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Earth of fire

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

Articles avec #actualites volcaniques catégorie

Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

Longevity and endurance of monuments built in ancient Rome 2,000 years since come to be understood and explained by scientists ... at their base, a concrete made of volcanic ash!

The team of researchers from the Department of Energy's Berkeley Lab. analyzed the concrete walls of Trajan's Market, built in the 2nd century on the slopes of the Quirinale in Rome. It consists of coarse pieces of brick and tuff (45-55 vol.%), linked by a mortar of lime and volcanic ash.

To 1 century, the Romans improved the hydraulic binders, adding volcanic ash of Pozzuoli, in Campania. Vitruvius, a Roman architect, evidenced in his "De Architectura", a treatise on architecture in ten books and in Latin.

 

Rome - Trajan's Market - photo Vincenzo Pinto / Agence France-Presse / Getty Images

Rome - Trajan's Market - photo Vincenzo Pinto / Agence France-Presse / Getty Images

Rome - Trajan's Market, the walls in "Roman concrete" - photo Marie Jackson

Rome - Trajan's Market, the walls in "Roman concrete" - photo Marie Jackson

Sample of "Roman concrete" - Photo: Roy Kaltschmidt, Berkeley Lab.

Sample of "Roman concrete" - Photo: Roy Kaltschmidt, Berkeley Lab.

This mortar resistant to micro-fracturing through the in situ crystallization of strätlingite pads, a hydrated silicate of aluminum and calcium, Ca2Al2SiO7.8H2O formula, which reinforces the interface areas and the cementitious matrix.

According to Marie Jacson, formation of volcanologist : "dense tangles of lamellar crystals hinder the propagation of cracks and preserves the cohesion on a micron scale, which allows the concrete to maintain its chemical resilience and structural integrity in an active seismic
environment across the millennium."

Strätlingite - tabular white crystals of stratlingite - Doc. Review in Mineralogy and Geochemistry

Strätlingite - tabular white crystals of stratlingite - Doc. Review in Mineralogy and Geochemistry

Mortars binding the components of the concrete used in Imperial Rome are of great interest, not only because of their durability and resilience, but also for the environmental benefits they offer.

This mortar is made from a blend of a melting to 85% by vol. of volcanic ash,  and water and lime, calcined at a temperature lower than that used to make the modern Portland cement (the latter requires the heating of clay and limestone mixture at 1450 ° C, which process releases 7% of the amount of carbon emitted into our atmosphere every year) ... we could get to a significant reduction in carbon emissions, and increase the quality of concrete, incorporating a substantial volume of volcanic rocks in the production of special concrete.

 

Sources :

- Back to the Future with Roman Architectural Concrete - Research at Berkeley Lab’s Advanced Light Source Reveals Key to Longevity of Imperial Roman Monuments - link

- iO9 - How the ancients Rolans made better concrete than we don now - link

- Minaral data - Strätlingite - link

- Strätlingite - photo link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

As part of a study by NOAA Ocean Explorer / Submarine ring of fire in 2014, a new Seamont is found erupted on December 14 in the Mariana volcanic arc.
 



 

3D bathymetric of seamount Daikoku - Doc. NOAA Ocean Explorer

3D bathymetric of seamount Daikoku - Doc. NOAA Ocean Explorer

 Comparative bathymetries of the top of Daikoku in 2003 and in December 2014 - a large crater formed at the top - Image courtesy of Submarine Ring of Fire 2014 - Ironman NSF / NOAA.

Comparative bathymetries of the top of Daikoku in 2003 and in December 2014 - a large crater formed at the top - Image courtesy of Submarine Ring of Fire 2014 - Ironman NSF / NOAA.

Daikoku summit Cross section with the results of the CTD, showing a high turbidity of the eruptive plume (warm colors = high particle concentration) - Image courtesy of Submarine Ring of Fire 2014 - Ironman, NOAA / PMEL, NSF.

Daikoku summit Cross section with the results of the CTD, showing a high turbidity of the eruptive plume (warm colors = high particle concentration) - Image courtesy of Submarine Ring of Fire 2014 - Ironman, NOAA / PMEL, NSF.

Underwater bathymetric map of Northern Mariana arc, established by NOAA in 2006 - the Daikoku seamount is at the bottom right.

Underwater bathymetric map of Northern Mariana arc, established by NOAA in 2006 - the Daikoku seamount is at the bottom right.

Other shipping mapped the entire arc of the Marianas in 2003 ... over 60 seamounts were discovered by sonar.

Since then, various eruptions have marked this area: the South Sarigan seamount erupted in 2010, and Ahyi seamount in April-May 2014; by cons, the activity observed in 2004 at NW Rota has ceased.

In December 2014, the seamount Daikoku, previously considered to be of a hydrothermal activity seems to be erupting in turn.

In support of these suspicions, the observation of strong plumes from the summit of this submarine volcano, with a high turbidity, low pH, abnormalities in reduced chemicals products, and high levels of hydrogen. In addition, the multibeam sonar confirms the presence of a large new crater at the summit of the cone, 150 meters wide and 100 meters deep.

 

Daikoku - molten sulfur pool - Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program

Daikoku - molten sulfur pool - Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program

Because of the bad weather, a ROV control has not have been obtained ... but in 2006 diving ROV was used to visualize a molten sulfur pool, of black color due to its high content of iron, bubbling at the bottom of a small crater, 420 meters below the summit of Daikoku. This basin was surrounded by flatfish, including a new endemic species ... these may have disappeared following the latest eruption.
 

Daikoku seamount - sulfur crust sampled by the ROV Jason in 2006 - Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program

Daikoku seamount - sulfur crust sampled by the ROV Jason in 2006 - Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program

Sources :

- NOAA Ocean Explorer - Daikoku seamount erupting - link

- NOAA Ocean Explorer - Submarine Ring of Fire 2006 - link

- Global Volcanism Program - Daikoku

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

The deep hydrothermal vents present in the oceans are getting better studied since the late 70s; they reveal not only a complex chemical trade but also a living environment, from bacteria to more advanced marine organisms.
 

Molluscs and crabs living on hydrothermal vents - photo ns.umich.edu

Molluscs and crabs living on hydrothermal vents - photo ns.umich.edu

Of these, a little devil, known as the "little devil blob" or, more scientifically, Aciduliprofundum boonei ... a archaeobacterium living in extreme environment formed by the top of hydrothermal vents: in acidic medium, pH between 3.3 and 5.8, at a temperature between 55 and 75 ° C, this single cell organism derives its energy from the reduction of iron and sulfur, and the oxidation of organic carbon.
 

Aciduliprofundum boonei, aka "little devil blob" - photo vanderbilt.edu

Aciduliprofundum boonei, aka "little devil blob" - photo vanderbilt.edu

Hydrothermal vent in the Lau Basin / West Pacific - Image credit MARUM - University of Bremen - NOAA Pacific Marine Environmental Laboratory.

Hydrothermal vent in the Lau Basin / West Pacific - Image credit MARUM - University of Bremen - NOAA Pacific Marine Environmental Laboratory.

But it has another peculiarity: it has an anti-bacterial gene, which could be a source of new antibiotics in the future, and to help the medicine facing increasing resistance and research in this area slipping a bit.

The DNA analysis showed that Aciduliprofundum boonei has a gene that produces lysozyme, able to kill resistant bacteria such as Staphylococcus aureus, Bacillus anthrax or Clostridium difficule.

What justifies the presence of this enzyme ? The living environment of the archaeon : she lives in biofilms in promiscuity with extremophile bacteria, and must compete with them for resources.

Besides an increase in the study of the evolution of living organisms, volcanoes will help humanity to solve a vital health issue ... however, some years may separate the discovery from a practical application.

Source :

Vanderbilt University - Life’s extremists may be an untapped source of antibacterial drugs - link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

The Japanese Meteorological Agency raised the alert level of the volcano Tokachidake 1 and 2, accompanied by a prohibited area of 1 km. 62-2 around the crater. This is the first time since December 2008 that the volcano alert level is increased, for fear of a possible eruption "small scale".

Since July 2014 there have been a number of changes in the rates of seismic activity in the region. For example, in September 2014, there were volcanic tremors, lasting for almost 22 minutes.

Tokachidake - 12/16/2014 Photo xanthous.jp2014.12.16 Twitter

Tokachidake - 12/16/2014 Photo xanthous.jp2014.12.16 Twitter

The volcanoes of Hokkaido - Doc. GSJ / AIST

The volcanoes of Hokkaido - Doc. GSJ / AIST

The Tokachidake consists of a group of andesitic stratovolcanoes, and lava domes, oriented NE-SW on a tuff plateau of Pleistocene. It is located in the center of Hokkaido, north of the Japanese archipelago. Many of explosion craters and cinder cones are scattered on the upper flanks, the active centers being located at the northwest end of the chain.

Since the mid-19th century, frequent phreatic type eruptions were recorded. The most important were held in 1926 and 1962.

The eruption of 1926-1928 was accompanied by the collapse of the central cone and a debris avalanche. A lahar descended the Biei and Furano rivers, reaching the town of Kami-Furano, 25 km from the volcano, killing hundreds of people. Pyroclastic deposits is estimated at 13,000 and those of collapseof  the cone between 2 and 4 million m³.

 

The summit craters of Tokachidake - Doc. Geological Survey of Japan

The summit craters of Tokachidake - Doc. Geological Survey of Japan

Tokachidake - From the front to the background, Kitamuki craters, Suribachi, Ground crater with at his right, the crater 62-2, and the summit in the background - The 62-2 crater shows a  fumarolic activity - Photo H.Seo 2007 / Geological Survey of Japan

Tokachidake - From the front to the background, Kitamuki craters, Suribachi, Ground crater with at his right, the crater 62-2, and the summit in the background - The 62-2 crater shows a fumarolic activity - Photo H.Seo 2007 / Geological Survey of Japan

  Topography of Tokachidake group - the top of Tokachidake in the center - Doc. K.Nakajima / GSJ

Topography of Tokachidake group - the top of Tokachidake in the center - Doc. K.Nakajima / GSJ

The eruption in 1962 took his seat in the new "crater 62", located on the western edge of the Ground crater. The eruption column reached 12,000 meters and covered with ash the entire eastern Hokkaido and southern Urup island at 650 km.

Following the eruption, a pyroclastic cone was formed and five craters, called 62-0 to 62-4. Only 62-2 and 62-3 craters resisted, others were buried under subsequent deposits.

The eruption of 1988-1989, sitting at 62-2 crater, had first a phreatic phase, followed by a second phase phreatomagmatic accompanied by ash fallout to Abashiri, on the coast of the Sea of Okhotsk. The following ash falls were distributed on ESE - SE of the volcano.

The GVP reported last eruptive activity from February to April 2004.

Tokachi-Dake, zenithal view of 62-2 crater, left and right, of 62-3 crater - photo H.Seo 2007 / GSJ

Tokachi-Dake, zenithal view of 62-2 crater, left and right, of 62-3 crater - photo H.Seo 2007 / GSJ

Tokachidake - the central crater is contiguous with the 62-2 crater formed in 1962, with a fumarolic activity - photo Ishizuka 1995 / GSJ

Tokachidake - the central crater is contiguous with the 62-2 crater formed in 1962, with a fumarolic activity - photo Ishizuka 1995 / GSJ

Sources :

- Xanthous - link

- Geological Survey of Japan - Quaternary volcanoes - Tokachidake volcano

- Global Volcanism Program - Tokachidake


 

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Nevado del Ruiz - ash plume on 2014.12.15 - photo Jaime Eduardo Benavides / Observatorio Vulcanologico sismologico to Manizales

Nevado del Ruiz - ash plume on 2014.12.15 - photo Jaime Eduardo Benavides / Observatorio Vulcanologico sismologico to Manizales

In Colombia, the Nevado del Ruiz introduced during the period between 2 and December 8, strong seismic activity, volcano-tectonic type related to the fracturing of rocks, LP earthquakes and tremor. Earthquakes were located northeast of Arenas crater at a depth of 1 to 4 km. The observatory of Manizales recorded a continuous deformation.

On December 15 at 7:38 local, a seismic signal corresponding to the emission of ash was confirmed by direct observations and webcam images. The ashes are falling on the western side of the volcano, and caution is recommended in the drainages of the rios Molinos, La Marcada, Guali, Azufrado and Lagunillas, and on the road from Manizales to Murillo. The alert level remains at Amarillo III / Cambios en el comportiamento of actividad volcanica.

source:
Observatorio Vulcanologico there sismologico Manizales - Boletín del Volcán Actividad Extraordinario of Nevado del Ruiz, Emisión confirmada de Ceniza, 15 de Diciembre 2014 8:15 am -
link

Sinabung - pyroclastic flow of 12.09.2014 / 4:56 p.m. - photo endrolew@

Sinabung - pyroclastic flow of 12.09.2014 / 4:56 p.m. - photo endrolew@

On Sumatra, the eruption of the Sinabung continues. The extrusion of a viscous lava lobe on the south side and his partial collapse causing pyroclastic flows from small to medium size. Ash plumes are identified, amount up to 6 km. high these days.

Based on this activity, the aviation code has turned red Dec. 14 (VAAC Darwin)

 

Sinabung - the lava dome involved in collapses and pyroclastic flows - photo Beidar Sinabung

Sinabung - the lava dome involved in collapses and pyroclastic flows - photo Beidar Sinabung

Sinabung on 12/11/2014 - Photo Digital Globe via volcano alert - pic.twitter.com-nxRqZ771HZ

Sinabung on 12/11/2014 - Photo Digital Globe via volcano alert - pic.twitter.com-nxRqZ771HZ

Sinabung - co-pyroclastic cloud 12.15.2014 / 5:58 p.m. - photo Beidar Sinabung

Sinabung - co-pyroclastic cloud 12.15.2014 / 5:58 p.m. - photo Beidar Sinabung

In Iceland, the Holuhraun lava field always extends: it reached 78.6 km² on December 12 and no more kipuka is free of lava.

December 15 at 9:26, an earthquake of M 5.4 rocked the northern edge of the caldera of Bárðarbunga. The IMO reported about 40 earthquakes in the caldera in the last 24 hours, including five of M4-5 and ten of M 3-4. The eruptive dyke is rocked by ten earthquakes.


 

Holuhraun - the lava lake within its ramparts on 12/11/2014 - photo Iceland online

Holuhraun - the lava lake within its ramparts on 12/11/2014 - photo Iceland online

Holuhraun - evolution of the lava field between 2 and 12 December 2014 - Doc IES / IMO

Holuhraun - evolution of the lava field between 2 and 12 December 2014 - Doc IES / IMO

Bárðarbunga - earthquake location of 15.12.2014 between midnight and 17:50 - Doc. IMO

Bárðarbunga - earthquake location of 15.12.2014 between midnight and 17:50 - Doc. IMO

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Fogo - 12.10.2014 - desolate landscape in Cha das Caldeiras - photo Waldemar Pires

Fogo - 12.10.2014 - desolate landscape in Cha das Caldeiras - photo Waldemar Pires

Twenty-three days after the start of the eruption, the volcano Fogo seems to calm down ... for seven days, the emissions of gases and ash are falling and the lava flow is stagnant, according to the official news agency Lusa.

The lava flow remains at a little over 600 meters of Bangeira (Saturday), and 3,500 meters of Fernão Gomes (situated at an altitude of 1,900 meters), the "critical point of slope failure", opening a descent without obstacle to the coastal villages, where Cutelo Alto and Fonsaco are in sight.

This information is contradicted on this Sunday, where the investigation GEOVOL Group reports that the lava flows laterally in areas where cooling casting has weaknesses. Sulfur dioxide emissions were measured by Involcan to 9,000 tonnes per day on 13.12. Fogo News reports lava flow heading Cova Tina, south-west of the eruptive site, and invading farmland.

 

Reporting by scientists from the University of Cape Verde / RTC Tv

Fogo : eruption seems to calm down!

In front of the unpredictability of the volcano, the Coordinating Bureau of the Cape Verdean Government continues to implement the emergency plan for the north of the island, to be ready to react in case of worsening of the situation...About 2300 people are on alert for evacuation if necessary.

 

Extensive destruction in the villages of Cha das Caldeiras. - Photo Alcindo Montornd

Extensive destruction in the villages of Cha das Caldeiras. - Photo Alcindo Montornd

Meanwhile, the humanitarian assistance ongoing to reach Fogo... two giant Ilyushin 76 cargo planes have landed on the island of Sal, loaded with six tons of support materials. They allow an eventual evacuation to São Filipe.

A ship left Angola with more than 9,000 tonnes of food aid, and housing construction kits.

The Government of Cape Verde is now focusing on the relocation of thousands of displaced people after the destruction of Portela and Bangueira villages, and the creation of sources of revenue for families in the agricultural zone of Cha das Caldeiras.

 

OCHA map with the location of displaced by the eruption of Fogo - doc OCHA 11/12/2014

OCHA map with the location of displaced by the eruption of Fogo - doc OCHA 11/12/2014

The lava stagnates after the eruption of Fogo - photo Avcan 13/12/2014

The lava stagnates after the eruption of Fogo - photo Avcan 13/12/2014

Sources :

- Sapo / Lusa - Vulcão do Fogo continua "adormecido", mas imprevisibilidade mantém-se - link

- Fogo News  - Actividades vulcânica abranda mas o alerta da Protecção Civil para Cutelo Alto e Fonsaco mantém-se

- OCHA - Cabo Verde / Fogo volcano emergency situation report - link

- RTC Tv - reportage

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Hawaii - The head of the new active lobe of the June 27's lava flow, follows a sloping path towards Pahoa Marketplace - Photo HVO December 12, 2014

Hawaii - The head of the new active lobe of the June 27's lava flow, follows a sloping path towards Pahoa Marketplace - Photo HVO December 12, 2014

The lava flow called "June 27", powered by the Pu'u O'o system and located in the east rift zone of Kilauea, again threatening the village of Pahoa, following the creation of a new active lobe between the inspections of 24 November and 1 December.

The Civil Defense and the Hawaii Volcano Observatory reported that the head of a lobe of the June 27's lava flow is just 2700 meters from the intersection of Highway 130 and the  Pahoa
village road.

Since 9 December, she has advanced 900 meters, which characterizes the ratio of advance of 320 meters per day. This lobe takes a path that leads steeply on this road intersection near Pahoa Marketplace ... that would be achieved at constant speed in a week.

 

Hawaii - June 27's lava flow - position of the new active lobe, on 1 December compared with the old part of the cast becoming inactive - photo and annotations HVO

Hawaii - June 27's lava flow - position of the new active lobe, on 1 December compared with the old part of the cast becoming inactive - photo and annotations HVO

Hawaii - advance of June 27's lava flow - on top map: the 12/09/2014 - map below: 12/12/2014 - Doc. HVO
Hawaii - advance of June 27's lava flow - on top map: the 12/09/2014 - map below: 12/12/2014 - Doc. HVO

Hawaii - advance of June 27's lava flow - on top map: the 12/09/2014 - map below: 12/12/2014 - Doc. HVO

In addition to this active lobe, a breakout in the lava tunnel remains weakly active since December 5, at 2600 meters of Pu'u O'o.

This breakout is about 1,000 meters long, and has expanded the flow field in this area of about 200 meters.

 

Hawaii -  breakout in the June 27's lava flow, near the Pu'u O'o - photo HVO

Hawaii - breakout in the June 27's lava flow, near the Pu'u O'o - photo HVO

Source:

HVO / Hawaiian Volcano Observatory - report and pictures

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Aerial view of Azuma Group: Issaikyoyama to the left and the Azuma-Kofuji to the right - in the foreground, Lake Kamanuma - photo H.Yagi / Geological Survey of Japan

Aerial view of Azuma Group: Issaikyoyama to the left and the Azuma-Kofuji to the right - in the foreground, Lake Kamanuma - photo H.Yagi / Geological Survey of Japan

Azuma volcano in Fukushima Prefecture, Tohoku region (on the island of Honshu, Japan), is passed in vigilance from level 1 to 2.

The Japan Meteorological Agency observed, on December 12 in the afternoon, volcanic earthquakes associated with magma movement; they are increasing. Inflation of the area west of the crater was also observed, on database of inclinometers ... therefore access near the crater was banned, an eruption is likely to occur.

Thank you Shérine France
for the info and translation.
 

The pyroclastic cone Azuma-Kofuji - photo Twitter / B4pM-goCYAAM55h

The pyroclastic cone Azuma-Kofuji - photo Twitter / B4pM-goCYAAM55h

On the left, the location of Azuma,one of the many volcanoes of Japan - Doc. USGS / Lyn Topinka - right, tectonics of the Japan volcanic arc - Doc. Andrew James Martin et al. in ref sources - one click to enlarge.On the left, the location of Azuma,one of the many volcanoes of Japan - Doc. USGS / Lyn Topinka - right, tectonics of the Japan volcanic arc - Doc. Andrew James Martin et al. in ref sources - one click to enlarge.

On the left, the location of Azuma,one of the many volcanoes of Japan - Doc. USGS / Lyn Topinka - right, tectonics of the Japan volcanic arc - Doc. Andrew James Martin et al. in ref sources - one click to enlarge.

The volcanic group Azuma, or Azumayama, consists of a series of overlapping stratovolcanoes of shield volcanoes, lava domes and pyroclastic cones. It is subdivided into two subgroups, Nishi-Azuma and Higashi-Azuma, the latter including Issaikyou-Zan and Azuma-Kofuji.
The complex basaltic, andesitic and dacitic, was built in two rows east-west oriented on an underbody of sedimentary rocks and granodiorite of
Tertiary, west of Fukushima city ... became since infamous.

Volcanic activity then shifted to the east, with the Higashi-Azuma group.

Beautiful pictures of Azuma group on the site VolcanoDiscovery - courtesy of Tom Pfeiffer. - http://www.volcanodiscovery.com/azuma-images.html

Beautiful pictures of Azuma group on the site VolcanoDiscovery - courtesy of Tom Pfeiffer. - http://www.volcanodiscovery.com/azuma-images.html

Craters of the "young" Azuma - according to Yamamoto T. (2005) Eruptive history of Azuma volcano, NE Japan, DURING last 7,000 years.

Craters of the "young" Azuma - according to Yamamoto T. (2005) Eruptive history of Azuma volcano, NE Japan, DURING last 7,000 years.

Historical eruptions, mostly small phreatic eruptions (VEI 1-2), are assigned to the vent Issaikyo, located at the north end of the link group Higashi. - link

In 1893, two geologists were killed by falling bombs on Azuma. His last official rash, a steam explosion at O-ana crater in the southeastern part of the Issaikyo, in 1977, lasted after only one day. In April-May 2001, a seismic swarm marked the Azuma volcano.

The Azuma-Kofuji crater, although symmetrical, the crater lakes Goshikinuma and Okenuma, and fumaroles area on the flanks of the Issaikyo are popular tourist destinations.

 

Azuma - fumarolic activity on the west wall of the O-ana crater - photo S.Nakano / GSJ

Azuma - fumarolic activity on the west wall of the O-ana crater - photo S.Nakano / GSJ

Sources :

- Tweet de shérine France - réf JMA

- Volcanodiscovery - Azuma - link

- Petrologic characteristics of the newest stage in Azuma volcano group, Northeast Japan  - by Masao Ban & al. - link

- Tectonic shortening and coeval volcanism during the Quaternary, Northeast Japan arc - Koji Umeda & al. - link

- Application of the Bayesian Approach to Incorporate Helium Isotope Ratios in Long-Term Probabilistic Volcanic Hazard Assessments in Tohoku, Japan - By Andrew James Martin, Koji Umeda and Tsuneari Ishimaru - link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

Satellite images related thermal anomalies on various volcanoes of the Kuril archipelago since early December.

The SVERT, the Sakhalin Volcanic Eruption Response Team, points out this anomaly
- between 2 and 5 December and 7 December at Chirinkotan (48.98 ° N, 153.48 ° E), in yellow aviation code
- between 2 and 5 December, at Chirpoi volcano (46.525 ° N, 150.875 ° E), in yellow aviation code
- on december 3 at Sinarka (48.875 ° N, 154 175 ° E), accompanied by a diffuse plume of steam, gas and some ash drifting NE 40 km, as well as diffuse emission of gases and steam on 6 December. His aviation code is yellow.

The GVP report  vapor and gas emissions at Sinarka since November 11, 2014.

The Sinarka volcano on the island Shiashkotan, north of the Kuril Islands - photo Imgg.ru / 2007-2008

The Sinarka volcano on the island Shiashkotan, north of the Kuril Islands - photo Imgg.ru / 2007-2008

 The Sinarka - photo Alexander Belousov

The Sinarka - photo Alexander Belousov

The Kuril Islands form a volcanic archipelago, a broken line of 1,250 km from the southern tip of Kamchatka at the northern tip of Hokkaido, in Japan, which geographically separates the Sea of Okhotsk from the Pacific Ocean.

Kuril includes 68 volcanic centers above the sea level, including 36 considered as active recently, and many submarine volcanoes. These remote islands, mostly uninhabited, are located a few hundred kilometers of major air corridors used daily by more than 200 aircraft, which warrants vigilance.

Location of different volcanoes in the Kuril archipelago and local tectonics: the Pacific plate dives under the microplate Okhotsk - SWC: Soya warm current; KC: Kamchatka Current. - Doc. A.Belousov / Institute of Volcanology and Seismology, Petropavlovsk, Russia & T.Miller / USGS

Location of different volcanoes in the Kuril archipelago and local tectonics: the Pacific plate dives under the microplate Okhotsk - SWC: Soya warm current; KC: Kamchatka Current. - Doc. A.Belousov / Institute of Volcanology and Seismology, Petropavlovsk, Russia & T.Miller / USGS

The Sinarka (in Russian. Влк Синарка; in Japanese: 黒 岳; Kurodake) is a stratovolcano that occupies the north of the island Shiashkotan, separated from Kuntomintar Volcano, located on the south, by a narrow isthmus.

It has erupted four times between 1725 and 1878.

Its last major eruption began in 1872 and ended in 1878. Of VEI 4, it produced pyroclastic flows, some of which are responsible for the destruction of the village of Ainu. After the eruption, a significant andesitic lava dome filled the post-glacial andesitic cone set in a depression open towards the north-west ; two other domes are close to the edges of the caldera.
 

The Shiashkotan island with the Sinarka volcano, northeast, and southwest, the Kuntomintar volcano - Landsat image.

The Shiashkotan island with the Sinarka volcano, northeast, and southwest, the Kuntomintar volcano - Landsat image.

Sources :

- Global Volcanism Program - weekly reports

- Global Volcanism Program - Sinarka ; Chirpoi ; Chirinkotan

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The 100 days of the Icelandic eruption at Holuhraun just been celebrated by the Icelandic Met Office staff.

100 days Holuhraun festivals in IMO - cakes are successful and smiles are at the measure of harvested scientific results - photo IES / Twitter

100 days Holuhraun festivals in IMO - cakes are successful and smiles are at the measure of harvested scientific results - photo IES / Twitter

Eruption of Holuhraun - photo lukas-gawenda.de / pic.twitter.com-WairVbpIki / 12.09.2014

Eruption of Holuhraun - photo lukas-gawenda.de / pic.twitter.com-WairVbpIki / 12.09.2014

The fissure eruption began on August 31, 2014; it is characterized by an importantcontinuous and stable emission of lava. The petrological analysis of the magma shows a primitive basalt, of  chemical composition typic of the Bárðarbunga's volcanic system. It also suggests that this type of magma has stabilized between 9 and 20 km deep, which means he has not resided in the shallow crust.

From an initial crack of 1500 meters, the lava has spread to form a vast lava field that reaches on 5 December a surface of 76.2 km² ... and the eruption can still continue for months.

 

The lava field of the Holouhraun 12/08/2014 - photo Air Iceland

The lava field of the Holouhraun 12/08/2014 - photo Air Iceland

To the left, extent of the lava field, 05/12/2014 - Doc. IES - to the right, changing of the lava field during the 100 days (29.08 - 14.11) - Doc. based on SLAR imagery from the Icelandic Coast Guard. Coordinates and outlines: Icelandic Meteorological Office - click to enlarge ..To the left, extent of the lava field, 05/12/2014 - Doc. IES - to the right, changing of the lava field during the 100 days (29.08 - 14.11) - Doc. based on SLAR imagery from the Icelandic Coast Guard. Coordinates and outlines: Icelandic Meteorological Office - click to enlarge ..

To the left, extent of the lava field, 05/12/2014 - Doc. IES - to the right, changing of the lava field during the 100 days (29.08 - 14.11) - Doc. based on SLAR imagery from the Icelandic Coast Guard. Coordinates and outlines: Icelandic Meteorological Office - click to enlarge ..

The new lava field is the most extensive ever seen in Iceland since the eruption of Laki in 1783-1784, and probably the third largest on Earth since this date.

But everything is relative ... with some supporting figures.
- Eruption 2014 Holuhraun: duration over 100 days, still ongoing -  emitted volume of lava : < 2 km³ - extension to 12/05/2014: 76.2 km²
- Laki eruption in 1783-1784: Duration: 8 months - lava emitted volume: 14.7 cubic kilometers - lava field 565 km²
- Eruption of Eldgjá in 934: Duration: about six years - issued volume of lava: 18.3 km³.- lava field: 781 km².

Either at a constant rate, a ratio of 1.83 km³ / month for Laki, 0.66 km³ / month for Holuhraun, and 0.25 km³ / month for Eldgjá.

Comparison of surfaces covered by lava eruptions of Holuhraun, Laki and Eldgjá - doc IMO / IES / Natural Hzards group - References: Eldgjá and outlines Laki and Eldgjá volume from Thordarson et al. 2001. Volume of Laki from Thordarson et al. 1993. Nornahraun data from the University of Iceland, Institute of Earth Sciences' Volcanology and Natural Hazards Group. Specialist William Moreland.

Comparison of surfaces covered by lava eruptions of Holuhraun, Laki and Eldgjá - doc IMO / IES / Natural Hzards group - References: Eldgjá and outlines Laki and Eldgjá volume from Thordarson et al. 2001. Volume of Laki from Thordarson et al. 1993. Nornahraun data from the University of Iceland, Institute of Earth Sciences' Volcanology and Natural Hazards Group. Specialist William Moreland.

The amount of gas emitted by the eruption of Holuhraun is important, and we must go back 150 years back to find an event with a comparable impact on health and environment : Trölladyngja.

Since that time, the gas monotoring has improved. The IMO has used the FTIR and DOAS instruments to estimate the flux of SO2, and other components of the volcanic cloud, in which the present gases are mainly SO2, CO2, hydrochloric and hydrofluoric acid, and vapor water.

A wide range is coming out this mesurements, with respect to a constant emission of gas to date, between 3.5 Mt and 11.2 Mt, respectively considering the average flow and the emission peak.

Compared with the eruption of Laki, the latter issued between 5 to 15 times more gas than the eruption of Holuhraun (122 Mt of SO2 in 8 months, or about 51 Mt in 100 days, at constant flow)
 

Gases emitted by the eruption of Holuhraun - Ragnar Axelsson Photo (RAX) 09/12/2014 - Iceland Review.

Gases emitted by the eruption of Holuhraun - Ragnar Axelsson Photo (RAX) 09/12/2014 - Iceland Review.

It is also the first time that we can see the long term effects on human and animal health of that air pollution by volcanic gas emissions.

Another problem is emerging : the pollution generated by the eruption causes acid rain, and in the Icelandic winter, acid snow which accumulate
in the highlands. Scientists fear that the acidity levels of lakes and rivers will greatly increase with the melting of the snow in the spring, and do alter the vegetation and the ecology of drained areas ... measures should be taken as soon as the snow begins to melt in 2015.

The beauty of the phenomenon should not obscure the effects on health and the environment - photo Ragnar Axelsson (RAX) - Iceland Review.

The beauty of the phenomenon should not obscure the effects on health and the environment - photo Ragnar Axelsson (RAX) - Iceland Review.

Sources :

- Icelandic Met Office

- University of Iceland

- Iceland Review

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