24/04/2015 : Calbuco, Raung .
Calbuco, Chili :
The violent eruption of the volcano that had started at 01:00 local time this morning lasted about 6 hours and gradually waned. However, a third explosion in the near future remains a possibility.
A 20 km access exclusion zone around the volcano remains in place and the alert status is kept at maximum (red).
During the most intense phase, an impressive lava fountain could be seen jetting from the vent and the eruption column rose to more than 15 km altitude. An ash plume quickly drifted north, northeast and east into Argentina. Ballistic incandescent bombs were ejected to distances of up to 5 km.
Strong seismic activity with a medium of 150 volcanic-tectonic earthquakes of magnitudes up to 3.6 were recorded during the paroxysmal phase of the eruption.
Significant ash fall of up to 50-60 cm occurred in nearby downwind areas, while in the more distant areas of Los Ríos and Araucaní some millimeters of ash fell.
More than 4100 people were evacuated after the first eruption yesterday evening. A curfew was in place in Puerto Montt, Puerto Varas and Puerto Octay from 23:45 to 05am to prevent looting in abandoned houses and shops.
Although the eruption was extremely violent, produced abundant heavy ash fall and pyroclastic flows, it seems that it only claimed one victim. A young mountaineer who at the time of the eruption was at a mountain shelter was reported missing.
Satellite images show interesting gravity waves (ripple-shaped ring waves) in the ash plume that developed when the initial plume rose into the stratosphere and spread laterally.
There were two eruptive pulses, pyroclastic flows, lava flows and ash columns.
The falls of lapilli and ash reached more than 50 to 60 cm. in areas close downwind as in Ensenada (15 km from the volcano.), causing major disruptions to traffic and some roof collapses (40 cm ash by weight are around 600- 800 kg / m²); in the distal regions of Los Rios and Araucani, the layer of ash was millimeter order.
The National Geology and Mining Service (SERNAGEOMIN) by the National Volcanic Monitoring Network, has published several special reports (REAV) on the activity of the volcano Calbuco, ranked No. 3 on Hazard scale of 90 active volcanoes in Chile which is on red alert after the process of eruption that began April 22 at 18:05 hours. According to reports generated by the Andean volcano observatory del Sur (OVDAS), based on the analysis of information obtained from monitoring stations around the area, it was determined that the seismicity has introduced changes in the behavior of the volcano, first with a swarm of type events VT (activity associated with the breaking of rock, caused by magma flows).In this regard, the national director of SERNAGEOMIN Rodrigo Álvarez Seguel, said “hundreds of earthquakes have been recorded over the two pulses initiated 18 hours on 22 and 1 am on April 23. The second pulse had more energy. on the basis of the foregoing, the restriction zone 20 km around the crater “is maintained”.
The 21 y-o mountaineer who was missing and feared victim of the eruption has survived and has been rescued, fortunately. Together with a small group of friends, he was on excursion on the mountain when the eruption occurred last night.
During their escape, he decided to stay behind because of cramps and then lost his way, forced to spend the night in the forest, until he could make phone contact with his family this morning.
Source : Volcanodiscovery , Sernageomin , blog B Duick .
Photos : FB, dondatos RT / Twitter , Marcelo Utreras , Alexoffroad01
Raung, Indonésie :
8,125 ° S, 114,042 ° E
Elevation 3332 m
PVMBG reported that, during infrequent times of clear weather in December 2014 and January 2015, white plumes were observed rising as high as 500 m above Raung’s crater rim. In February and during 1-14 March plumes were gray-white and rose to a maximum height of 200 m. Crater incandescence and rumbling was reported. During 15 March-7 April emissions were gray-brown and rose as high as 200 m; rumbling continued to be heard.
During 8-15 April gray-brown plumes rose as high as 300 m. Rumbling was heard on 8 April and crater incandescence was observed on 12 April. Continuous tremor was recorded during December 2014-12 January 2015; tremor was not continuous starting on 13 January, and RSAM values declined. The Alert Level remained at 2 (on a scale of 1-4
Source: GVP , Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, aussi connu comme CVGHM)
Photo : B Fourie