure 1: Evolution of the RSAM (volcanic tremor and eruption intensity indicator) between 7:00 am (1:00 am UTC) on January 31 and 5:00 pm (1:00 pm UTC) on February 1 on the seismic station of Château Fort, located on the Southern flank of the volcano. (© OVPF / IPGP)
The strong deformations which accompanied the migration of the magma towards the surface during the day of January 31 stopped at the opening of the eruptive cracks.
No seismicity was recorded during the day.
Surface flows estimated from satellite data via the HOTVOLC (OPGC – Clermont Ferrand) and MIROVA (University of Turin) platforms fluctuated during the day (in accordance with the fluctuations of RSAM recorded on the seismological stations of ‘OVPF), with values between 3 m3 / s and 7 m3 / s.
This morning’s surveys carried out by the observatory on the ground and during a ULM overflight made it possible to more precisely trace the location of the eruptive vent and the lava flows (Figure 2).
Source : Ovpf
Photo : Ludovic Laï-Yu
Cotopaxi, Ecuador :
In recent weeks, there has been low outdoor activity on the Cotopaxi volcano, which is mainly characterized by the emission of gas columns. None of the monitoring parameters (seismicity, deformation, SO2) have shown any anomaly in recent weeks. However, it is possible that small phreatic explosions affect the area near the crater.
Figure 1. Gas emission from Cotopaxi, ~ 600 m above the north-western crater (S. Santamaria, IGEPN, 22/01/2017).
Over the past few weeks, visual observation conditions have varied from days completely cloudy to completely clear days. Surface activity was characterized by low gas emission energy at the crater, sometimes as much as 1 km.
Figure 2. Gas emission from Cotopaxi, ~ 600 m above the crater heading west (Maison Sincholagua, IGEPN, 22/01/2017).
Figure 3. Surface activity of Cotopaxi up to 22.01.2017. Negative values correspond to days when there was no observation in bad weather. M snc: meters above the crater (F. Vásconez, IGEPN).
In recent weeks, the seismic activity of the Cotopaxi volcano has shown no major changes compared to previous months, with less than 15 events / day. The events are mainly long period (LP) earthquakes, fluids movements associated with some volcano-tectonic (VT) events associated with fracturing (Fig. 4).
Figure 4. Daily number of Cotopaxi volcanic events up to 23.01.2017 (IGEPN).
The results of the inclinometer of the Cotopaxi volcano, Refugio station, show an almost flat pattern of deformation during the last 5 months (Figure 5). The other instruments also show a deformation of the volcano.
Figure 5. Deformation recorded by the inclinometer station Refugio of the Cotopaxi volcano, (M. Yepez, IGEPN).
Emissions of SO2
SO2 emissions have remained below 600 tonnes / day in recent weeks, with a slight gradual increase in the number of valid measurements (Figure 6). The values obtained are slightly above the level of the pre-eruptive base, defined in May 2015. No abnormalities were observed in Aura / IMO and Suomi NPP / OMPS satellite imagery (Figure 7).
Surveillance data obtained up to January 23, 2017 do not indicate any major change in the behavior of the volcano over the last few weeks. The highlight was gas emissions, which are evident in clear weather over the last two weeks. However, so far there has been no increase in SO2 flux, unlike what was observed before the 2015 eruption. It is important to note that even under present conditions the volcano could have small phreatic explosions that could be observed affecting the area near the crater. The IGEPN is very attentive to any change in the conditions presented by the volcano.
Source :Instituto Geofísico Escuela Politécnica Nacional
Turrialba , Costa Rica :
Report of the activity of the Turrialba volcano:
1 February 2017, 11:00 am in the morning.
Since last Friday, the seismic stations record a discontinuous tremor and with a variable amplitude. This signal indicates that there are movements of pressurized volcanic fluids under the volcanic building. On the webcams, there is a degassing consisting of low aerosol content. The direction of the wind is directed towards the south-west. No ash falls or sulfur odors are reported.
Source :Observatoire Volcanologique et sismologique du Costa Ricav, Université nationale
Bogoslof , Aleutians Islands , Alaska :
Current Volcano Alert Level: WATCH
Previous Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE
Previous Aviation Color Code: RED
Issued: Wednesday, February 1, 2017, 11:06 AM AKST
Source: Alaska Volcano Observatory
Notice Number: 2017/A84
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Volcanic Activity Summary: No new volcanic emissions have been detected from Bogoslof Volcano since the activity that began at 5:20 UTC, January 31 (20:20 AKST, January 30). No detectable activity has been observed in recent seismic, infrasound or lightning data. AVO is reducing the Aviation Color code to ORANGE and the Alert Level to WATCH. High winds in the region are being seen on seismic and infrasound stations making it difficult to detect smaller signals from Bogoslof. Significant ash-producing explosions could occur at any time, with no detectable precursors. Low-level activity below our detection limit is possible and may present a hazard in the immediate vicinity of the island.
Source : AVO