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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
 Fuego - Landsat8 band image 7,6,2 from 05.16.2021 / USGS & Nasa - Doc. Insivumeh

 Fuego - Landsat8 band image 7,6,2 from 05.16.2021 / USGS & Nasa - Doc. Insivumeh

Moderate to strong explosions are reported at the Fuego, at a rate of 10 to 14 per hour, accompanied by ash plumes at 4500-4800 m. asl. dispersing west and southwest for 15 km. Ash falls are observed, among others, in the areas of Moralia, Santa Sofiia, and Panimache.

From the crater, avalanches of boulders move towards the main barrancas.

Due to heavy rains, lahars can also affect these drainages

 

Source: Insivumeh May 16, 2021

Fagradalsfjall eruption - Landsat 8 image -Nasa Earth observ. / 16.05.2021 - In this false color document, blue represents the vent, green the lava pond / river and the yellow-orange active lava flow. Doc. via Ingibjörg Jónsdóttir -University of Iceland - one click to enlarge photos.

Fagradalsfjall eruption - Landsat 8 image -Nasa Earth observ. / 16.05.2021 - In this false color document, blue represents the vent, green the lava pond / river and the yellow-orange active lava flow. Doc. via Ingibjörg Jónsdóttir -University of Iceland - one click to enlarge photos.

On 16.5.2021, the orbit of the LANDSAT-8 USGS satellite and NASA covered the Reykjanes peninsula and a very good image was obtained of the eruption sites at Geldingadalur.

The scanner on board the satellite is sensitive to many wavelengths, allowing users to view various properties of the Earth's surface. Looking in particular at central and near infrared radiation, it is possible to distinguish between craters, lava flows, edges of active lava, and other surfaces. Today's photo clearly shows the intensity of activity in Geldingadalur, the “anonymous” valley and Meradalur.

Fagradalsfjall / Geldingadalur - 05/16/2021 / 9:30 p.m. - webcam_langihryggur N

Fagradalsfjall / Geldingadalur - 05/16/2021 / 9:30 p.m. - webcam_langihryggur N

Fagradalsfjall / Geldingadalur - 05.17.2021 / 6.30am - webcam_langihryggur N

Fagradalsfjall / Geldingadalur - 05.17.2021 / 6.30am - webcam_langihryggur N

There is a new surface break in the northern part of Geldingadalir, which appeared through an inflation gap around 9 a.m. and which initially developed quite rapidly. The inflation gap began to form last night, highlighted by glowing lava, and demonstrates that there is molten lava beneath the solidified lava surface in Geldingadalir. This molten lava core is likely maintained by fountain-fed lava that surges through the SW breach in the crater ramparts during each fountain episode.

An overflow of the lava flow faces south from the main lava river, and has since flowed into the southern part of Geldingadalir. The advance of this lava branch has increased dramatically over the past two days - perhaps in response to the lava dams that have been erected at the southern end of the "Nameless Valley"? The construction of the dam continues.

At around 5:47 p.m. on May 16, a collapse of the inner wall of the active crater could be observed, underlined by a small darker plume.

 

Source: Univ. Iceland

Langila - hot spot from 03.05.2021 (photo center)- image Sentinel-2 bands 12,11,4 - a click to enlarge

Langila - hot spot from 03.05.2021 (photo center)- image Sentinel-2 bands 12,11,4 - a click to enlarge

In Papua New Guinea, VAAC Darwin reported an ash plume at the Langila volcano on May 15 at a flight altitude of 070, or about 2,100 meters (based on Himawari-8 images).

The aviation code is orange.

Frequent light to moderate explosive eruptions with ash emissions and lava flows have been recorded since the 19th century from three active craters at the top of Langila, which is a cluster of four small, overlapping basaltic-andesitic composite cones at the western tip of New Britain.

The thermal satellite images and the MODIS thermal data suggest since 2018 a continuous activity to this day. (GVP: Oct 22, 2015 - continuing to May 6, 2021)

 

Sources: VAAC Darwin and Global Volcanism Program

Piton de La Fournaise - 07.05.2021 / 10:17 - pano zoom webcam - OVPF - one click to enlarge the photos.
Piton de La Fournaise - 07.05.2021 / 10:17 - pano zoom webcam - OVPF - one click to enlarge the photos.

Piton de La Fournaise - 07.05.2021 / 10:17 - pano zoom webcam - OVPF - one click to enlarge the photos.

At Piton de La Fournaise, the amplitude of the volcanic tremor (indicator of an emission of lava on the surface) continues its slow decrease that began on May 2.

The images from the OVPF and OVPF / IRT cameras over the last 24 hours show that:

- the two cones are still active with a strong degassing ;

- the flow of lava at the exit of the eruptive vents, occurs mainly in tunnels up to the upper limit of the large slopes, where resurgences of lava are sometimes visible on the surface;

 - the flow front progresses only very slowly in the Grandes Pentes.

Over the past 24 hours, 2 superficial volcano-tectonic earthquakes (between sea level and the surface) have been recorded, located directly above the summit craters.

The CO2 fluxes in the soil are always increasing in the far field (Plains region). A slight inflation trend in the summit area is again recorded.

Observations made in the field on 11/04 and analyzes of the eruptive products show the presence of the emission of a poorly degassed magma at the start of the eruption. Sampling on 05/03 revealed the arrival at the surface of new, warmer magma, which may correspond to the deep source of magma that pressurized the more shallow magma emitted at the start of the eruption.

 

Source: OVPF 

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