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Earth of fire

Actualité volcanique, Article de fond sur étude de volcan, tectonique, récits et photos de voyage

Publié le par Bernard Duyck
Publié dans : #Excursions et voyages

An overview of several little known Ecuadorian volcanoes was made on 28 January by the teams of the IGEPN, with the logistical support of the Cessna-206 of ADS / Alas de Socorro del Ecuador. It allows us to speak of the Imbabura and Sumaco volcanoes.
 

 Ecuador - The Avenida de los Volcanes - location of Sumaco and Imbabura volcanoes.

Ecuador - The Avenida de los Volcanes - location of Sumaco and Imbabura volcanoes.

 The northwest flank of Sumaco, towering 2,800 meters over the surrounding jungle - photo P. Ramón / IGEPN / 01.28.2016.

The northwest flank of Sumaco, towering 2,800 meters over the surrounding jungle - photo P. Ramón / IGEPN / 01.28.2016.

The stratovolcano Sumaco - 0.538 ° S / 77 626 ° W - is located in an area of ​​uninhabited jungle and difficult to reach, due to dense vegetation and an often muddy field ... a 4 day hike to get there requires an excellent physical condition and nerves of steel, especially if the rain starts the game.

The volcano, which rises to 3,990 meters, forms a relatively symmetrical cone in this region dominated by heavy rains and erosion. The summit crater, wide 300 to 400 meters, contains a central cone.

 

The Sumaco - photo Andreas Kay 2015 / Flickr - Attribution-NonCommercial-ShareAlike 2.0 Generic

The Sumaco - photo Andreas Kay 2015 / Flickr - Attribution-NonCommercial-ShareAlike 2.0 Generic

It is isolated and eccentric eastward relative to the Andean volcanic axis. Built on a foundation of sedimentary rocks of the Cretaceous, it produced rocks whose composition differs from that of the volcanic chain : phonolite, basanite, téphrite.

His last activity dates back to 1895 ± 30 years, based on historical observations.
Its flyby in January showed no surface activity, and thermal images show no abnormality.

It is isolated and eccentric eastward relative to the Andean volcanic axis. Built on a foundation of sedimentary rocks of the Cretaceous, it produced rocks whose composition differs from that of the volcanic chain: phonolite, basanite, téphrite.  His last activity dates back to 1895 ± 30 years, based on historical observations.  Its flyby in January showed no surface activity, and thermal images show no abnormality. From left to right, the city of San Pablo del Lago, on the shores of Laguna de San Pablo and the Imbabura and huarmi the summit, Taita Imbabura - photo Patricio Ramon / IGEPN

It is isolated and eccentric eastward relative to the Andean volcanic axis. Built on a foundation of sedimentary rocks of the Cretaceous, it produced rocks whose composition differs from that of the volcanic chain: phonolite, basanite, téphrite. His last activity dates back to 1895 ± 30 years, based on historical observations. Its flyby in January showed no surface activity, and thermal images show no abnormality. From left to right, the city of San Pablo del Lago, on the shores of Laguna de San Pablo and the Imbabura and huarmi the summit, Taita Imbabura - photo Patricio Ramon / IGEPN

Further north of Quito, near the town of Otavalo, Imbabura volcano - 0.258 ° N / 78183 ° W - dominates the Laguna San Pablo, in the inter-Andean valley.

It consists of a main building, the Taita Imbabura
"Father Imbabura" - who shaped the summit, and on its southwestern flank, a side lava domes complex, the Huarmi Imbabura - "Imbabura's Son"
.

The southeast flank of the Imbabura - we can see the cultures that go back on the slopes of the volcano - photo P. Ramón / IGEPN / 01.28.2016.

The southeast flank of the Imbabura - we can see the cultures that go back on the slopes of the volcano - photo P. Ramón / IGEPN / 01.28.2016.

The activity of the Imbabura in Pleistocene built a large andesitic stratovolcano; she stopped 43,000 years ago with a major collapse, which produced a debris avalanche that traveled 16 km to the north.

Growth of the Imbabura II then continued at least until the beginning of the Holocene and has been made of growing and collapse phases of a large complex of domes of dacitic lava. A major eruption produced an avalanche of debris and a possible lateral blast, 25,000 years ago.

The activity then produced the growth of the Huarmi Imbabura lava dome.

Historical records mention only rockslides and mudslides.
Its flyby in January showed no surface activity, and thermal images show no abnormality.

 

Sources :

- IGEPN - Resumen de las observaciones efectuadas durante el vuelo efectuado el 28 de enero de 2016

- Global Volcanism Program - Sumaco

- Global volcanism Program - Imbabura

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