October 11, 2015. EN. Piton de la Fournaise, Sinabung, Kilauea .

Home / blog georges Vitton / October 11, 2015. EN. Piton de la Fournaise, Sinabung, Kilauea .

October 11, 2015. EN. Piton de la Fournaise, Sinabung, Kilauea .

October 11, 2015.



Piton de la Fournaise, La Réunion :


The current eruption continues.
On the morning of Sunday, October 11 (7:45 in the forty ninth day of eruption) eruption which began on 24 August is still ongoing. At 7:45 this morning the sky is (like yesterday) completely clear from the coast to the summit of Piton de la Fournaise.
The level of activity remains high and comparable to that in previous days. However a slight tendency to decrease in activity was recorded in the last days (see detailed report of October 9 below).

Geophysical and geochemical indicators showed since 1 October (date of the last bulletin) some evolutions.
Since September 24, 2015, the seismicity moves up. This trend is still present as shown in Figure 1 on the Station Rivals (10% increase). Note down slightly early in the day (we will look if it is confirmed that WE). The increasing trend is not as significant on Bory and Dolomieu South or even on other network stations.



Figure 1: RSAM (seismic intensity) recorded by the Station Rivals since the beginning of the eruption. 1-5 compartments are described in the bulletin of 24 September 2015. The red line is the date of the last full report issued by the OVPF. The compartment 6 is the increasing trend observed since September 24 which is ongoing.

The trend of low deflation observed since September 27 was confirmed both in summit area, at the base and at a greater distance. This trend is still quite sensitive. Here we measure the variation of distance (called baseline) between summital GNSS stations, stations at the base of the central cone and stations at a greater distance (sometimes outside of l’Enclos). Deflation measured on the last 10 days is lower than 5 mm.


The gas flow measurements were possible with the return of warm weather (the weather limiting optical measurements).
After a period during which we recorded significant flows of CO2 in soil values have decreased significantly since October 4th.
Flows of SO2 remain constant in the plume and at the top.
We note a significant increase in water vapor at the top of the volcano.

The flow measurements are made mainly at a time from the luminescence of Modis and MSG satellite images, and at the same time by applying a law of correlation between the flow of and the lava flow. Of course, the bad weather had significantly reduced these measures for two weeks. Since the return of good weather we observed a peak of lava flow equal to 11m3s 1on October 4 and then return in the range of 5 and 10 m3s-1 as before.



In summary, geophysical and geochemical indicators remain at a high level with a slight downward trend for those who are related to a pressurization of the volcano. The hypothesis formulated following this at a month and half of eruption is that deep fluids (gas and magma) arrive in the upper part of the volcano and at the surface (at least for the gas certainty) as puffs (as cycles in the gas flow and in the strains).


On the eruptive site:

Benefiting from the return of fine weather we could observe the eruption from the eruption Site every day of the week from Tuesday, October 6.
The cone is still imposing. Our estimates of height (about 30-35 meters) have been confirmed by measurements made by topography (daily 06.10.2015).

The morphology of the lava lake has evolved again. While in previous observations, a perfectly circular lake upstream and downstream a small mouth were visible, both wells are one with a general geometry of a calbasse.

Wednesday, October 7th in the evening the cone is partially breaking, creating a breach 5 to 7 meters high in its upper part. A flow of lava escaped from it.
The gas reaches the surface of the lake in the form of large bubbles which propel lava packets above and on the edges of the cone. It is these bubbles which release the gas of plume   always rich in SO2 but less rich in water vapor (white plume least).

The flows are mainly composed of smooth lava (pahoehoe) issued by ephemeral vents present on the area of lava field cooled at the surface (tunnels). What is notable is that a very large part of the field is covered by these type of pahoehoe flows, from the foot of the vent until more than two and a half kilometers downstream , burning vegetation at the foot of Piton Bert. Furthermore, at the location of many ephemeral mouths the accumulation of lava constituted some morphology of hornitos.


Source : OVPF

Photos : Arnaud Barrey , Frederic Leveneur , Ben . ( Fournaise info)



 Sinabung, Indonésie:

3.17°N, 98.392°E
Elevation 2460 m

PVMBG reported that during 21-28 September foggy weather sometimes prevented visual observations of Sinabung and the growing lava dome in the summit crater. Lava flows on the flanks were incandescent as far as 3 km E to SE. As many as five pyroclastic flows per day were detected, traveling as far as 4 km ESE. Ash plumes rose as high as 4.5 km.


Seismicity consisted of avalanche signals, low-frequency and hybrid events, tremor, tectonic events, and volcanic earthquakes. Seismicity fluctuated at high levels, although it had declined compared to the previous week. The Alert Level remained at 4 (on a scale of 1-4), indicating that people within 7 km of the volcano on the SSE sector, and within 6 km in the ESE sector, should evacuate.


Source: GVP ,  PVMBG.

Photo : Tib Nangin.


Kilauea, Hawai :

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary:
Kilauea Volcano continues to erupt at the Overlook Vent within its summit caldera and at Pu’u ‘O’o in its East Rift Zone, showing no significant changes. Seismicity, deformation, and outgassing continue at low background rates. There is no lava flow threat to nearby communities.


The fringes of this huge new breakout were crazy active, breaking the cooled crust, and swallowing up those floating slabs of rock. I’ve witnessed similar activity, but today’s was extremely dynamic. The slab of floating lava in the lower middle of the frame was swallowed in about 10 seconds!

Summit Observations:
In the last day, the lava lake in the Overlook Vent on Kilauea’s summit varied slightly from 50 meters (165 feet) to its current level of 45 meters (145 feet) below the vent rim. No significant change in tilt was noted and seismicity levels are normal. Summit sulfur dioxide emission rates ranged from 1,500 to 4,300 metric tons per day during the 2-week period ending September 30.

A lava lake boils in the depths of this little collapse pit in the southwest quadrant of Pu’u ‘O’o crater.


Pu’u ‘O’o Observations:
Eruptive activity continues, with no changes visible in Pu’u ‘O’o crater on thermal webcams and no significant tilt or seismicity was recorded. The sulfur dioxide emission rate from all East Rift Zone vents was about 400 metric tons per day when measurements were last possible on September 14, 2015.

June 27th Lava Flow Observations:
The ‘June 27th’ lava flow continues with scattered surface flow activity within 3 to 7 km (1.9 and 4.3 mi) northeast of Pu’u ‘O’o. The lava flow is not currently threatening any communities.


Source : HVO .

Photo : Bruce OMORI.

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