mercredi, janv. 09, 2013
Comme Activolcans.info vient de communiquer, le KVERT a abaissé le niveau d'activité de l'Alaïd au vert. Dans leur dernier rapport les volcanologues russes expliquent ce qu'ils ont observé sur l'édifice depuis octobre 2012. ... [details]
samedi, nov. 10, 2012
A strong thermal anomaly remains visible at Alaid volcano. [details]
Alaid volcanAlaid est le volcan plus haut et les plus au nord dans les îles Kouriles. Le stratovolcan symétrique s'élève à 3000 m de fond de la mer et forme une petite île. Il possède un cratère de 1,5 km de large sommet violé au sud. Il est un des volcans les plus actifs des Kouriles. Grandes éruptions explosives a eu lieu en 1790 et 1981 et ont été parmi les plus importants dans les Kouriles à l'époque historique.
Introduction:Numerous flank cones dot the lower flanks of the basaltic to basaltic-andesite Alaid volcano, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption.
Alaid has 2 types of eruptions: summit activity from the central crater as well as lateral eruptions. The eruptions from the central crater tend to be more explosive and are more dangerous. The largest eruptions from the central crater were in February 1793, June 1854, July 1860, 1894, and April 1981.
The principal volcanic hazard from Alaid are ash plumes dangerous for aircraft (many routes from N-America to Asia pass nearby).
Seismic tremor began at Alaid volcano on 31 October and continued until November. The tremor was believed to be caused by strong winds, not caused by volcanic activity. (Source: GVP monthly roports)
In August 1997, a thermal hotspot was visible on satellite images of the volcano indicating eruptive activity. Ashfall occurred on SW Kamchatka.
Seismic activity increased in December 1996. Satellite images showed a plume reaching a height of 6 km above the volcano. A large snow storm prevented any visual observations. (GVP monthly reports)
1986 collapse of cone in summit crater
Aerial observations on 25 May 1986 revealed that the summit crater's 1981 cone (250 m high and 600 m across at its base) had been almost entirely destroyed recently. At its place there were 2 collapse craters, the larger of which measured 300 m across and ca. 100 m deep.
(Source: GVP monthly reports)
1981 eruption of Alaid volcano
The eruption of Alaid volcano in 1981 ranks as one of the largest in the Kurile Islands in historical times. ...plus
1972 lateral and submarine eruption
A lateral, partly submarine eruption began at Alaid volcano in June 1972. An eruptive fissure extended from the NW base of the volcano to the sea. The water-magma interaction produced powerful explosions and ash plumes 8 km high.
Earlier historic eruptions from Alaid volcano
1933-1934 eruptions: the first observed flank eruption
1894: summit eruption
1860: eruption from the summit crater
1854: strong explosive eruption from the summit crater
1793: explosive eruption from the summit crater
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