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Earth of fire

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

volcanic activity

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologie, #Eruptions historiques
 The eruptive site of Whakaari / White Island during the surveillance flight of 14.12.2019 - photo GeoNet / Police NZ - one click to enlarge

The eruptive site of Whakaari / White Island during the surveillance flight of 14.12.2019 - photo GeoNet / Police NZ - one click to enlarge

An experienced volcanologist was able to observe the active vent area of ​​Whakaari / White island during the New Zealand police recovery operation.

The above photo was taken by this volcanologist during the surveillance flight, at a safe distance. We can see at least one active vent with a strong degassing (surrounded), the gas temperatures are high (at least 200 ° C), and the blue tint indicates that the plumes are dominated by sulfur dioxide, which comes directly from the shallow magma. This suggests an open-vent volcanic system with magma not too far below the surface, perhaps only a few dozen meters below it.

The other characteristic that stands out very clearly is the old basin of the crater lake, a depression formed by eruptions between 1978 and 1990. Before the Monday eruption, this basin was partially filled by a hot and acidic lake which was at about 16 meters below the overflow point. Now a large part of the basin is filled with debris with many isolated ponds. Much of the accumulated water comes from recent rains which have reacted with eruption deposits.

 Whakaari / White Island - RSAM to 15.12.2019 - Doc. GeoNet - one click to enlarge
 Whakaari / White Island - RSAM to 15.12.2019 - Doc. GeoNet - one click to enlarge

 Whakaari / White Island - RSAM to 15.12.2019 - Doc. GeoNet - one click to enlarge

Since the evening of December 13, a low glow is observable by special cameras to detect the weak night lights, which testifies to the high temperature of the gases.

This December 15, a white plume of gas and steam overcomes the volcano; moving away towards the east of the bay of Plenty and while cooling, it becomes more gray-brown, the particles of gas being highlighted in sunlight.

The Seismicity graphs and the RSAM show a real drop in activity. (Explanatory notions in English on the RSAM and the SSAM on: https://www.geonet.org.nz/about/volcano/rsamssam).

The alert level remains at 2.

 Whakaari / White Island - The volcano and its plume of gas and vapor on 15.12.2019 - photo GeoNet

 Whakaari / White Island - The volcano and its plume of gas and vapor on 15.12.2019 - photo GeoNet

Concerning the assessment of the phreatic eruption, it has been revised upwards unfortunately: 18 dead, and 20 hospitalized in critical condition.

You have to realize that when entering White Island, you are not only on a potentially dangerous volcano, but also in its crater !

It has never worn its Maori name so well: "Te Puia o Whakaari - The dramatic volcano".

 

Source: GeoNet - answers to questions by Brad Scott / 15.12.2019 / 7 p.m. local.

State of White Island, earthquakes in the Reykjanes peninsula and a look back at the 1989 Redoubt eruption.
State of White Island, earthquakes in the Reykjanes peninsula and a look back at the 1989 Redoubt eruption.
State of White Island, earthquakes in the Reykjanes peninsula and a look back at the 1989 Redoubt eruption.

A seismic swarm is underway at Fagradalsfjall in the Reykjanes peninsula. It started on December 15 with an earthquake of M3.5, and two earthquakes of M3.6 at 7:57 p.m; More than 900 earthquakes have been detected in this swarm, including a dozen magnitudes around M3, felt in Grindavik, Keflavik, Reykjavik and Akranes.

In July 2017, a similar seismic swarm occurred in the same area.

Earthquakes are common in this region with many faults.

 

Mount Fagradalsfjall, the westernmost part of the mountain ridge of the Reykjanes peninsula, is actually a small plateau. Some hyaloclastite ridges protrude, especially in the western part. Its highest altitude is 385 m. above sea level.

Source: IMO

Reykjanes Peninsula - volcanic systems and faults

Reykjanes Peninsula - volcanic systems and faults

Mt.Fagradalsfjall - photo The Dabbler

Mt.Fagradalsfjall - photo The Dabbler

Little back on the eruption of the Redoubt volcano, located in the Cook Inlet in Alaska in December 1989.

Redoubt - 16.12.2019 / 12h -photo Andy Hutchinson - AVO

Redoubt - 16.12.2019 / 12h -photo Andy Hutchinson - AVO

 Front page of the Anchorage Daily Mail of 16.12.1989 - Doc AVO - one click to enlarge 

 Front page of the Anchorage Daily Mail of 16.12.1989 - Doc AVO - one click to enlarge 

In addition to disrupting oil production and storage facilities for almost a year, it wreaked havoc on domestic and international air traffic: on December 15, 1989, a Boeing 747 in flight from Amsterdam, which flew into the ash cloud several hours after the eruption, suffered a complete engine failure and narrowly avoided a tragedy when the crew successfully restarted the engines and enabled a safe landing at Anchorage. Two other aircraft were damaged by ash on the same day, with no engine failure, however.

 Redoubt - eruption in progress on 18.12.1989 / 12h -photo W.M.White / AVO

 Redoubt - eruption in progress on 18.12.1989 / 12h -photo W.M.White / AVO

Following these incidents, the eruption of Redoubt marked the start of systematic monitoring by the Alaska Volcanological Observatory of the 54 historically active volcanoes of Alaska and the Aleutians, and an awareness of the dangers of emissions of volcanic ash.

 

Sources:

- AVO / Redoubt 1989/12 - link

- Global Volcanism Program, 1989. Report on Redoubt (United States). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 14:12. Smithsonian Institution - link

FrontierScientists.com - Game McGimsey of the USGS Alaska Volcano Observatory tells the story of a KLM 747 jet losing all 4 engines after flying through an ash cloud produced by Mt. Redoubt.

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Underwater volcnism

Since August 2019, a large accumulation of pumice has drifted in the Southwest Pacific to Australia.

Researchers at the GEOMAR Helmholtz Center for Ocean Research Kiel and colleagues from Canada and Australia, have now identified the origin of the pumice raft. It is a hitherto unnamed underwater volcano in the waters of the Tonga Archipelago.

Various underwater volcanoes were discussed at the time as a potential source. But direct proof of the exact origin of the pumice stone has so far been lacking.

 Tonga Archipelago - pumice raft - Sentinel 2 image 11.08.2019 via S.Carn

 Tonga Archipelago - pumice raft - Sentinel 2 image 11.08.2019 via S.Carn

Pumice from the underwater eruption in the Pacific - photo Sail Surf ROAM by Liss / 20.08.2019

Pumice from the underwater eruption in the Pacific - photo Sail Surf ROAM by Liss / 20.08.2019

It concerns an underwater volcano just 50 kilometers northwest of the island of Vava'u in the Tonga archipelago. In the international scientific literature, it appears so far only under the number 243091 or under the name of Volcano "F", explains Dr. Philipp Brandl of GEOMAR, first author of the study.

"The team found what they were looking for on freely accessible satellite images. On an image of the ESA Copernicus Sentinel-2 satellite taken on August 6, 2019, clear traces of an active underwater eruption may be Since the images are exactly georeferenced, they could be compared to the corresponding bathymetric maps of the seabed ", collected in January by the Archimedes expedition / research vessel Sonne. "The eruption traces correspond exactly to volcano F", says Dr. Brandl.

To be sure, the researchers also compared this position with information from stations in the global seismic network that recorded the eruption signals. Despite their low number in this region, their data are consistent with the "F" volcano as its origin.

Volcano "F" from old bathymetric data - Graphic Philipp Brandl -GEOMAR

Volcano "F" from old bathymetric data - Graphic Philipp Brandl -GEOMAR

Pumice can form during volcanic eruptions when viscous lava is "turned into foam" by volcanic gases such as water vapor and carbon dioxide. This creates so many pores in the cooling rock that its density is less than that of water. "During an underwater eruption, the probability of generating pumice is particularly high", says Dr. Brandl.

Path and positions of the pumice raft, reconstructed in the study, between August 8 and August 14, 2019 - Graphic Philipp Brandl

Path and positions of the pumice raft, reconstructed in the study, between August 8 and August 14, 2019 - Graphic Philipp Brandl

Tonga volcano F - pumice samples - Schmidt ocean institute / 11.12.2019

Tonga volcano F - pumice samples - Schmidt ocean institute / 11.12.2019

Using additional satellite images, the team traced the drift and dispersion of pumice raft until mid-August (map above). It slowly drifted west and reached an area of ​​up to 167 square kilometers. The team was also able to determine the extent of the underwater eruption. It would correspond to a volcanic eruption index of 2 or 3.

With the current direction and speed, pumice raft should touch the Great Barrier Reef off the east coast of Australia in late January or early February. Biologists, in particular, are eagerly awaiting this event as pumice rafts can play an important role in the dispersal of wildlife in the vastness of the Pacific Ocean. The Kiel team of geologists would like to examine pumice samples to more precisely determine the geochemistry of volcano F.

 

Sources:

 - Geomar - Vulkan „F“ ist der Ursprung der schwimmenden Steine ​​- Forscher veröffentlichen Studie zum Bimssteinfloß im Südwestpazifik - link

- The study was published online in the international journal Journal of Volcanology and Geothermal Research: The 6–8 Aug 2019 eruption of ‘Volcano F’ in the Tofua Arc, Tonga - Philipp A.Brandt & al. - link

- Schmidt Ocean Institute - Traces of an underwater volcano - 11.12.2019 - link

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Bezymianny - photo archive KVERT 20.03.2019

Bezymianny - photo archive KVERT 20.03.2019

The aviation code of Bezymianny, in Kamchatka, was raised to orange this December 13 at 11:40 am.

The activity of the volcano started to increase in December, characterized by glow at the summit in dark time, a lava flow and sometimes a strong fumarolic activity.

Thermal anomalies punctuate the increasing activity.

 

Bezymianny - thermal anomalies on 14.12.2019 - Doc. Mirova


For the moment, no ash cloud is reported, but ash explosions can occur at any time, reaching 10-15 km asl.

 

Sources: KVERT & Mirova

Shishaldin - image 12.12.2019 / 22:31 UTC - Dietterich, Hannah via AVO

Shishaldin - image 12.12.2019 / 22:31 UTC - Dietterich, Hannah via AVO

In Shishaldin, eruptive activity intensified on December 13, with a possible collapse of the spatter cone and lava flows on the north and northwest flanks. The episode was accompanied by an ash cloud at 7,600 meters asl.

Surface temperatures are observed by satellite.

A plume of steam is visible at the top, as well as night glow.

On a photo from December 12, we can see pephra stretching over ten kilometers to the southeast; the pyroclastic flow deposits extend on the north side for 3.5 km, with metric blocks, and lahars extend in the northwest to the north coast of Unimak.

 

Source: AVO

Japan / Kyushu - plumes of sakurajima (bottom) and Asosan (1/3 upper) - Sentinel-2 bands image 12,11,4 dated 13.12.2019

Japan / Kyushu - plumes of sakurajima (bottom) and Asosan (1/3 upper) - Sentinel-2 bands image 12,11,4 dated 13.12.2019

In Japan, the two active volcanoes on Kyushu, the Sakurajima and the Aso continue their emissions, visible on the Sentinel-2 image of December 13.

The JMA reports for Asosan two eruptive episodes on December 14 and 15, the last at 9 am local time.

At Sakurajima, 2 to 3 daily explosions have been reported since December 9.

 

Sources: JMA and VAAC Tokyo

Sakurajima - 13.12.2019 / 9.45 am - webcam and ash dispersion viaJMA

Sakurajima - 13.12.2019 / 9.45 am - webcam and ash dispersion viaJMA

Seismic activity remains appreciably weak this week at the Poás volcano with essentially volcanic earthquakes of long period of low frequency (LP) and of very low amplitude. There are no eruptions or volcanic tremors.

The level of the new acid lake continues to rise due to the amounts of precipitation and the marked decrease in the heat flow from the interior of the volcano to the surface.

The new acid lake has a temperature of about 55 degrees Celsius, an extreme acidity (pH = 0.23), a salinity greater than 200 mS / cm and a turbidity greater than 1000 UNF. The green color of the lake indicates the prevalence of iron minerals in reduced form and fine particles of colloidal sulfur (hydrothermal conditions).

The fumaroles are mainly found under the lake. The concentration of SO2 gas measured by the MultiGAS system at the western edge of the crater fluctuates at maximum values ​​of 10 parts per million, while the CO2 / SO2 ratio shows a tendency to remain around 1.0.

The field of sulfur-rich fumaroles in the NE sector continues to operate. In mouth A, bubbling and gas emissions are observed. On December 13, a low amplitude background tremor (2 to 4.5 Hz) is maintained, as are LP low amplitude earthquakes.

 

Sources: Ovsicori and RSN

Poas - 13.12.2019 / 15:56 - Ovsicori webcam

Poas - 13.12.2019 / 15:56 - Ovsicori webcam

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
 Shishaldin - 12.12.2019 The eruptive activity seen from Cold Bay. Photo courtesy of Aaron Merculief / via AVO

 Shishaldin - 12.12.2019 The eruptive activity seen from Cold Bay. Photo courtesy of Aaron Merculief / via AVO

A small eruption of Shishaldin in the Aleutian Arch produced a plume of ashes reaching 6000-7600 meters asl, dispersing to the northwest.

A burst of tremor was observed on December 12 at 7:10 a.m. local (4:10 p.m. UTC) and lasted 3 minutes, as well as lightning.

A flow is visible on the satellite images and on the photos taken from Cold Bay.

The volcano remains unstable and other explosions could occur.

 

Sources: AVO & Mirova

Shishaldin - Thermal anomalies at 12.12.2019 / 2.30 p.m. - Doc. Mirova_MODIS_Latest10NTI

Shishaldin - Thermal anomalies at 12.12.2019 / 2.30 p.m. - Doc. Mirova_MODIS_Latest10NTI

The Nevados de Chillan eruptive cycle continues, with this December 12, vulcanian explosions (overpressure in the lava dome) accompanied by plumes 2,000 meters high and minor pyroclastic flows on the northern flank.

The seismicity consists of VT earthquakes, LP earthquakes (linked to the explosions) and tremor.

The situation remains under the current orange alert.

 

Source: Sernageomin

Nevados de Chillan - 12.12.2019 - explosions with pyroclastic flows, respectively at 15:33 and 18:18 - webcam Sernageomin - a click to enlarge
Nevados de Chillan - 12.12.2019 - explosions with pyroclastic flows, respectively at 15:33 and 18:18 - webcam Sernageomin - a click to enlarge

Nevados de Chillan - 12.12.2019 - explosions with pyroclastic flows, respectively at 15:33 and 18:18 - webcam Sernageomin - a click to enlarge

The modest explosive activity continues in the summit craters of Mount Etna. These images, from the night of December 11 to 12, 2019, show a strombolian activity at the crater of Voragine, two mouths of the new southeastern crater (NSEC) and the crater northeast.

A novelty was the opening of a new small vent on the eastern flank of the "saddle cone" of the NSEC, which from the end of December 11 produced intermittent and weak strombolian activity, sometimes simultaneously and sometimes alternately with the more oriental mouth of the same NSEC.

Etna - Strombolian explosion at the eastern mouth of the NSEC at 1:10 a.m. (local time) on December 12, 2019 - photo INGV OE

Etna - Strombolian explosion at the eastern mouth of the NSEC at 1:10 a.m. (local time) on December 12, 2019 - photo INGV OE

Etna - explosion at the new mouth on the "cone of the saddle", recorded by the thermal camera on the Montagnola "EMOT" at 11:11 pm (local time) on December 11th. - Doc. INGV OE

Etna - explosion at the new mouth on the "cone of the saddle", recorded by the thermal camera on the Montagnola "EMOT" at 11:11 pm (local time) on December 11th. - Doc. INGV OE

A comment by Boris Behncke, from surveillance during the night of 11 to 12.12.2019

"It should be noted that these phenomena do not represent an increase in the intensity of eruptive activity, which, on the contrary, appears to have decreased slightly over the past two days, and the magnitude of the volcanic tremor has decreased considerably. since last night. Thus, L'Etna is once again asserting that the extremely versatile and mysterious volcano ... "

 

Sources: INGVvulcani and Boris Behncke

White Island - body recovery operations by NZ Defense Forces - photo NZ Police

White Island - body recovery operations by NZ Defense Forces - photo NZ Police

The level of the volcanic tremor has dropped, but remains high at Whakaari / White Island; no eruptions have occurred since December 9, and the alert level remains at 2.

According to the BBC, a team of 8 specialists from the New Zealand Defense Forces arrived by helicopter on the volcano, well equipped with protective suits and breathing apparatus (which somewhat lengthened their reconnaissance action).

The position of six people was known, and the bodies were taken to the north island. Efforts continue to locate the other two bodies, at least one of which is in the water, where divers are in action.

 

Sources: GeoNet updated alert bulletins # 8 and 9 - BBC News - Sentinel 2

White island - significant degassing this 12.12.2019 - sentinel image-2 bands 12,11,4 - one click to enlarge

White island - significant degassing this 12.12.2019 - sentinel image-2 bands 12,11,4 - one click to enlarge

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Publié le par Bernard Duyck
Publié dans : #volcanic activity

Volcano Sangay, in Ecuador, maintains a semi-continuous activity from two eruptive centers: the central crater and the Ñuñurco vent (southeast).

The central crater exhibits an explosive activity which generates small clouds of gas and ash. In the past month, emissions have reached 2 km high above the crater and have often gone northeast with great variability causing small ash falls in the provinces of Chimborazo, Morona Santiago and Azuay.

On the other hand, the Ñuñurco vent presents an effusive activity which results in an almost continuous emission of lava flows which settle along the south-eastern flank of the Sangay. At the margins of the lava flows are small rock falls (pyroclastic flows) which reach the basin and the upper channel of the Volcan river.

These deposits cause small temporary dams in the Volcán river, which are remobilized by the rains forming mudslides and debris (lahars).

Sangay - ash emissions towards Azuay y Cañar, in the south of the province of Morona Santiago - photo 11,12,2019 Cpt. François Kaizin

Sangay - ash emissions towards Azuay y Cañar, in the south of the province of Morona Santiago - photo 11,12,2019 Cpt. François Kaizin

Sangay - distribution of the ashes - Goes image -17 ABI of 11.12.2019 / 12:30 pm - Doc. NOAA / CIMES

Sangay - distribution of the ashes - Goes image -17 ABI of 11.12.2019 / 12:30 pm - Doc. NOAA / CIMES

This December 11, the emissions from Sangay were significant and concerned a large southwest sector, according to data from the GOES / NOAA satellite and a photo of Capt. François Kaisin flying over the Amazon.

 

The IGEPN recommends not to approach the dangerous zones of the Sangay volcano, the cone and the drainage.

 

Sources: IGEPN & local media

Sabancaya - 11.11.2019 / 10h22 - webcam Ingemmet / OVI

Sabancaya - 11.11.2019 / 10h22 - webcam Ingemmet / OVI

The INGEMMET, through its Vulcanological Observatory (OVI) identified at Sabancaya - Arequipa volcano, today Wednesday December 11, the occurrence of up to 06 small pyroclastic flows in a south-east direction, reaching up to 1 5 km from the crater; these are the first pyroclastic flows detected since the reactivation of the volcano.

In recent days, the Sabancaya has seen a slight increase in activity, recording larger plumes. It should be noted that Ingemmet warned of the likely occurrence of pyroclastic flows almost 2 months ago.

Faced with these events, the Vulcanological Observatory of Ingemmet recommends:

"Do not approach within 12 km of the crater of the volcano. Pyroclastic flows cause serious damage and human loss.

Stay away from streams / rivers that descend from the volcano, due to the potential location of lahars and pyroclastic flows.

Consult the volcano danger map.

Avoid exposing yourself to volcanic ash, which is harmful to your health. "

 

Source: Ingemmet / OVI

White island - photo 11.12.2019 / Jeannie Curtis

White island - photo 11.12.2019 / Jeannie Curtis

The alert level of Whakaari / White island has been revised to level 2, as there has been no pursuit of eruptive activity since December 9, BUT the volcanic tremor remains very high, suggesting a possibility of around 50-60% of future eruptive activity.

(GeoNet Bulletins # 6 and 7 12,12,2019)

White island drums -on 12.12.2019 at 7:18 a.m. and 8:30 p.m. NZDT - Doc. GeoNet
White island drums -on 12.12.2019 at 7:18 a.m. and 8:30 p.m. NZDT - Doc. GeoNet

White island drums -on 12.12.2019 at 7:18 a.m. and 8:30 p.m. NZDT - Doc. GeoNet

White Island - RSAM at 12.12.2019 / 20:25 NZDT - Doc. GeoNet

White Island - RSAM at 12.12.2019 / 20:25 NZDT - Doc. GeoNet

GNS Science has published a map of the access areas: the crater and the areas facing the notch remain prohibited, due to a possible eruption, or discharge of highly toxic gases.

White Island - 12.12.2019 - GNS staff access zones

White Island - 12.12.2019 - GNS staff access zones

The A.P. released a new provisional report on the dramatic eruption of December 9: a total of 16 killed, including 2 after hospitalization and 8 missing and considered dead. Many burn victims have a vital prognosis engaged.

 

Sources: GeoNet, GNS Science and local media.

What are the volcanic alert levels in New Zealand? GNS Science monitors all active volcanoes in New Zealand. Find out more here: https://www.geonet.org.nz/about/volcano/val

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Publié le par Bernard Duyck
Publié dans : #volcanic activity

Since about 4:00 am this December 11, the level of the volcanic tremor has increased significantly on the island of White island. This was accompanied by vigorous steam and mud thrown in several of the craters created by Monday's eruption.

GeoNet volcanologists interpret these signals as evidence of the continued high pressure of the gases inside the volcano. (GeoNet Volcanic Alert Newsletter Update # 4)

At 17:30, the level of volcanic tremor has continued to increase and is now at the highest level observed since the eruption of 2016.

All of this monitoring data to date, including yesterday's gas flight, suggests that the shallow magma inside the volcano is responsible for the tremor, gas flow, and jet activity. observed in the craters created during the eruption.

According to GeoNet experts, there is an average probability (40 to 60% chance) of a future eruption in the next 24 hours.

The volcanic alert level remains at level 3. (GeoNet Volcanic Alert Update # 5)

 

Source: GeoNet

 White Island - tremor variations between November 11 and December 11, 2019 - Doc. GeoNet

White Island - tremor variations between November 11 and December 11, 2019 - Doc. GeoNet

White island - seismicity 11.12.2019 / 08h48 NZDT - Doc. GeoNet

White island - seismicity 11.12.2019 / 08h48 NZDT - Doc. GeoNet

At Etna, four craters show activity between 2 and 8 December 2019 according to the INGV: Strombolian activity marks the Voragine, the Bocca Nuova and the new crater southeast, and the crater northeast.

From December 7, the amplitude of the tremor is on the rise.

Sulfur dioxide flows remain at a moderate level, and those of carbon dioxide in the soil have a slight tendency to increase. (INGV Weekly Etna Newsletter)

Etna - location of tremor sources - Doc. INGV bulletin 02 to 08.12.2019

Etna - location of tremor sources - Doc. INGV bulletin 02 to 08.12.2019

At NSEC level, there are small black ash puffs on December 9 and night glow, also visible at NEC and Voragine.

 

Sources: INGV OE and INGVvulcani

Etna NSEC - burst of ash on 09.12.2019 - photo INGVvulcani

Etna NSEC - burst of ash on 09.12.2019 - photo INGVvulcani

Etna - night glow at Voragine and NSEC on 09.12.2019 - photo INGVvulcani

Etna - night glow at Voragine and NSEC on 09.12.2019 - photo INGVvulcani

Etna - evening glow at Voragine and NSEC on 09.12.2019 - photo INGVvulcani
Etna - evening glow at Voragine and NSEC on 09.12.2019 - photo INGVvulcani

Etna - evening glow at Voragine and NSEC on 09.12.2019 - photo INGVvulcani

In Stromboli, the week of December 2 to 8 is characterized by explosive Strombolian activity, at an average rate of 12 hourly episodes (06.12) to 24 hourly episodes (08.12), accompanied by degassing and spattering. It is located in the north and south-central crater areas.

Seismicity and deformation do not show significant variations.

The sulfur dioxide flux remains at a medium-high level.

 

Source: INGV

Shaded relief of the Stromboli crater area obtained by image processing acquired by drone on July 9, 2019 (Collaboration with drone group GEOMAR Helmholtz Center for Ocean Research Kiel, Germany). At the top left of Stromboli Island, the black rectangle indicates the area of ​​interest, the black curved line and the red serrated line indicate, respectively, the morphological slope and the edges of the crater.

Shaded relief of the Stromboli crater area obtained by image processing acquired by drone on July 9, 2019 (Collaboration with drone group GEOMAR Helmholtz Center for Ocean Research Kiel, Germany). At the top left of Stromboli Island, the black rectangle indicates the area of ​​interest, the black curved line and the red serrated line indicate, respectively, the morphological slope and the edges of the crater.

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
WI tour operators landing to help 12 minutes after eruption on 09.12.2019 - photo M. Schade

WI tour operators landing to help 12 minutes after eruption on 09.12.2019 - photo M. Schade

A more accurate record of the eruption on White Island was made by the Police:

Out of the 47 people on the island,

- 5 are confirmed dead,

- 31 are still hospitalized, 27 of whom burned on at least 30% of their body and with a vital prognosis for many of them, 3 were able to leave,

- and 8 are missing and presumed dead (including 6 identified bodies).

Since December 10 in the morning, seismic activity has remained low, but we continue to see periodic jets of steam and gas from the active ventilation zone. The volcanic alert level remains at level 3. The aviation color code remains orange.

Over the next 24 hours, we still estimate an equal probability of no eruption or a smaller / similar size eruption that would impact the floor of the main crater, based on our observations and measurements.

 

As for the eruptive mechanism: "The eruption and the resultant vapor, also known as hydrothermal or phreatic eruption, can occur suddenly and with little or no warning. The expansion of the water into steam is at a supersonic speed and the liquid can reach 1,700 times its original volume. This produces catastrophic impacts.

Expansion energy is sufficient to break solid rock, dig craters, and eject rock fragments and ashes hundreds of meters from the vent. We know sites in New Zealand where materials have been blown more than 3 km from the vent by such eruptions. "

 

Source: GeoNet Volcano Newsletter Dec 10 2019 16:20 local - and local media.

Vidéo White island eruption 09.12.2019 - by Michael Schade / RNZ

Back to the rest of the news after this day of 09.12 dramatic ...

 

In Kamchatka, experts from the Kamchatka branch of the Russian Expert Council on Seismic Prediction, Seismic Risk and Risk Assessment (KF RES) concluded that the probability of an Avachinsky eruption during the month next has been increased. The conclusions are based on a set of geophysical and seismological data obtained in the Kamchatka branch of the Geophysical Service of RAS (KF Fitz EGS RAS).

On December 9, nighttime glow was observed on a crack.

The Avachinsky is located about thirty kilometers from Petropavlovsk. Its last eruption was in 2001 (GVP)

 

Source: Kam 24
 

News of White Island, Avachinsky, Sabancaya and Nevados de Chillan.
Sabancaya- plume rising to 4.200 meters on the 08.12.2019 / 11h36 - webcam IGPeru

Sabancaya- plume rising to 4.200 meters on the 08.12.2019 / 11h36 - webcam IGPeru

The eruptive activity of the Sabancaya volcano between 2 and 8 December 2019 remained at moderate levels, with the recording of an average of 22 explosions a day, moderate, and the consequent emission of ashes at a maximum height 4,200 meters.

During this period, 1,255 earthquakes were recorded, as well as 4 thermal anomalies, between 1 and 12 MW.

 

For the following week, the presence of a lava dome inside the crater of Sabancaya volcano leads to present three possible scenarios:

Scenario 1: corresponds to a mild to moderate explosive activity such as that recorded by Sabancaya in recent years, associated, of course, with the slow growth or rise of the lava dome.

Scenario 2: Growth and collapse of the lava dome with generation of low volume pyroclastic flows.

Scenario 3: corresponds to effusive eruptions related to the location of lava flows.

In the event of volcanic explosions with ash emissions, they will disperse on December 9 to the western sector of the volcano with winds that reach 50 km / h. Between December 10th and 16th, the winds would scatter ashes to the southeast sector of the volcano with winds up to 50 km / h.

 

Source: I.G.Peru

Sabancaya - summary of the activity between 2 and 8.12.2019 - Doc. IG Peru

Sabancaya - summary of the activity between 2 and 8.12.2019 - Doc. IG Peru

In Chile, Nevados de Chillan continues its explosive activity, starting from four emission centers in the Nicanor crater, and effusive, without any known advance of the flows. The seismicity of the last 24 hours is moderate, and characterized by volcano-tectonic earthquakes, earthquakes LP (in relation with the explosions) and VLP and tremor.

 

Sources: Sernageomin & Onemi

Nevados de Chillan - map of risk areas updated on 08.12.2019

Nevados de Chillan - map of risk areas updated on 08.12.2019

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
White island - phreatic eruption this 09.12.2019 / 14h11 - photo Michael Schade / Twitter

White island - phreatic eruption this 09.12.2019 / 14h11 - photo Michael Schade / Twitter

2019.12.09 White island - Zurraspismo Twitter

2019.12.09 White island - Zurraspismo Twitter

A phreatic eruption occurred on December 9 around 14:11 local time on White Island in northern New Zealand. This short-lived impulsive event affected the bottom of the crater. Activity seems to have decreased since the eruption.

Monitoring data shows that there was a short-lived eruption that generated an ash plume at about 3,600 meters above the vent. Ashes covered the floor of the main crater, where there were about fifty people. We regret the death of one person, and many others burned. The balance sheet could get heavier in the next few hours as people go missing.

Seven helicopters joined the island just after the eruption to bring relief and evacuate the wounded to the nearest hospitals.

The fall of the ashes seems to be limited to the island and we do not expect a smaller amount of ash to reach the Eastern Cape in the next hours.

Monitoring equipment is still functioning and a steady decline in activity has been observed since the eruption. There is still a great deal of uncertainty about future changes, but currently there is no sign of escalation.

After a temporary elevation at 14:30 local at alert level 4 and orange code, the GeoNet lowered the alert level to 3 to 16:25 local.

Aerial view of White Island after the eruption - New Zealand Herald photo via AP / George Novak 09.12.2019

Aerial view of White Island after the eruption - New Zealand Herald photo via AP / George Novak 09.12.2019

Professor Shane Cronin, Volcanologist, University of Auckland, comments:

"Sudden and unplanned eruptions of volcanoes such as White Island can be expected at any time. Magma is close to the surface, and heat and resulting gases heat surface and groundwater to form strong hydrothermal systems. We know that hydrothermal and phreatic eruptions can occur suddenly and with little or no warning because they are caused by the expansion of superheated water into steam.

The expected dangers of such events are the violent ejection of hot blocks and ashes, and the formation of currents "similar to hurricanes of wet ashes and coarse particles that radiate from the blast mouth. These can be fatal in terms of impact trauma, burns and breathing problems. Eruptions are short-lived, but once they occur, there is a good chance that others will occur, usually smaller, as the system rebalances. "
 

Update :

The NZ Herald in its edition of 19:02 this December 9 mentions five people dead and the police expect that the death toll will increase. Twenty-three people were transported from the island, all with some degree of burns. A number of them were taken to hospitals in Whakatane and Middlemore.

There are still a number of people on the island who are missing. New Zealanders and overseas tourists, including some of the Ovation of the Seas cruise ship that was visiting Tauranga. would be involved. The cruise ship will not leave the port before the return of the missing passengers.

A damaged and ash-covered helicopter near the crater was also seen near the edge of the island.

The deputy commissioner of the national operation commander said he was not sure if he could pick up those who had not been found yet. "At this point, it is too dangerous for the police and rescue to reach the island ... the island is currently covered with ash and volcanic materials."

Sources: GeoNet - NZ Radio - National Police - On-site observers, including Michael Schade and Zurraspismo - local media including NZ Herald
 

 White island west rim 09.12.2019 14h30-14h40 NZDT - photos Inst. og geological and nuclear sciences ltd - one click to enlarge
 White island west rim 09.12.2019 14h30-14h40 NZDT - photos Inst. og geological and nuclear sciences ltd - one click to enlarge

White island west rim 09.12.2019 14h30-14h40 NZDT - photos Inst. og geological and nuclear sciences ltd - one click to enlarge

White island A damaged and ash-covered helicopter near the crater was also seen near the edge of the island. - from vidéi ofg Michael Schade

White island A damaged and ash-covered helicopter near the crater was also seen near the edge of the island. - from vidéi ofg Michael Schade

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Etna NSEC - Strombolian activity of 07.12.2019 / 22:10 of the Mareneve road near the village of Fornazzo on the eastern flank of Etna - photo INGVvulcani

Etna NSEC - Strombolian activity of 07.12.2019 / 22:10 of the Mareneve road near the village of Fornazzo on the eastern flank of Etna - photo INGVvulcani

From 18:00 UTC on 6 December, the cameras of the CCTV system of the INGV show, in addition to the Voragine / Bocca Nuova activity, a gradual intensification of Strombolian activity at the New Crater of South-East of the Etna, who manifested already from 16:00 UTC with weak and discontinuous explosions. The activity produces, for the moment, the fallout of incandescent material along the slope of the cone. An increase in the tremor is observed around 22:10 local.

Etna NSEC- 07.12.2019 / 19:27 - INGV webcam Emov0389


This activity continued on December 7, marked by thermal anomalies between 71 and 169 MW, according to Mirova.

December 8, values ​​of 54 and 144 MW are recorded at 0:15 and 1:50. This morning, ashes are emitted by the crater northeast.

 

Sources: INGV OE, INGVvulcani and local observers.

Etna tremor - at 08.12.2019 / 4:10 - Doc. INGV EMFS velocimeter - HHZ - RMS

Etna tremor - at 08.12.2019 / 4:10 - Doc. INGV EMFS velocimeter - HHZ - RMS

Etna - thremical anomalies at 08.12.2019 / 01h50 - Doc. Mirova_MODIS_Latest10NTI

Etna - thremical anomalies at 08.12.2019 / 01h50 - Doc. Mirova_MODIS_Latest10NTI

In the Aleutian arc, an eruption was detected on December 7th in Semisopochnoi, starting at 0h26 AKST, with an episode of strong tremor and the emission of infrasound.

Cloud cover around 3,000 meters prevented the detection of an ash plume of greater height.

The aviation code and the alert level were increased respectively at Orange & Watch.

Intermittent explosions continued during the night, and seismicity remains high.

No surface activity or significant ash emissions were observed.

 

Source: AVO

Semisopochnoi - photo archives AVO /  Clifford Roger

Semisopochnoi - photo archives AVO / Clifford Roger

A moderate eruptive activity continues in Ebeko, in the northern Kuriles. It is characterized by explosions generating a plume of ashes high of 2500-2700 meters asl, drifting towards the northeast of the volcano.

The continuation of the activity justifies the maintenance of the orange aviation code, explosions accompanied by ashes that can occur at any moment and reach up to 6000 meters asl.

 

Sources: KVERT & VAAC Tokyo

Ebeko - Videodata by IMGG RAS FEB and KB GS RAS 27.07.2019

Ebeko - Videodata by IMGG RAS FEB and KB GS RAS 27.07.2019

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Etna - situation of the VOR & BN on 06.12.2019 - photo Piero Berti, via J.Nasi / Butterfly Helicopters / INGVvulcani

Etna - situation of the VOR & BN on 06.12.2019 - photo Piero Berti, via J.Nasi / Butterfly Helicopters / INGVvulcani

Etna - situation of the VOR & BN on 06.12.2019 - photo Piero Berti, via J.Nasi / Butterfly Helicopters / INGVvulcani

Etna - situation of the VOR & BN on 06.12.2019 - photo Piero Berti, via J.Nasi / Butterfly Helicopters / INGVvulcani

At Etna, since the 6th of December in the morning, a Strombolian activity marks the Voragine and a new lava flow is observed from the base of the cone of slag located in this crater; lava waterfall in the Bocca Nuova. INGV reports that this phenomenon has already been observed on 18-20 September2019.

An explosion is recorded by the thermal camera at the eastern mouth of the new southeastern crater / NSEC.

 Etna - Hot spots at crater NE, Bocca Nuova and Voragine; low spot at NSEC - Sentinel-2 L1C image on 2019-12-04 bands 12,11,4

 Etna - Hot spots at crater NE, Bocca Nuova and Voragine; low spot at NSEC - Sentinel-2 L1C image on 2019-12-04 bands 12,11,4

Etna NSEC - 06.12.2019 / 09:28 - Etna Webcam therm EMOT - INGV OE

Etna NSEC - 06.12.2019 / 09:28 - Etna Webcam therm EMOT - INGV OE

From 18:00 UTC, CCTV cameras show a gradual intensification of strombolian activity at the New Southeast Crater, which has already manifested itself since 16:00 UTC with weak and discontinuous explosions. The activity produces, for the moment, the fallout of incandescent material along the slope of the cone.

An increase in the tremor is observed around 22:10 local.

 

Sources: INGV vulcani and Piero Berti photos (aka Joseph Nasi), Butterfly Helicopters s.r.l.

Etna - Strombolian activity 06.12.2019 / 19h34 at NSEC (right) and weaker explosions at Voragine (left) - photo INGVvulcani

Etna - Strombolian activity 06.12.2019 / 19h34 at NSEC (right) and weaker explosions at Voragine (left) - photo INGVvulcani

Etna - thermal anomalies on 07.12.2019 / 01h10 - Doc. Mirova Modis

Etna - thermal anomalies on 07.12.2019 / 01h10 - Doc. Mirova Modis

 Etna - tremor at 07.12.2019 - Doc. INGV OE

Etna - tremor at 07.12.2019 - Doc. INGV OE

In the Izu-Bonain Volcanic Arc, the Nishinoshima Volcano, which has been calm since July 2018, has recovered explosive-effusive activity since 4 December 2019.

The explosions are located at the main cone, and a vent that opened at the NE base of the cone produces spaterring and lava flows.

This activity, in addition to the thermal anomalies recorded by satellite, was observed on December 6 during an overflight by the Japanese coastguard.

 

Sources: Japan Coast Guards, JMA and Mirova

Nishinoshima - 06.12.2019 - photo Japan Coast Guards

Nishinoshima - 06.12.2019 - photo Japan Coast Guards

Nishinoshima - 06.12.2019 - photo Japan Coast Guards

Nishinoshima - 06.12.2019 - photo Japan Coast Guards

In Indonesia, the Karangetang South Crater shows sustained activity, with incandescent projections at 50 m height. The lava descends towards Kali Batang and West Beha until about 800 - 1000 m, until Kali Sense, Nanitu, Sesepe and Pangi, until about 1000 - 1500 m.

Le cratère nord est lui aussi actif et présente de l'incandescence.

Karangetang - image Sentinel-2 bands 12,11,4 from 05.12.2019

Karangetang - image Sentinel-2 bands 12,11,4 from 05.12.2019

 Karangetang - Thermal anomalies at 07.12.2019 / 5.25 - Doc. Mirova_MODIS_Latest10NTI

 Karangetang - Thermal anomalies at 07.12.2019 / 5.25 - Doc. Mirova_MODIS_Latest10NTI

Le PVMBG renseigne pour ce 5 décembre :

87 séismes d’avalanches
13 séismes liés aux explosions .
2  séismes Hybride
10 tremblements de terre volcaniques peu profonds
1 tremblement de terre volcanique
1 séisme ressenti (échelle 1 MMI)
5 grands séismes tectoniques
2 épisode de trémor harmoniques
et du Tremor continu, d'amplitude 0,5-7 mm (valeur dominante 5 mm).

 

Sources : PVMBG, Mirova et Sentinel-2

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