June 01 , 2017. EN . Piton de la Fournaise , Bogoslof , Ertaale , Turangi (Kuharua / Taupo) .

Home / Alaska / June 01 , 2017. EN . Piton de la Fournaise , Bogoslof , Ertaale , Turangi (Kuharua / Taupo) .

June 01 , 2017. EN . Piton de la Fournaise , Bogoslof , Ertaale , Turangi (Kuharua / Taupo) .

June 01 , 2017.

Piton de la Fournaise , La Réunion :

Seismicity :
In May 2017 (up to 31 May – 12 h 00 local time), the OVPF recorded a total of:
1247 superficial volcano-tectonic earthquakes (0-2 km deep) under the summit craters, 90% of which were recorded during the 17 May magma injection (1122 events);
46 deep earthquakes (> 2 km deep);
295 collapses (in the Crater Dolomieu and at the level of the ramparts of the Enclosed Fences);
31 local earthquakes (under the island, Piton des Neiges side);
2 regional earthquakes (in the Indian Ocean zone).

 Following the magma injection of 17 May 2017, seismicity gradually decreased from 40 volcanic tectonic earthquakes on 18 May to an average of 2 per day from 22 to 29 May. The day of 30 May was marked by an increase in the number of superficial volcano-tectonic earthquakes with 8 events (Figure 1).

Figure 1: Histogram representing the number of superficial volcanic-tectonic earthquakes recorded between 18 May and 30 May 2017. (© OVPF / IPGP)

 Deformation :
Following the magma injection of May 17, 2017, inflation (swelling) of the volcano resumed at a rate significantly higher than those observed before May 17, 2017 (elongation of the order of 2 mm per day between fhe stations of the summit zone, against 0.1-0.2 mm before May 17th, Figure 2).

Figure 2: Illustration of the deformation during the last twelve months (eruptions of 11-18 September 2016 and 31 January-27 February 2017 are shown in yellow and the magma injection of 17 May 2017 is represented by a black bar ). Here is shown a baseline (distance between two GPS receivers) crossing 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 with deflation of the volcano. (© OVPF / IPGP)

This acceleration of the deformations is visible both at the level of the summit zone but also in the far field, testifying to the pressurization of a superficial source but also of a deep source (pressurization of the surface reservoir located 2 km Of depth under the Dolomieu crater by a deep magma recharge).

Gas Geochemistry
The CO2 concentrations in the soil measured at the remote stations of the Plaine des Cafres and at the level of the Gîte du volcan show an early decline (Figure 3). This trend will be confirmed in the next few days.
It should be noted that a decrease in CO2 concentrations in the soil is observed on remote stations several days to several weeks before a seismic crisis.

 

Figure 3: CO2 concentration in the soil at the level of the volcano deposit between March 2016 and May 2017 (eruptions of 26-27 May, 11-18 September 2016 and 31 January-27 February 2017 are shown in red, and the magma injection of May 17, 2017 is represented by a black bar). In blue the raw data, in red the corrected data of the effects of temperature. Values ​​are normalized to the maximum value. (© OVPF / IPGP)

 Balance sheet :
A pressurization of the surface reservoir (located about 2 km deep under the Dolomieu crater) by a deep magma recharge is currently observed.
Since the recharge is rapid and already substantial, and the environnement is already well damaged, any evolution and departure of magma towards the surface can be rapid as shown by the last seismic crises of 2016-2017.

 

Source : OVPF

Photo : IPR ( Archives)

 

Bogoslof , Alaska :

Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Issued: Wednesday, May 31, 2017, 8:51 PM AKDT
Source: Alaska Volcano Observatory
Notice Number:
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Enlarged portions of May 28, 2017 satellite image of Bogoslof Island. Inset image on lower left shows pyroclastic fall and flow material emplaced over water. Some of the material appears to have been disturbed, possibly by the force of the eruption column. It is unclear if this material represents new land or material floating on the water. Also note tephra jets which are common features of many shallow submarine eruptions. The inset image in the upper right shows a weak base surge propagating from the base of the eruption column across the tuff ring. Image data provided under the Digital Globe NextView License.

 

Volcanic Activity Summary:
An short duration explosive event occurred at Bogoslof volcano at 2:42 UTC on June 1 (6:42 AKDT on May 31) and produced a small volcanic ash cloud that was observed in satellite data. Winds are transporting the cloud towards the northwest at an estimated altitude of 23,000 ft asl. The duration of the event was less than 10 minutes, and seismicity returned to low levels following the explosion.

Due to the brevity of the event, the Aviation Color Code remains at ORANGE and the Volcano Alert Level remains at WATCH.

Recent Observations:
[Volcanic cloud height] 23,000 ft asl
[Other volcanic cloud information] NWS eruption SIGMET issued.

Source : AVO

Photo : Waythomas, chris , Dave Schneider .

 

Ertaale , Ethiopie :

Few news about this volcano, I reproduce here a report of VolcanoDiscovery.

Erta Ale volcano (Ethiopia) : activity update: eruption continues, new flank lava lake .

31 MAY 2017. The activity of the volcano remains intense and continues from both the summit (lava lake in south pit) and from the SE rift zone (lava lakes and lava flows). The summit lava lake has gradually risen again, but undergoes frequent changes as the field report below describes.

L’image contient peut-être : texte

On the SE rift zone, the effusive eruption also continues strongly into its 5th month. The lava lake, which had formed above the main fissure vent since January, has been producing multiple smaller and larger lava flows around it, with the main flow feeding a growing, vast pahoehoe lava flow field expanding to the NE.

This first rift zone lake crusted over during early-mid May, but a new lava lake formed soon after at a location about 350 m to the east. At around the same time, a new breakout of lava started in early May and has been feeding a new flow field overlapping the previous one into NE direction, currently more than 1500 m long and over 500 m wide.

Source :  VolcanoDiscovery

Photos : Erta Ale’s eruption on SENTINEL 2 satellite imagery on 29 May 2017 (image: SENTINEL2 / ESA-Copernicus data; Composition / annotations: Culture Volcan) , Sylvie Malassenet.

 

Turangi (Kuharua / Taupo), New Zealand :

Earthquake swarm update

At the end of March, we reported how the swarm activity about 10 km west of Turangi (near Kuharua lava dome) had restarted with 249 locatable earthquakes occurring in the previous week.

Plot showing the magnitude vs time for the three phases

Plot showing the magnitude vs time for the three phases

That pulse of activity led to a M4.5 earthquake at 6 km depth the largest event to date in the sequence. This swarm has now moved into its third phase, starting last Friday 25 May. This third phase is like the second phase, just without the larger event. There have been 11 earthquakes over M3 in this phase, however none are over M3.5. To date there have been 2339 earthquakes located, 587 since Friday 25 May. The events are occurring between about 4 and 12 km depth and most are in the 5-9 km depth range. The Taupo Volcanic Zone is a rifting area, growing wider each year by 6-9 mm. These earthquakes are located on the western boundary of the Zone and are likely to be related to the long-term ‘tectonic’ stretching of the Zone. Several active faults are mapped in the GNS Science Active Faults database reflecting the ‘tectonic nature’ of this area. Currently, there are no indications that the earthquakes are related to volcanic activity, being located well away from the active volcanoes.

 
Map showing the location of known faults in the area
Map showing the location of known faults in the area
 

Earthquake swarms are a common feature of the Taupo Volcanic Zone. Every few years we have one in the greater Turangi area. This one has been ongoing since 13 February and now consists of three major pulses of activity, with about 20 days between them. The second pulse is the stronger with more events and the largest event to date.

Map showing the location of the events by phaseMap showing the location of the events by phase

Swarms come in a variety of forms and it is not possible to judge the future easily for them. Some have the stronger phase near the start, others in the middle and some swarms have the stronger activity at the end. We still anticipate this one will continue in the short term. As usual, we continue to closely monitor the activity.

Source : Geonet

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Comments
  • Pamela Conley
    Répondre

    Our little Bogoslof baby is on the move!!! Can’t wait to see what will happen next!!! More pictures please!!!

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