Toutes les actualités et mises à jour sur les volcans:
Soufrière Hills volcano's dome growth continues, now focused towards the east, with a lava lobe growing in that direction and the majority of rockfall and pyroclastic flow activity occurring in the SE to NE sector. The largest pyroclastic flows during the past week have travelled up to 2km down Tar River valley.
Meakandake volcano in Hokkaido, Japan, erupted shortly on Tuesday afternoon, March 21, 2006. The volcano spewed a small amount of ash and caused a short lahar travelling through a ravine on the upper slopes of the snow-capped volcano.
After the 17 March eruption at Green Lake on Raoul Island, no new eruptions occurred and seismicity declined through 24 March. New Zealand scientists found that many new craters had formed in and around Green Lake and that pre-existing 1964 craters had eactivated. The main steam columns were derived from Crater I, Marker Bay, and Crater XI. The eruption blew over mature trees as far as 200 m from the eruption site and deposited dark gray hydrothermal mud and ballistic blocks....plus
Pacaya volcano is in mild strombolian activity, with lava flows extending ~100-150 m down the volcano's S and SW flank.
Fuego volcano continues its weak strombolian activity, ejecting incandescent material ~50-75 m high and producing gas plumes to ~300 m above the volcano (13,300 ft a.s.l.). Short pyroclastic avalanches occur on the upper flanks. On 28 March, lava flowed ~450 m S and avalanches occurred from the lava-flow fronts. ->More on Fuego
Colima continues its mild activity with occasional ash emissions (a few per day); the highest plume during the past week reached 6.1 km (20,000 ft) a.s.l. on the 26th of March 2006.
Small phreatic eruptions began at Poás on 24 March 2006. The eruptions originated from the bottom of the volcano's Caliente Lake. Witnesses described a sudden emission of water and sediments S of the lake. Roaring was heard in a nearby tourist area and weak earthquakes were felt.
OVSICORI-UNA visited the E side of the volcano on 25 March and confirmed that water, blocks, and sediments from the bottom of the lake had been ejected.Several dozens of impact craters were seen with diameters between 15 and 60 cm, extending E as far as 700 m. Blocks were found that ranged in diameter from a few to 50 cm wide. During 22-27 March, harmonic tremor was recorded. On the 27th, there was a reduction in seismicity and it returned to normal levels. No deformation was measured at the volcano. A news article reported that the area around the volcano was closed to visitors.
Galeras has been showing an increase in tremor since the morning of 28 March, as INGEOMINAS reports. The Alert Level was raised from 3 ("changes in the behavior of volcanic activity have been noted") to 2 ("likely eruption in days or weeks"). In addition to the tremor, seismic instruments detected very shallow low-energy hybrid signals, similar to ones recorded during 1991-1993 when dome emplacement occurred on the main crater's floor....plus
Poás volcano erupted after 12 years of dormancy with two small steam and ash eruptions on 25th of March 2006 from the crater lake known as Laguna Calients. Authorities consider closing the easy-to-access crater rim to the public.
The dome growth of Soufrière Hills volcano is now focused in the summit area and towards the east and northeast. The northern side of the lava dome has shown little change during the past week, as MVo reports. Rockfalls and pyroclastic flows have been restricted to the Tar River Valley and they were particularly numerous on 19-20 March. The largest pyroclastic flows have travelled up to 2km down Tar River valley....plus [lire toutes]