July 31, 2015. English . Piton de la Fournaise, Krakatau, Lokon-Empung , Manam.
July 31, 2015.
Piton de la Fournaise, La Réunion :
Volcanological BULLETIN FOR THE MONTH OF July 2015
Following the eruption of May 2015, except the deformations (see later in the text), the volcano has shown that very few signs of activity throughout June (less of an earthquake under the summit per day and moderate to low flow gas). Since the beginning of July the sensors of OVPF recorded a marked increase in activity. This situation led the prefecture to spend at alert level « imminent eruption » on July 6. The alert level was dropped later but the prefecture has maintained an order prohibiting access to the summit because of the risk of occurrence of an eruption and / or landslides.
431 volcano-tectonic earthquakes summital (VTS) and 581 collapses of rocks in the crater Dolomieu were recorded between the 1st and 29 July representing more than 15 VTS by days with significant variations:
– 92 (VTS) on July 6
– 47 (VTS) on July 13
– 47 (VTS) on July 26
– 67 (VTS) on July 27
– 50 (VTS) on July 28
Cumulatively, the shifts observed since late May show a cone inflation of about 3-4 cm.
This reflects the continuation of a pressurization in depth. The distribution of deformation and the models show a pressure source located around 1-2 km deep under the Dolomieu crater.
Figure 2: Deformation measured over two months by the GNSS network of OVPF
Total emitted of volcanic gases
* Fixed DOAS (NOVAC – Bord de l’Enclos)Flux of SO2 below or near the detection limit (= diffuse emissions, no gas plume supported)
* Multigas (DSO – Piton de la Fournaise top):
The high concentrations of H2S that preceded the seismicity peaks of 06 and 13 July are not detected. Since July 10 is detected fairly low concentrations of H2S and a slight increase in SO2 emissions.
The increase in micro-seismicity observed since July 21 was preceded and associated with an increase in water vapor emissions and CO2 enrichment of gaseous emissions.
* CO2 Flux floor (Rift Zone NO):
– BLEN (Piton Blue) Stable to high values
– PNRN (Plaine des Palmistes): Stable to high values
– PCRN (OVPF): Stable to high values
Source : OVFP.
Photo : aupieddenosvolcans
Krakatau , Indonésie :
6.102 ° S, 105,423 ° E
Summit : 813 m
PVMBG reported that during 1 June-12 July diffuse white plumes were observed rising 25 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity fluctuated at a high level, and continued to be dominated by shallow and deep volcanic earthquakes. Signals indicating emissions were also recorded. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the volcano within 1 km of the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi, GVP.
Photo : Tom Pfeiffer .
Lokon–Empung , Sulawesi , Indonésie:
1.358 ° N, 124,792 ° E
Summit : 1580 m
PVMBG reported that during 15-22 July observers at the Lokon Observation Post in Kakaskasen Tomohon, North Sulawesi (4 km from the crater) reported that, although inclement weather sometimes obscured views of Lokon-Empung’s Tompaluan Crater, white plumes were observed rising as high as 75 m above the crater.
The number of volcanic earthquakes declined but still remained higher than levels recorded during 25 May-10 July. Signals indicating emissions were occasionally detected. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were reminded not to approach Tompaluan Crater within a radius of 2.5 km.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, aussi connu comme CVGHM)
Photo : Antara ( 2011)
Last minute :
Manam, Papouasie-Nouvelle Guinée :
According to Darwin VAAC, a new explosive eruption occurred on Manam, Papua New Guinea, that is passed in red code.
After producing the last weeks small ash plumes reaching 8-10 km, the explosive eruption seen by the Himawari-8 satellite is much larger, similar to the one that hit the volcano in 2004-2005. The first signs are taken by Himawari reported at 1:20 UTC.
Visual reports indicate that a plume is approximately 20 km with ash drifting southwest.
Source : Blog Bernard DUICK : http://www.earth-of-fire.com/2015/07/manam-importante-eruption-explosive-code-rouge.html