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Earth of fire

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

Publié le par Bernard Duyck
Publié dans : #volcanic activity
 Anak Krakatau - 24.06.2019 - comments below - image Sentinel 2 nat. colors - one click to enlarge

Anak Krakatau - 24.06.2019 - comments below - image Sentinel 2 nat. colors - one click to enlarge

An explosive eruptive episode marked Anak Krakatau on June 25 around 9:22 local, filmed by a PVMBG camera installed on the island.

The seismogram imprint lasted 149 seconds.

On the images, we can see a black cypressoid plume followed by the rise of a whiter vapor plume. - video transmitted by Devy Syahbana on Twitter: https://twitter.com/i/status/1143372011177033728

On the Sentinel 2 image of 24.06.2019, there is less water staining than before, a change in the color of the lagoon waters, and a landslide that occurred on Rakata.

The aviation code is orange and the volcanic alert level remains at 2 / waspada.

 

Sources: PVMBG, Devy Kamil Syahbana, & Sentinel 2

Anak Krakatau - seismogram of 24-25.06.2019 - Doc. Magma Indonesia

Anak Krakatau - seismogram of 24-25.06.2019 - Doc. Magma Indonesia

After the eruption of 21 June 2019 at 18:05 UTC at the Raikoke volcano, in the Kuril archipelago, details are given both by the SVERT and the images of NASA.

Six explosions were recorded on June 21 between 18:05 and 18:30 UTC, with a plume of ash and gas rising to 13,000 meters above sea level (and even 17,000 m for some parts of the plume, according to Calipso satellite data)

On June 22, the plume of ash extended over 950 km. in the direction of the east. On the morning of June 22, the ISS astronauts photographed the volcanic plume forming a narrow column and then extending partly into the "umbrella" zone. This is the area where the density of plume and ambient air are balanced and where the plume ceases to grow. The cloud ring at the base of the column appears to be water vapor.

Raikoke - the eruptive plume of 22.06.2019 of the ISS059e119250 / Doc. Nasa Earth Observatory

Raikoke - the eruptive plume of 22.06.2019 of the ISS059e119250 / Doc. Nasa Earth Observatory

Raikoke - the ash plume by Sentinel-2 nat. colors of 23.06.2019

Raikoke - the ash plume by Sentinel-2 nat. colors of 23.06.2019

In addition to monitoring the ashes, satellite sensors can also track volcanic gas movements. In this case, Raikoke produced a concentrated sulfur dioxide (SO2) plume that separated from the ashes and swirled throughout the North Pacific when the plume interacted with the storm.

 Raikoke - the cloud of sulfur dioxide, separated from the ash cloud, has swirled over the North Pacific - Sentinel 5P / Tropomi image from 23.06.2019 / 00h22- 02h07 UT, via Simon Carn

 Raikoke - the cloud of sulfur dioxide, separated from the ash cloud, has swirled over the North Pacific - Sentinel 5P / Tropomi image from 23.06.2019 / 00h22- 02h07 UT, via Simon Carn

On June 23, the ship Athena, making a tourist trip to the Kuril Islands, approached the island. Thanks to expedition member Nikolai Pavlov, the first photographs of the Raikoke volcano after the eruption began and its first description were obtained.

" On June 23 at 17:20, Kamchatka time, we approached the west side of Raikkok, the entire surface of the island was covered with a thick layer of whitish-beige ash that could reach several tens of centimeters per square meter, fresh scree was several meters thick, the water is highly mineralized, with a characteristic yellowish-greenish tint, closer to the brown shore, and lava flows have not been observed. When the waves rolled in some places, steam explosions occurred with the release of dark brown steam, and the plume of ash and gas from the crater was heading west at a height of about 1.5 km. above the crater.
The photographs show that the coastline is considerably altered by pyroclastic flow deposits. There are many secondary fumarolic streams on the sediment surface.
"

 

Sources: KSCNET, SVERT, S.Carn and Nasa Earth Observatory.

Raikoke - the eruption seen by N.Pavlov on 23. 06.2019 - photo N.Pavlov / East tower via KSCNET

Raikoke - the eruption seen by N.Pavlov on 23. 06.2019 - photo N.Pavlov / East tower via KSCNET

Raikoke - the shore covered with deposits of pyroclastic flows - photo 23.06.2019 N.Pavlov / East tower via KSCNET

Raikoke - the shore covered with deposits of pyroclastic flows - photo 23.06.2019 N.Pavlov / East tower via KSCNET

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