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Earth of fire

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

actualites volcaniques

Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

The alert level of Gunung Slamet has been raised to Siaga / 3, August 12, 2014, by the VSI, due to a significant increase in exhaled plume from the volcano since May, and observation of nocturnal glow.
 

Gunung Slamet - the 8/11/2014 - Photo Gunung Slamet Facebook

Gunung Slamet - the 8/11/2014 - Photo Gunung Slamet Facebook

In May, a nocturnal glow was observed 14 times, accompanied by outbreaks of ash amount from 150 to 1.500 m above the top. Between 15 and 30 June, 14 moderate ash eruptions amount between 500 and 1500 m above the summit .

An acceleration of emissions is observed on 1 and 2 July, with 17 moderate plumes. The alert level 2 is then held, and a 2 km radius
prohibited area around the crater is introduced.

On July 15, the Darwin VAAC Informs, based on satellite images a plume climbing to 4500 meters above sea level, about 1,100 m above the summit, before drifting about 83 km to the west and the north.

The raising of the alert level occurs when many fans were planning to climb the volcano slopes to celebrate the 69 th anniversary of Independence. We must remember that the last eruption of Gunung Slamet confirmed by the GVP date period 8 March 2014. May 6, 2014 (VEI 2) - see photo below.

 Activity parameters of Slamet between 1 January and 11 August, 2014 - graphic VSI Badan Geologi

Activity parameters of Slamet between 1 January and 11 August, 2014 - graphic VSI Badan Geologi

Gunung Slamet is located in the center of the island of Java, and consists of two overlaping buildings, a former basalto-andesitic to andesitic volcano to the west, and a younger basaltic to basalto- andesitic volcano,to the east. Three dozen of cinder cones are dotting its low slopes, and only one on the western flank. Four craters are at the top of Slamet, with activity migrating over times to a site towards the SW. Historical eruptions originate, from the 18th century, from a crater on the west side of the summit, marked by explosions lasting only a few days to a few weeks.

Gunung Slamet - 14 March 2014 - photo Andi / Guide Volcanodiscovery

Gunung Slamet - 14 March 2014 - photo Andi / Guide Volcanodiscovery

Gunung Slamet - active crater - photo R. Woodall

Gunung Slamet - active crater - photo R. Woodall

Sources :

- Antara news

- VSI Badan Geologi - Peningkatan Tingkat Aktivitas G. Slamet Dari Waspada (level Ii) Ke Siaga (level III) - 12.08.2014 - link

- Global Volcanism Program  - Slamet

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

Following a high level of explosive activity at the NE and NO crater, and a strong degassing of the central crater of Stromboli, Emergency Preparedness has closed the access to the summit on August 5.

Between 9:13 and 17:23, on August 5, deformation of the outer flanks of the northeast crater has been detected ... the location is important for the following events.

 

Stromboli - lava flow 06/08/2014 - photo Dolcevitagroup / pic.twitter.com-SfOpQ2w7gl

Stromboli - lava flow 06/08/2014 - photo Dolcevitagroup / pic.twitter.com-SfOpQ2w7gl

On August 6, a new lava flow began with an overflow between the N1 and N2 vents / crater northeast. The beginning of the lava flow coincides with collapses between 2:06 p.m. and  2:51 p.m.. The emission of lava is made in several successive castings, who joined the coast line. The effusive activity continued overnight juqu'aux early hours on August 7.
 

   Stromboli -  seismicity, between 4am and 7am loc. , with an increase to 5:15 - Doc INGV

Stromboli - seismicity, between 4am and 7am loc. , with an increase to 5:15 - Doc INGV

On August 7, a significant collapse accompanied the opening of a new effusive mouth, to 5h 18, at the northern base of the NE crater. A rising tremor confirmed the schedule (see above).

Stromboli - thermal anomaly from 5:30 am to 5:36 loc - doc Webcam therm. INGV / via VolcanodiscoveryStromboli - thermal anomaly from 5:30 am to 5:36 loc - doc Webcam therm. INGV / via Volcanodiscovery

Stromboli - thermal anomaly from 5:30 am to 5:36 loc - doc Webcam therm. INGV / via Volcanodiscovery

Stromboli - 07.08.2014 / 6:23 local - three lava streams enter the sea and others will get there - Doc. INGV Catania - camera SCT

Stromboli - 07.08.2014 / 6:23 local - three lava streams enter the sea and others will get there - Doc. INGV Catania - camera SCT

A large thermal anomaly marked the slope at the base of the NE crater, indicating a new flood of lava. It had to cross the ledge, created in 2002-2003, which separates the cone northern from the rim of Sciara del Fuoco, then plunged into the sea.

The effusion ratio is high, and much higher than those characterizing the overflows of previous years; in a short time, the flow is separated into various arms of lava, accompanied by landslides. The arrival of the flow at sea generated significant plumes of steam.
The thermal anomaly was still clearly visible on the local thermal webcam 16h.

Stromboli - Time-lapse video of the overflow of August 6 and 7 - Doc. Volcanodiscovery

Stromboli - lava flow and blocks reaching the sea by the Sciara del Fuoco, 08/07/2014 - photo Mike Schuler

Stromboli - lava flow and blocks reaching the sea by the Sciara del Fuoco, 08/07/2014 - photo Mike Schuler

Stromboli - 07/08/2014 - lots of lava entries in the sea generate steam plumes - photo website Meteoweb

Stromboli - 07/08/2014 - lots of lava entries in the sea generate steam plumes - photo website Meteoweb

Stromboli - thermal anomaly at 6:36 a.m and 1:48 p.m. - Doc. webcam therm. INGVStromboli - thermal anomaly at 6:36 a.m and 1:48 p.m. - Doc. webcam therm. INGV

Stromboli - thermal anomaly at 6:36 a.m and 1:48 p.m. - Doc. webcam therm. INGV

Sources :

- INGV Catania

- Volcanodiscovery news

- You reporter.it

 

To Etnathe eruption of subterminal type that marks the NE crater continues a month after its beginning.

Boris Behncke describes the activity during a field visit on August 6: it varies between powerful Strombolian explosions, the "flashing arcs" ,and "almost silent" ash and bombs emissions
.

 

Etna - explosion to the Northeast crater 06/08/2014 - photo EtnaWalk

Etna - explosion to the Northeast crater 06/08/2014 - photo EtnaWalk

 Etna - lava flow from the activity at the NEC 08/06/2014 - photo Boris Behncke

Etna - lava flow from the activity at the NEC 08/06/2014 - photo Boris Behncke

.  Etna - smoke ring on 08/06/2014 - photo turi Caggegi / iEtna

. Etna - smoke ring on 08/06/2014 - photo turi Caggegi / iEtna

Sources :

- Boris Behncke / Facebook & You Tube

- EtnaWalk / Facebook

- Turi Caggegi / iEtna

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

In 1969, it was noted for the first time volcanoes on Io, a satellite of Jupiter. Ground-based telescopes have shown subsequently that eruptions and lava fountains were common, but important eruptions were much rarer.

Io is the planet / the moon the most active  on a volcanological level of our solar system. It is also the only celestial body which his volcanoes emit an extremely hot lava, similar to the one we saw on earth. Due to the low gravity prevailing on Io, these large volcanic eruptions produce an umbrella debris that flow in space.

An eruption on Io - doc. NASA 05.2011

An eruption on Io - doc. NASA 05.2011

In August 2013, three massive volcanic eruptions marked this satellite of Jupiter, in a fifteen days ... leading to the hypothesis that these phenomena considered as rare, are actually much more common than previously thought.

A study made ​​by Imke de Pater and his team from the Californian University of  Berkeley, reveals that these three eruptions, including the last of the series, the more energetic, are likely characterized by "curtain of fire", and fissural emission of lava ... on more than 20 km.

Images of Io obtained at different infrared wavelengths (in microns, μm, or millionths of a meter) with the W. M. Keck Observatory’s 10-meter Keck II telescope on Aug. 15, 2013 (a-c) and the Gemini North telescope on Aug. 29, 2013 (d). The bar on the right of each image indicates the intensity of the infrared emission. Note that emissions from the large volcanic outbursts on Aug. 15 at Rarog and Heno Paterae have substantially faded by Aug. 29. A second bright spot is visible to the north of the Rarog and Heno eruptions in c and to the west of the outburst in d. This hot spot was identified as Loki Patera, a lava lake that appeared to be particularly active at the same time. Image by Imke de Pater and Katherine de Kleer, UC Berkeley.

Images of Io obtained at different infrared wavelengths (in microns, μm, or millionths of a meter) with the W. M. Keck Observatory’s 10-meter Keck II telescope on Aug. 15, 2013 (a-c) and the Gemini North telescope on Aug. 29, 2013 (d). The bar on the right of each image indicates the intensity of the infrared emission. Note that emissions from the large volcanic outbursts on Aug. 15 at Rarog and Heno Paterae have substantially faded by Aug. 29. A second bright spot is visible to the north of the Rarog and Heno eruptions in c and to the west of the outburst in d. This hot spot was identified as Loki Patera, a lava lake that appeared to be particularly active at the same time. Image by Imke de Pater and Katherine de Kleer, UC Berkeley.

The first two eruptions discovered by Pater, through an infra-red camera coupled to a telescope of the Keck Observatory in Hawaii, concern the southern hemisphere of Io One, in the caldera named Rarog patera, produced a thick casting over 80 km ², and the other near Heno patera, gave flows covering more than 190 km ².

 

 

 

The Aug. 29, 2013, outburst on Io was among the largest ever observed on the most volcanically active body in the solar system. Infrared image taken by Gemini North telescope, courtesy of Katherine de Kleer, UC Berkeley.

The Aug. 29, 2013, outburst on Io was among the largest ever observed on the most volcanically active body in the solar system. Infrared image taken by Gemini North telescope, courtesy of Katherine de Kleer, UC Berkeley.

The third eruption, much larger, took place August 29, 2013. It was discovered through the instruments (Gemini and IRTF) located on Mauna Kea. The temperatures recorded during the eruption are much higher than those recorded during the current terrestrial eruptions, indicating that magma composition has encountered on Earth only in the formative years of our planet. The emitted energy is about 20 terawatts, and the volume of lava expelled from several cubic kilometers.

These eruptions observed on Io will help to understand how the great plains of lava are established on Earth, and the complete history of ancient eruptions on our planet
.

 

Sources :

- U.C. Berkeley news center – A hellacious two weeks on Jupiter’s moon Io – link

- Science Codex  - extreme volcanism : image captures one of the brighest volcanoes in the solar system - link

- Hawaii Tribune Herals  - Hawaii telescopes capture volcanic eruption on Io

 

 

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Piton de la Fournaise - installation of sensors of the VolcArray project in june - photo IS Terre.

Piton de la Fournaise - installation of sensors of the VolcArray project in june - photo IS Terre.

The project "VolcArray" , coordinated by researchers from the Institute of Earth Sciences of Grenoble / France (IS Terre), under the direction of Florent Brenguier, in collaboration with the Volcanological Observatory of Piton de la Fournaise / La Réunion, aims to probe the active heart of the volcano, through temporary deployment of 300 sensors on the massif de la Fournaise.
  Piton de La Fournaise - routing the sensors - photo Eric Larose / IS Earth

Piton de La Fournaise - routing the sensors - photo Eric Larose / IS Earth

Piton de la Fournaise -  the motivated team in the rain and fog - photo photo Eric Larose / IS Terre 12/07/2014

Piton de la Fournaise - the motivated team in the rain and fog - photo photo Eric Larose / IS Terre 12/07/2014

Piton de La Fournaise - sensor deployment under difficult conditions in July - photo Eric Larose / IS Terre

Piton de La Fournaise - sensor deployment under difficult conditions in July - photo Eric Larose / IS Terre

This large number of high-tech sensors, each weighing 2.5 kg, usually used in the petroleum industry for hydrocarbon exploration (Fairfield Company / Houston), was installed on three square antennas, tours towards the inside of the volcano, during the months of June and July 2014, sometimes under difficult conditions.

They will record for one month the seismic noise and try to visualize an area 3,000 meters below the volcano, just above sea level and that may contain lava. Seven hundred and fifty pounds of materials were transported through the air, but also on men's backs, when air transport conditions were not met.

Piton de La Fournaise - Phase 4; storage of the sensors for repatriation - photo Eric Larose / IS Terre

Piton de La Fournaise - Phase 4; storage of the sensors for repatriation - photo Eric Larose / IS Terre

Piton de La Fournaise - Phase 4: repatriation of sensors by helicopter - photo Eric Larose / IS Terre

Piton de La Fournaise - Phase 4: repatriation of sensors by helicopter - photo Eric Larose / IS Terre

The phase 4 of the project VolcArray just ended with the uninstallation of the sensors and the repatriation by helicopter to the laboratory, at the very end of July. This will also allow dismantling of obsolete installations ... and evacuate waste.

 

 

The analysis and compilation of results phase is underway.

To be continued !

 

Sources :

- IS Terre Grenoble - link

- Musée de La Réunion - VolcArray : le piton de la fournaise sous la loupe - link

- INSU / CNRS - L'analyse du bruit sismique pourrait servir à la localisation des futures éruptions volcaniques -  link

- Journal of geophysical research - Imaging preeruptive and coeruptive structural and mechanical changes of a volcano with ambient seismic noise A; Obermann & al. 12.2013- link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

There are enough similarities between Mars and the King's Bowl volcanic field for NASA invested $ 500,000 with Idaho State University / ISU for further study of the area using GPS working across centimeter.

The volcanologist Shannon Kobs-Nawotniak and his team focus on King's Bowl and topography micro-scale: an extensive volcanic activity marked the Great Rift Valley and the area of ​​Crater of the Moon / Wapi volcanic field when the hot spot of Yellowstone was under the crust in this area before the north American plate moves farther west.

The route of the Great Rift Valley in Idaho and the site of King's Bowl / King's Bowl lava field, cutting the rift - photo Susan Sakimoto in GVP (NASA, courtesy of Scott Hughes, Idaho State University).

The route of the Great Rift Valley in Idaho and the site of King's Bowl / King's Bowl lava field, cutting the rift - photo Susan Sakimoto in GVP (NASA, courtesy of Scott Hughes, Idaho State University).

Left, location of the site of King's Bowl - right, igneous structures of southeastern Idaho, with King's Bowl lava field - doc.Kuntz et al, 1982 / in Digital Geology of Idaho - A click to enlarge.Left, location of the site of King's Bowl - right, igneous structures of southeastern Idaho, with King's Bowl lava field - doc.Kuntz et al, 1982 / in Digital Geology of Idaho - A click to enlarge.

Left, location of the site of King's Bowl - right, igneous structures of southeastern Idaho, with King's Bowl lava field - doc.Kuntz et al, 1982 / in Digital Geology of Idaho - A click to enlarge.

The study aims area of King's Bowl, north of the volcanic field Wapi, formed by rising magma, there 2130 years, along a basaltic dyke and a phreatic explosion that created the explosion crater, 80 meters long wide and 30 meters deep.

It aims to use new measures to better understand the changes in texture caused by the eruption and how water interacted to cause the explosion.

King's Bowl / Idaho - photo Oregonstate

King's Bowl / Idaho - photo Oregonstate

 King's Bowl / Idaho - an eye in the explosion crater - photo Caedus328 / Panoramio

King's Bowl / Idaho - an eye in the explosion crater - photo Caedus328 / Panoramio

King's Bowl - scheme of alimentation by feeder-dike and rift with the two types of cracks - Scheme in Thruitt thesis

King's Bowl - scheme of alimentation by feeder-dike and rift with the two types of cracks - Scheme in Thruitt thesis

To feed their database, researchers will examine vesiculation, the degree of bubbling that occurred in samples (some lava blocks with a size of 40 meters), to get an idea of all the set.

Techniques and equipment used by the ISU in the study are connected with the FINESSE project of NASA. FINESSE, for Fast Infrared Exoplanet Spectroscopy Survey Explorer, is devoted to understanding the formation, evolution, and architectures of exoplanetary systems.

Fieldwork completed, the data will be analyzed by supercomputers of the IUS and the results presented 
in December at the conference of AGU / American Geological Union in San Francisco.
 

King's Bowl / Idaho - photo Crater of the Moon Shoshone Field Office USRD

King's Bowl / Idaho - photo Crater of the Moon Shoshone Field Office USRD

Sources :

- Komo news - Mars secrets unlocked at Craters of the Moon monument – link

- Global Volcanism Program – Wapi lava field

- Digital Geology of Idaho - Neogene Snake River Plain-Yellowstone Volcanic Province – link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

The villagers of Telina in the Marovo Lagoon in the Solomon Islands, live in fear of their paradise invaded by debris from an eruption of the submarine volcano Kavachi.

Solomon Islands - Marovo Lagoon - photo Magnificent destination Besttourism

Solomon Islands - Marovo Lagoon - photo Magnificent destination Besttourism

Solomon Islands - the island Vangunu and lagoon Marovo - doc. Nasa

Solomon Islands - the island Vangunu and lagoon Marovo - doc. Nasa

The Global Volcanism Program reports that a NASA satellite spotted on 29 January 2014 a plume of discolored water to eastern side of Kavachi, probably formed by dissolved gases and lava fragments.

Last month, disorders and swirling waters indicating the location of the seamount were noticed, and some fragments from the volcano were stranded on islands in the lagoon ... these signs are increasing local fears to see the activity travel to this area.

The villagers asked the authorities, yet minimize the events, to visit Marovo and investigate the situation.

 

Kavachy eruption in April 2007 - photo Today Images

Kavachy eruption in April 2007 - photo Today Images

Kavachi - January 2014 eruption - doc. NASA EO-1 Ali 29/01/2014

Kavachi - January 2014 eruption - doc. NASA EO-1 Ali 29/01/2014

The Seamont Kavachi, also called " Rejo te Kvachi " / " Kavachi's oven ", is located south of the Vangunu island, only 30 km. north of the site of the subduction of the Indo-Australian plate beneath the Pacific plate.

This submarine basaltic to andesitic volcano has produced since its first recorded eruption in 1939, during different subaerial eruptions and
phreatomagmatic explosions, no less than eight ephemeral islands.

In the 21st century, four eruptions were observed: 1999 to August 2003, March 2004, April 2007 and January 2014 (GVP)

The Australian CSIRO / Commonwealth Scientific and Industrial Research Organization described in 2000, and in 2002, a conical shape relief with a basal diameter of 8000 meters, rising to 1000-1200 m from the depths north and more south side . The summit of Kavachi is seen between 60 meters below the sea level and the surface, depending on the activity.

Left, map of Marovo lagoon - right, bathymetries of Kavachi Seamont - doc. CSIRO - GVP - a click to enlarge. Left, map of Marovo lagoon - right, bathymetries of Kavachi Seamont - doc. CSIRO - GVP - a click to enlarge.

Left, map of Marovo lagoon - right, bathymetries of Kavachi Seamont - doc. CSIRO - GVP - a click to enlarge.

Stay tuned ... the Kavachi being considered as one of  the submarine volcanoes among the most active in the southwest Pacific.

 

Sources :

- Solomon Star news – Villagers live in fear of volcano – link  

- Global Volcanism Program - Kavachi

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
Tungurahua - 01.08.2014 - photo OVT - IGEPN

Tungurahua - 01.08.2014 - photo OVT - IGEPN

Since July 28, the activity of Tungurahua is rising. On 29.08, the volcano emitted steadily  water vapor from the crater.
On 1 August, from 10 h30, three small plumes rising, moderately loaded in ash, two kilometers high ... followed at 14:50 local, by a significant release of ash, formed a plume 4,000 meters before heading to ONO.
SO2 emissions are rising, with 30 and 31 July  respectively 2966 tonnes / day and 1963 t / d , in relation to the presence of fresh magma in the upper volcano conduits.

The level of seismicity is up too, with tremor for two days and on 1 August, a volcano-tectonic earthquake of magnitude1, 9 to a depth of 5 km. ,presumably related to fracturation of rock.


The OVT indicates a high probability of a large explosion in the short term, probably accompanied by pyroclastic flows in drainage, up to inhabited areas and significant ash falls.

Tungurahua - 01.08.2014 / 18h40 - photo Jose Luis Espinosa Naranjo

Tungurahua - 01.08.2014 / 18h40 - photo Jose Luis Espinosa Naranjo

Tungurahua - 01.08.2014 - webcam IGEPN

Tungurahua - 01.08.2014 - webcam IGEPN

Source : IGEPN - special information 01.08.2014

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

Enceladus, a moon of the planet Saturn, was inspected in 2004 by the Cassini spacecraft.

Since, the fact that Enceladus expels water in space is not a surprise ... but where does this water come from ?  from water just beneath the surface or from water deep-seated ?

 

Enceladus - a survey in 2009 by Cassini revealed plumes of water vapor and ice along the "tiger stripes" near the south pole located.

Enceladus - a survey in 2009 by Cassini revealed plumes of water vapor and ice along the "tiger stripes" near the south pole located.

Left, a view artist of the penetration of Cassini in the plumes of Enceladus - right , comparison in size between Enceladus, moon and our Earth - Doc. NASA JPL - Caltech - SSI. - A click for a full view. Left, a view artist of the penetration of Cassini in the plumes of Enceladus - right , comparison in size between Enceladus, moon and our Earth - Doc. NASA JPL - Caltech - SSI. - A click for a full view.

Left, a view artist of the penetration of Cassini in the plumes of Enceladus - right , comparison in size between Enceladus, moon and our Earth - Doc. NASA JPL - Caltech - SSI. - A click for a full view.

Geysers basin of Enceladus, 3D modeling - doc. in C. Porco & al.2014 / Astronomical Journal / NASA / JPL-Caltech / Space Science Institute

Geysers basin of Enceladus, 3D modeling - doc. in C. Porco & al.2014 / Astronomical Journal / NASA / JPL-Caltech / Space Science Institute

Cassini approached in 2009 the plumes emitted from Enceladus and its instruments have enabled a discovery : water emitted is salty. This feature highlights a source of water from a depth sufficient to have had prolonged the contact with the mineral constituents that satellite.

Recently, measurements of subtle variations in the gravity field of Enceladus suggest the presence of an ocean located 48 km beneath a thick layer of ice. The study team of Carolyn Porco, published in March 2014 in The Astronomical Journal, presents an analysis of geysering, tidal stresses and abnormal thermal emission from the region of the south pole of Enceladus, where a hundred geysers in eruption are located on four major fractures intersecting the region.

Cut in the ice sheet of  Enceladus above a fracture and active geysers, illustrating the physical and thermal structure and processes under and on the surface of the satellite. - Doc. NASA / JPL-Caltech / Space Science Institute

Cut in the ice sheet of Enceladus above a fracture and active geysers, illustrating the physical and thermal structure and processes under and on the surface of the satellite. - Doc. NASA / JPL-Caltech / Space Science Institute

Fractures are known as " tiger stripes ". About three or four geysers, locations come from hotspots located just a few meters off.

According Carolyn Porco: "They are not phenomena close to the surface ... This indicates that the only possible source of the geysers is in the underlying sea. We believe that the fractures plunge depth.."

 

Enceladus - view along the fractures at the south pole, expelling geysers of water and ice - Photo NASA / JPL-Caltech / Space Science Institute.
Enceladus - view along the fractures at the south pole, expelling geysers of water and ice - Photo NASA / JPL-Caltech / Space Science Institute.

Enceladus - view along the fractures at the south pole, expelling geysers of water and ice - Photo NASA / JPL-Caltech / Space Science Institute.

Sources :

- CICLOPS – Cassini Imaging Central Laboratory Operations - link 

- IOP Science - How the Geysers, Tidal Stresses, and Thermal Emission across the South Polar Terrain of Enceladus are Related  - Carolyn Porco et al. 2014 The Astronomical Journal 148 45 - link

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
The "plumbing" system of Volcanoes of Washington are the subject of scientific studies by geophysicists.

" Volcanoes of the Cascades threaten urban centers from Vancouver to Portland, and we would understand their internal operations to better predict when they will erupt and the importance of these eruptions ..." says Alan Levander, of Rice University in Houston.
 

Mt Rainier overlooking the city of Tacoma

Mt Rainier overlooking the city of Tacoma

This week, the scientists will drill 23 locations on Mount St Helens in order to detonate charges, simulating an earthquake of M2, and thus study the internal plumbing of the volcano through the seismic network (3,500 new seismic sensors placed around the volcano).
 

St Helens - placement of seismometers in June - photo Houston Chronicles

St Helens - placement of seismometers in June - photo Houston Chronicles

St Helens plumbing System - Doc. Dzurisin 2012 / CVO-USGS

St Helens plumbing System - Doc. Dzurisin 2012 / CVO-USGS

The Journal Nature publishes this week a study on the internal plumbing of Mt Rainier, using seismic measurements (data collected in 2008-2009), electrical resistance and magnetotelluric measurements (data collected in 2009-2010).

The image shows the feed paths of the magma chamber beneath the volcano by total or partial melting rocks. The rocks start to fuse at about 80 km. under the volcano, and fall to one hand to the east and deep diving with the subducting plate, to another to the surface in the direction of the magma chamber, a little west of Rainier. (Picture may show a lobe of the magma chamber extending to the NW, due to the northern position of the sensors used in this study).

The movement of magma towards the surface is estimated to be 0.4 inches / 10.16 mm. per year. It is estimated that about 30% of the magma chamber, located 8 km. under the volcano, consists of molten rock .... The dimensions of the magma chamber: EO extension of 8-16 km, and the same in thickness (under reserve subject, because the NS dimension could not be determined by the position of the sensors).

Top image: Mt Rainier and supply plumbing system beneath the volcano (symbolized by a red triangle) - the Juan de Fuca plate subducting in blue - Orange-yellow areas correspond to a higher electrical conductivity (or less resistance .) and report the position of fluids and partial melting rocks - red oval mark the hypocenters of earthquakes - bottom image: position of magnetotelluric sensors in pink / purple and seismic stations in yellow / Photo Credit: Shane McGary R, Woods Hole Oceanographic Institution - a click to enlarge.
Top image: Mt Rainier and supply plumbing system beneath the volcano (symbolized by a red triangle) - the Juan de Fuca plate subducting in blue - Orange-yellow areas correspond to a higher electrical conductivity (or less resistance .) and report the position of fluids and partial melting rocks - red oval mark the hypocenters of earthquakes - bottom image: position of magnetotelluric sensors in pink / purple and seismic stations in yellow / Photo Credit: Shane McGary R, Woods Hole Oceanographic Institution - a click to enlarge.

Top image: Mt Rainier and supply plumbing system beneath the volcano (symbolized by a red triangle) - the Juan de Fuca plate subducting in blue - Orange-yellow areas correspond to a higher electrical conductivity (or less resistance .) and report the position of fluids and partial melting rocks - red oval mark the hypocenters of earthquakes - bottom image: position of magnetotelluric sensors in pink / purple and seismic stations in yellow / Photo Credit: Shane McGary R, Woods Hole Oceanographic Institution - a click to enlarge.

Areas affected by mudflows from Mt Rainier in the past 5,600 years - Doc. CVO / USGS

Areas affected by mudflows from Mt Rainier in the past 5,600 years - Doc. CVO / USGS

Sources :

- New View of Rainier’s Volcanic Plumbing  / University of Utah News - link

- AP / Presse locale - Scientists use new techniques to predict volcano eruptions - link

- SSA 2014 Meeting – Evidence for ongoing magma recharge at Mt St Helens - CVO

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Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques

A recent image of the Yellowstone magma chamber has been published by the Volcano Observatory, following measures of seismic tomography carried out by seismologists from the University of Utah and the Swiss Federal Institute of Technology.

 


The resulting model reveals a large area where P-waves travel more slowly, and interpreted as resulting from the presence of partially molten hot rocks ... the magma chamber is 90 km. length is between 5 and 17 km. deep, and is 2.5 times greater that thinking in the previous study.

This "growth" is due to an extension of the coverage by the seismograph network in the NE of the Park.

Schematic cross under the Yellowstone / Snake river plain, oriented SW-NE, describing the Yellowstone magma chamber, the rise of magma from the mantle, the move of the tectonic plate above the mantle plume - doc.Farrell et al. / YVO / journal Geophysical Research Letters

Schematic cross under the Yellowstone / Snake river plain, oriented SW-NE, describing the Yellowstone magma chamber, the rise of magma from the mantle, the move of the tectonic plate above the mantle plume - doc.Farrell et al. / YVO / journal Geophysical Research Letters

The low velocity zone extends up to 15 km. northeast of the Yellowstone caldera at a depth of less than 5 km. It is to be linked with the presence of high temperature fluids (gases, hot water, and other fluids) as indicated by the gravity measurements.

The magma chamber contains 5 to 15% of molten rock, occupying the spaces between the solid / crystalline materials ... we are far from the 50% of molten rock necessary for an eruption.

Progress towards the NE of the magmatic system corresponds to the movement of the North American plate to the west, above the stationary mantle plume (Yellowstone hot spot), located at a depth of 60-90 km.

The Yellowstone Volcano Observatory says, if need be, that these details on the size of the magma chamber in no way reflect an increase of volcanic risk.

 

Firehole Lake Drive closed due to high temperature of the basement - Photo Yellowstone National Park

Firehole Lake Drive closed due to high temperature of the basement - Photo Yellowstone National Park

Similarly, closing on July 10 of Firehole Lake Drive, a one-way road that passes through Great Fountain Geyser, White Dome Geyser and Firehole lake, by road safety measures and maintenance after melting the asphalt overlay, should not announce any disaster.

Changes in temperature of the hydrothermal system regularly damage the road surface and the boardwalk, although this event is disruptive in the tourist season.


 

Map of Firehole Lake Drive - YNP

Map of Firehole Lake Drive - YNP

For those who could not access ... White Dome Geyser during a storm in 2009 - photo © Bernard Duyck

For those who could not access ... White Dome Geyser during a storm in 2009 - photo © Bernard Duyck

Firehole lake, still under the storm - photo © Bernard Duyck 2009.

Firehole lake, still under the storm - photo © Bernard Duyck 2009.

Sources :

- YVO - Yellowstone VolcanoObservatory - Using Seismic Waves to Image the Yellowstone Magma Storage Region - link

- MSN News - Hot spot: Yellowstone road melts, closing sites - link

- Huffington Post  - Yellowstone Road Melts, Shutting Down Access To Famous Geysers - link

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