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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
Merapi / Java - 23.02.2019 / 6:40 AM WIB - photo Kasan Kurdi

Merapi / Java - 23.02.2019 / 6:40 AM WIB - photo Kasan Kurdi

At Merapi / Java, the PVMBG noted, for February 23, 26 earthquakes collapses, and one breath earthquake.

For 24 February, there are 8 earthquakes of collapses that are mentioned between 0 and 18h. ; two pyroclastic flows were observed flowing over a distance of 200 to 900 meters.

The activity level remains at 2 / waspada, with a prohibited area of ​​3 km.

 

Sources: PVMBG, Magma Indonesia and BPPTKG

Merapi - summary table of activity of 23.02.2019 - Doc.BPPTKG

Merapi - summary table of activity of 23.02.2019 - Doc.BPPTKG

In Peteroa / Chile, surface activity has continued since the beginning of February. The gray plumes, with a maximum height around 2,000 meters above the crater are still observed this 23 February.

The alert level is amarillo / changes in the behavior of volcanic activity in terms of weeks or months.

Source: Sernageomin and CNEA-Segemar

Peteroa - 23.02.2019 / 12h42 - photo CNEA - Segemar

Peteroa - 23.02.2019 / 12h42 - photo CNEA - Segemar

At Piton de La Fournaise, the intensity of the eruptive tremor (indicator of the intensity of the eruption) is relatively constant since February 20 at 06h local time, increasing very slightly this February 23.

Over the past 36 hours, 20 superficial superficial volcano-tectonic earthquakes (above sea level) have been recorded.

After a deflation of the building related to magma transfer that occurred on 18/02/2019, the deformations of the summit zone do not show any particular signals.

The CO2 concentrations in the near field soil (volcano deposit area) remain high.

Over the last 36 hours, surface flows estimated from satellite data, via the HOTVOLC platform (OPGC - University of Auvergne), fluctuated between 2.5 and 15 m³ / s (with a peak at 25 m³ / s) .

Source: OVPF

Find all the information related to the Piton de la Fournaise activity on the different media of the OVPF-IPGP:
- the website (http://www.ipgp.fr/fr/ovpf/actualites-ovpf),
- the Twitter account (https://twitter.com/obsfournaise?lang=en),
- and the facebook account (https://www.facebook.com/ObsVolcanoPitonFournaise/)

Piton de La Fournaise - photo captioned of the activity of February 2019 - Doc. Reunionbysat

Piton de La Fournaise - photo captioned of the activity of February 2019 - Doc. Reunionbysat

Piton de la Fournaise - eruption in the evening of 23.02.2019, seen from the lava road - photo Reunionbysat

Piton de la Fournaise - eruption in the evening of 23.02.2019, seen from the lava road - photo Reunionbysat

A preliminary map released this week by the US Geological Survey shows the thickness of lava flows from the last Kilauea volcano eruption.

The eruption began last May in the areas of Leilani and destroyed more than 700 houses in the lower Puna. It continued vigorously until early August, when the lava flows began to stop. According to the USGS, lava flows from 24 cracks buried an area of ​​about 13.7 square miles and added about 875 acres of new land to the island. These flows vary in thickness.

The greatest thickness on earth, at crack 22, was about 180 feet / 55 meters. And the greatest thickness in the lava delta, or the new earth created at the place where the lava entered the ocean, is about 919 feet / 280 m., off the hot Ahalanui ponds. At crack 8, the most active crack of the eruption, the lava is 167 feet / 51 m. thick.

Janet Babb, geologist and spokeswoman for the USGS Hawaiian Volcano Observatory, said the thickness of the lava delta was a topic of interest. In the past, when lava entered the ocean, there were often delta collapses due to steeper slopes off the coast. But as the topography at sea was not as steep near Kapoho, the delta was built quite far away and, in this case, "we did not have a major collapse of the delta", she said.

A final map will be published once all remote sensing data has been collected and processed, and the current values ​​on the map may change once the data is finalized.

Babb said much of the data was collected by unmanned aerial vehicles and helicopters during last summer's high-tech activities, but some areas were too far away for drones to fly or helicopters could not flying due to lava plumes where lava has entered the water. But now that the eruption is stopped, geologists can get the necessary data from these areas.

In addition, USGS "is still studying the entire flow field and is continuing to refine measurements made this summer", Babb said.

 

Source: West Hawaii Today

Hawaii - Preliminary Map of Lava Thicknesses - Doc. USGS 02.2019

Hawaii - Preliminary Map of Lava Thicknesses - Doc. USGS 02.2019

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