Get our newsletter!
Voyages aux volcans actifs !
Volcanoes & Earthquakes - new app for Android
Volcanoes & Earthquakes - app for iPhone & iPad

Départs garantis:
30 mars - 6 avril 2019: Land of Theseus - Saronic Gulf (Greece)
2-17 mai 2019: Du Krakatau à Bali - Java (Indonésie)
4-11(12) mai 2019: Fascinant Volcan et la Légende de l'Atlantide - Île de Santorin, Grèce
4-12 mai 2019: Montagnes de Feu - du Stromboli à l'Etna - Eoliennes + Etna
18-26 mai 2019: Montagnes de Feu - du Stromboli à l'Etna - Eoliennes + Etna
25 mai - 1 juin 2019: Etna Discovery - Etna volcano (Italy)
7-12 juin 2019: Expédition au Volcan Yasur - Vanuatu (Mer du Sud)
15-30 juin 2019: Du Krakatau à Bali - Java (Indonésie)
8-23 juil. 2019: Du Krakatau à Bali - Java (Indonésie)
3-18 sept. 2019: Du Krakatau à Bali - Java (Indonésie)
: Places libres / : Départ garanti / : Quelques places disponibles / : Groupe fermé
Diaporama
Great Sitkin volcan
Stratovolcano 1740+ m / 5,709 ft
United States, Aleutian Islands, 52.08°N / -176.13°W
Condition actuelle: normal / en sommeil (1 sur 5)| Reports
Great Sitkin livres
Eruptions du volcan Great Sitkin:
1974 
Style éruptif tipique:
unspecified
Derniers séismes proches
Derniers images satellite
 

Great Sitkin volcano news & activity updates:

Great Sitkin volcano (United States, Aleutian Islands) activity update

mardi nov. 28, 2017 12:05 | AUTEUR : T

Worldview-3 satellite image of the summit area of Great Sitkin volcano, November 21, 2017. The area of steaming indicated by the red arrow is the likely source of the volcanic emissions noted and photographed by local observers on Adak, November 19, 2017. The melt depressions on the east side of the 1974 lava flow were evident in a September 14, 2017 satellite image but not present in an April 18, 2017 image indicating that they likely formed during the spring-summer 2017. (image: Chris Waythomas / AVO / USGS)
Worldview-3 satellite image of the summit area of Great Sitkin volcano, November 21, 2017. The area of steaming indicated by the red arrow is the likely source of the volcanic emissions noted and photographed by local observers on Adak, November 19, 2017. The melt depressions on the east side of the 1974 lava flow were evident in a September 14, 2017 satellite image but not present in an April 18, 2017 image indicating that they likely formed during the spring-summer 2017. (image: Chris Waythomas / AVO / USGS)
Steaming from Great Sitkin Volcano as visible from the town of Adak (40 km or 25 miles to the SW) (image: Alain Beauparlant via AVO / USGS)
Steaming from Great Sitkin Volcano as visible from the town of Adak (40 km or 25 miles to the SW) (image: Alain Beauparlant via AVO / USGS)
Recent observations of a robust steam plume and a period of gradually increasing seismicity over several months at Great Sitkin prompted AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory on 22 November.
On 19 November local observers photographed a light-colored vapor plume rising about 300 m above the vent and drifting 15-20 km S.
A satellite image acquired on 21 November showed steam continuously jetting from a small fumarole on the W side of the 1974 lava flow within the summit crater, and at least one area where snow and ice had been melted.

Seismicity had fluctuated but increased overall since July 2016, most notably in June 2017. The seismic activity was characterized by earthquakes less than M 1, and occurred either just below the summit or just offshore the NW cost of the island, 30 km below sea level.
Possible explosion signals were recorded in seismic data on 10 January and 21 July 2017, but there were no confirmed emissions.

Source: Smithsonian / USGS Weekly Volcanic Activity Report 22-28 November 2017
Actualités précédentes
vendredi, nov. 24, 2017
An increase in seismic activity and degassing prompted the Alaska Volcano Observatory (AVO) to raise the alert level of the volcano to yellow today: ... [details]
samedi, juil. 22, 2017
An increase in seismic activity was detected at Great Sitkin starting with seismic tremor on July 21 16:17 AKDT (July 22 00:17 UTC). After about an hour, tremor transitioned to discrete earthquakes. ... [details]
 

Plus sur VolcanoDiscovery:

Copyright: VolcanoDiscovery ou autres sources indiquées.
Utilisation des documents: Les textes, les images et les vidéos de ce site internet sont protégées par copyright. Toute reproduction et tout usage sans accord préalable ne sont pas autorisés. Si vous désirez acquérir pour certains documents (photos, vidéos, textes ou autres) le droit de reproduction, d'édition et, plus généralement, de toute utilisation destinée à un usage public, qu'elle soit commerciale ou pas, vous êtes priés de nous contacter.