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

Activity of Fuego, Karangetang and Etna - Dating of the Deception island caldera.

Fuego - 26.11.2018 - photo Edilverto Santos via Clima Guatemala

Fuego - 26.11.2018 - photo Edilverto Santos via Clima Guatemala

The Fuego maintains moderate to strong explosions at a rate of 12 to 15 per hour, a vulcanian-type activity according to Insivumeh.

It is accompanied by eruptive columns laden with ashes rising to 5,000 meters asl. and shock waves and vibrations felt within a radius of 25 km.

A change of wind direction, November 26 in the morning from south to north, brings the ashes to Alotenango, San Miguel, Dueñas, Antigua Guatemala and Ciudad Guatemala, the capital.

2018.11.26 10:45 Fuego - Doc.Insivumeh


Sources: Insivumeh & Conred.

Fuego - 26.11.2018 - photo Jiuwit Rosas via William Chigna / Twitter

Fuego - 26.11.2018 - photo Jiuwit Rosas via William Chigna / Twitter

At Karangetang, located north of Siau Island, itself north of Sulawesi, moderate thermal anomalies have been reported since 24 November.

The VAAC Darwin issued an ash dispersion advisory on November 25, and Magma Indonesia reported a small eruption on November 25 and 26, 2018. The height of the emitted ash plume could not be observed due to cloud cover, and has been estimated at 2.284 meters asl .

The activity level is set at 2 / waspada, associated with a danger zone of 1.5 km around the crater, extended to 2.5 km SE, S, SW and O, and an orange VONA.

 

Sources: Magma Indonesia.

Karangetang - thermal anomalies on 27.11.2018 / Mirova and seismicity on 26.11.2018 / Magma Indonesia - one click to enlargeKarangetang - thermal anomalies on 27.11.2018 / Mirova and seismicity on 26.11.2018 / Magma Indonesia - one click to enlarge

Karangetang - thermal anomalies on 27.11.2018 / Mirova and seismicity on 26.11.2018 / Magma Indonesia - one click to enlarge

Karangetang - 25.11.2018 / 7:52 AM WITA - photo Magma Indonesia

Karangetang - 25.11.2018 / 7:52 AM WITA - photo Magma Indonesia

Karangetang - 26.11.2018 / 7.30am WITA - photo Magma Indonesia

Karangetang - 26.11.2018 / 7.30am WITA - photo Magma Indonesia

At Etna, a lava flow, emitted by the "Puttusiddu" vent on the east flank of the new south-east crater, came out of the pit crater on November 26th. His diet continues on November 27 in the morning.

Sources: Boris Behncke and Benito Morabito.

Etna - 26.11.2018 after midnight - On the left, the flow of the puttusiddu / NSEC and on the right, the incandescence at the level of the Bocca Nuova - picture Boris Behncke

Etna - 26.11.2018 after midnight - On the left, the flow of the puttusiddu / NSEC and on the right, the incandescence at the level of the Bocca Nuova - picture Boris Behncke

On Deception island, in the South Antarctic Shetland Islands, the eruption that formed the huge central caldera, with a current diameter of 8-10 km, has only been accurately dated, based on analysis. lacustrine and marine sediments, and ice cores.

The study reveals conclusive and multidisciplinary evidence of a major volcanic episode, with far-reaching effects, 3,980 years ago, accompanied by a volcano-climatic impact on a hemisphere.

Source:The timing and widespread effects of the vast Holocene volcanic eruption in Antarctica - by Dermot Antoniades & al - Scientific Reports volume 8, Article number: 17279 (2018)

Above :Location map showing (A) Deception Island, Byers Peninsula and the Antarctic Peninsula; and (B) sites across Antarctica where the Deception Island caldera collapse event is recorded by tephra and/or rapid post-seismic sediment deposition in ice, lake and marine sediment cores.   Under : (A) Map of Deception Island showing the general geology and outcrop locations of the Outer Coast Tuff Formation (OCTF) (modified from ref.10)  (B) Image of the Vapour Col succession illustrating the contact between the OCTF and post-caldera deposits; (C) Detail of OCTF deposits on Deception Island; (D) detail of Tephra T3 from Byers Peninsula (Lake Limnopolar, core LIM08_F2B), with alternating organic and mineral sedimentation below T3 and rapid, massive sediment above; note the coarseness of the tephra Doc. The timing and widespread effects of the largest Holocene volcanic eruption in Antarctica
Above :Location map showing (A) Deception Island, Byers Peninsula and the Antarctic Peninsula; and (B) sites across Antarctica where the Deception Island caldera collapse event is recorded by tephra and/or rapid post-seismic sediment deposition in ice, lake and marine sediment cores.   Under : (A) Map of Deception Island showing the general geology and outcrop locations of the Outer Coast Tuff Formation (OCTF) (modified from ref.10)  (B) Image of the Vapour Col succession illustrating the contact between the OCTF and post-caldera deposits; (C) Detail of OCTF deposits on Deception Island; (D) detail of Tephra T3 from Byers Peninsula (Lake Limnopolar, core LIM08_F2B), with alternating organic and mineral sedimentation below T3 and rapid, massive sediment above; note the coarseness of the tephra Doc. The timing and widespread effects of the largest Holocene volcanic eruption in Antarctica

Above :Location map showing (A) Deception Island, Byers Peninsula and the Antarctic Peninsula; and (B) sites across Antarctica where the Deception Island caldera collapse event is recorded by tephra and/or rapid post-seismic sediment deposition in ice, lake and marine sediment cores. Under : (A) Map of Deception Island showing the general geology and outcrop locations of the Outer Coast Tuff Formation (OCTF) (modified from ref.10) (B) Image of the Vapour Col succession illustrating the contact between the OCTF and post-caldera deposits; (C) Detail of OCTF deposits on Deception Island; (D) detail of Tephra T3 from Byers Peninsula (Lake Limnopolar, core LIM08_F2B), with alternating organic and mineral sedimentation below T3 and rapid, massive sediment above; note the coarseness of the tephra Doc. The timing and widespread effects of the largest Holocene volcanic eruption in Antarctica

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