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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
 Manam - the eruptive plume of 08.12.2018 seen tunes - ex. Brian Malone video

Manam - the eruptive plume of 08.12.2018 seen tunes - ex. Brian Malone video

Manam - 08.12.2018 photo taken from a ship of U.S. Navy via Jhay Mawengu / Facebook

Manam - 08.12.2018 photo taken from a ship of U.S. Navy via Jhay Mawengu / Facebook

A phase of explosive activity began December 8 at 13h local / 03h UTC at Manam volcano in Papua New Guinea.

The ash and gas plume rose more than 13.5 km, drifting east and northeast. Strong ashfall on the island is reported by observers (planes and US Navy ship), blocking the sun's rays and hiding the volcano's summit.

According to VAAC Darwin, the plume should dissipate within three hours.

Manam - 08.12.2018 - photo Scott Waide / Twitter

Manam - 08.12.2018 - photo Scott Waide / Twitter

Manam - 08.12.2018 - bulletin and Volcanic ash advisory of VAAC Darwin, respectively at 09hZ and 13h20Z - one click to enlargeManam - 08.12.2018 - bulletin and Volcanic ash advisory of VAAC Darwin, respectively at 09hZ and 13h20Z - one click to enlarge

Manam - 08.12.2018 - bulletin and Volcanic ash advisory of VAAC Darwin, respectively at 09hZ and 13h20Z - one click to enlarge

Manam 08.12.2018 - thermal anomalies at 3:45 pm - Doc Mirova_MODIS_VRP
Manam 08.12.2018 - thermal anomalies at 3:45 pm - Doc Mirova_MODIS_VRP

Manam 08.12.2018 - thermal anomalies at 3:45 pm - Doc Mirova_MODIS_VRP

Manam eruption 08.12.2018 / video Brian Malone

A previous eruptive phase dates from August 25, 2018. It was characterized by an eruptive plume at 15.2 km, and lava flows and pyroclastics in a valley NE of the island, which buried 6 houses (in GVP - link)

Sources: Madang Province news (via Shérine France), VAAC Darwin, Mirova, Scott Waide and Brian Malone / Twitter

Aqueous eruption of Steamboat geyser on 04.06.2018 - Photo by Jamie Farrell, University of Utah via USGS

Aqueous eruption of Steamboat geyser on 04.06.2018 - Photo by Jamie Farrell, University of Utah via USGS

The USGS reports the 30th water eruption 2018 of the Steamboat geyser, which is a record, at Yellowstone National Park this December 8 at 1:07 local.

These spectacular water eruptions do not imply a change in the volcanic activity of Yellowstone.

Source: USGS

Dukono - 08.12.2018 / 9h11WIT - photo Magma Indonesia

Dukono - 08.12.2018 / 9h11WIT - photo Magma Indonesia

An eruption occurred this December 8 at 9:12 local at Dukono volcano in the Moluccas. An ash plume developed to a height of 1529 meters asl. The eruption continues.

VAAC Darwin plans to ashes move west and then southwest.

An orange VONA has been issued and the activity level is 2 / waspada, with a 2 km radius ban around the Malupang Warirang crater. Ashes can fall on the island, a mask protection is recommended.

Source: PVMBG / Magma Indonesia
 

Dukono - Volcanic ash advisory at 09.12.2018 / 09h25 - Doc. VAAC Darwin IDY65290

Dukono - Volcanic ash advisory at 09.12.2018 / 09h25 - Doc. VAAC Darwin IDY65290

An eruption of Anak Krakatau on 9 December 2018 at 1050 WIB was accompanied by a column of ash observed at ± 700 m above the summit (± 1038 m above sea level). The column of ash is black and thick, leaning northward. This eruption is recorded on a seismogram of maximum amplitude of 57 mm and a duration of ± 5 minutes 29 seconds. Currently, G. Anak Krakatau is in Status Statute II (Waspada) with recommendations not to approach the crater within 2 km of the crater.

Source: PVMBG

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Publié le par Bernard Duyck
Publié dans : #volcanic activity

On December 7 at 3:13 local time, the Sernageomin recorded at the Nevados de Chillan complex an explosive event associated with an LP earthquake, in relation to the dynamics of internal fluids.

An incandescence, related to the emission of gas and pyroclasts at high temperature, was observed on webcams; the fallout remained close to the active crater.

This activity remains in the current orange alert standards, and maintained.

Nevados de Chillan - picture Sernageomin

Nevados de Chillan - picture Sernageomin

On the same day, between 13:05 and 13:40 local, the webcams of Planchón - Peteroa recorded an emission of particulate materials at a height of 1,300 meters, dispersing towards the ESE; the show was accompanied by tremor.

The complex remains on Amarilla technical volcanic alert ... other similar or more energetic episodes are likely to occur

Source: Sernageomin

Planchón - Peteroa - photo of the activity of 07.11.2018 / 17h / Sernageomin

Planchón - Peteroa - photo of the activity of 07.11.2018 / 17h / Sernageomin

At Popocatépetl, three explosions occurred on December 7th, at 6h43, 22h44 and 23h22 local respectively; they were accompanied by ash plumes at 1,800, 1,500 and 2,000 meters, and emissions of incandescent fragments on the flanks of the volcano.

The activity remains in the context of the Amarillo Fase 2 volcanic alert, and the observatory reminds the safety zone of 12 km to be respected, and the recommendations in case of falls of ashes.

Sources: Cenapred and Proteccion Civil Seguridad

Popocatépetl - explosions from 07.12.2018 to 6h47,22h45 and 23h23 respectively - images WebcamsdeMexico
Popocatépetl - explosions from 07.12.2018 to 6h47,22h45 and 23h23 respectively - images WebcamsdeMexico
Popocatépetl - explosions from 07.12.2018 to 6h47,22h45 and 23h23 respectively - images WebcamsdeMexico

Popocatépetl - explosions from 07.12.2018 to 6h47,22h45 and 23h23 respectively - images WebcamsdeMexico

An interesting development of volcanologists Boris Behncke and Marco Neri on the ongoing activity at the NSEC of Etna: it concerns the location of the small cone of slag, and the mouth at the origin of the lava flow and incandescent blocks, and fluctuations in activity.

Frequent changes in the direction mark the lava flows, which extend a few hundred meters east side of the NSEC, then stop. The magma takes two paths to the surface: one towards the cone of slag, seat of Strombolian activity, the other towards a mouth where accumulate viscous lava, which often have difficulty to sink and generate bearings of incandescent blocks. Both types of activity, explosive and effusive, show fluctuations.

Source: INGV Vulcani Wordpress Blog / 07,12,2018

Diagram of the theater of activity at the eastern mouth of the new crater southeast / made on the basis of photo taken on 05.12.2018 by Gianni Pennisi / via article INGV Vulcani Wordpress

Diagram of the theater of activity at the eastern mouth of the new crater southeast / made on the basis of photo taken on 05.12.2018 by Gianni Pennisi / via article INGV Vulcani Wordpress

Etna - strombolian activity from the cone of slag, and effusive from the oriental mouth - photo Gio Giusa 29.11.2018

Etna - strombolian activity from the cone of slag, and effusive from the oriental mouth - photo Gio Giusa 29.11.2018

The volcanological observatory of the Soufrière of Guadeloupe observes an increase in seismicity since the beginning of 2018. In the first part of the year this progression culminated with the very energetic crisis of the end of April. In addition, since 4 August 2018, the OVSG-IPGP has recorded a further marked increase in the number of earthquakes distributed in seismic swarms (total of 6 swarms with a peak of at least 50 earthquakes per day as of 31 October) of very low energy which succeed one another in a close manner in time. In October, a total of 1257 earthquakes of volcanic origin - 1,255 earthquakes VT and 2 LP - were recorded, located essentially between 500 and 1,500 m of depth under the summit. This increase of the seismicity recorded since August 4 is not therefore not directly related to this better resolution of the observation networks.

Soufrière of Guadeloupe - the Tarissan gouffre, which should be named after a vet who accidentally fell in it in the 19th century. - photo Stromboli on line

Soufrière of Guadeloupe - the Tarissan gouffre, which should be named after a vet who accidentally fell in it in the 19th century. - photo Stromboli on line

This recrudescence marks a change in the behavior of La Soufrière during the last months which involves other processes related to the circulation of fluids. An intensification of this trend could have implications for the phenomena that characterize the summit of Soufriere. Indeed, we can not exclude the possibility that the following phenomena occur suddenly and very localized: formation of geyser with projection of hot and acid mud, projections of ash and fragments over a few meters, sudden vaporization of liquid in overpressure , as well as the opening of new fumaroles.

The gaseous fumes in the vicinity and leeward of the main fumaroles of the summit (notably the Crater South, the Tarissan, and the Gouffre 1956) present, since 1998, proven risks of irritation and burns (eyes, skin, respiratory tracts) and hot and acid mud projections. Due to the presence of these toxic gases, a by-law of the city of Saint-Claude prohibits public access to certain areas of the summit.

The volcanic alert level remains alert / yellow.

Source: October monthly report of the volcanic activity of Soufriere Guadeloupe and regional seismicity.

Soufrière of Guadeloupe - the andesitic dome - photo Stromboli on line

Soufrière of Guadeloupe - the andesitic dome - photo Stromboli on line

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Etna - the "puttusiddu" of the NSEC seen from Milo - phot 06.12.2018 / 8h Boris Behncke

Etna - the "puttusiddu" of the NSEC seen from Milo - phot 06.12.2018 / 8h Boris Behncke

At Etna, three craters are still active this December 6, the Northeast, the Bocca Nuova and the new crater Southeast and its lava flow, marked by thermal anomalies reported by Mirova between 16 and 162 MW they days.

Sources: Sentinel 2, Boris Behncke and Gio Giusa

Etna 06.12.2018 - picture Sentinel2 nat colors

Etna 06.12.2018 - picture Sentinel2 nat colors

Etna 06.12.2018 - three craters present a thermal signal - images Sentinel2 Swir on the left, and bands 12,11,4 on the right - one click to enlargeEtna 06.12.2018 - three craters present a thermal signal - images Sentinel2 Swir on the left, and bands 12,11,4 on the right - one click to enlarge

Etna 06.12.2018 - three craters present a thermal signal - images Sentinel2 Swir on the left, and bands 12,11,4 on the right - one click to enlarge

Etna - thermal anomalies on 07.12.2018 - Doc.Mirova

Etna - thermal anomalies on 07.12.2018 - Doc.Mirova

The Sernageomin / OVDAS recorded on December 6 from 3:20pm a seismic swarm in Copahue; 200 volcano-tectonic earthquakes, associated with rock fracturing, occurred 6.2 km at the ENE of thecrater El Agrio.

The strongest earthquake, from ML 3.1, is recorded at 15:56 at a depth of 4,600 meters.

The superficial activity of the volcano is characterized as the days before by a plume of gas and fine particles at a height of about 800 meters.

The alert level remains in Amarillo.

Source: Sernageomin

Copahue seen from Caviahue on 01.12.2018 - Photo Valecaviahue

Copahue seen from Caviahue on 01.12.2018 - Photo Valecaviahue

At Popocatépetl, we notice, besides the exhalations, an explosion on December 6th at 1:17 pm; it was accompanied by a plume of gas, steam and ash that rose to 2,500 meters above the summit, before dispersing to the northwest.

Sources: Cenapred & Proteccion Civil Seguridad

Popocatépetl - the eruptive plume from 06.12.2018 to 13:25 - photos WebcamsdeMexico
Popocatépetl - the eruptive plume from 06.12.2018 to 13:25 - photos WebcamsdeMexico

Popocatépetl - the eruptive plume from 06.12.2018 to 13:25 - photos WebcamsdeMexico

The growth of the Merapi dome continues at the rate of 2,200 m³ per day, a little down between November 29 and yesterday. The summit dome reached the volume of 244,000 m³ on December 6th.

A thick whitish plume is observed 50 meters above the summit.

The seismicity of 06.12 is characterized by 52 eruption earthquakes, 14 emission earthquakes, 11 low frequency earthquakes and one hybrid earthquake.

The activity level remains at 2 / waspada

Source: PVMBG

Merapi - evolution of the dome between November 29 and December 6, 2018 - Doc. PVMBG

Merapi - evolution of the dome between November 29 and December 6, 2018 - Doc. PVMBG

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Lascar - photo Sernageomin

Lascar - photo Sernageomin

In northern Chile, the Lascar volcano, which is still on alert "Verde" , has thermal anomalies; they have been reported by the MIROVA site since 21.11.2018 with a peak of 52 MW on 5 December.

This increase in heat flux is concomitant with another of the sulfur dioxide emissions, detected by the Sentinel 5P-Tropomi satellite.

Lascar - thermal anomalies from 21.11 to 06.12.2018 / 3h - Doc.Mirova Modis

Lascar - thermal anomalies from 21.11 to 06.12.2018 / 3h - Doc.Mirova Modis

Lascar - sulfur dioxide emissions on 22.11.2018 - image Sentinel 5P Tropomi via Simon Carn

Lascar - sulfur dioxide emissions on 22.11.2018 - image Sentinel 5P Tropomi via Simon Carn

The Sernageomin reported in its last report (October 1 to 31) 11 VT earthquakes associated with rock fracture at a depth of 7.6 km, and 140 LP earthquakes in relation to the dynamics of internal fluids.

On the webcams, a recurrent degassing at the central crater, with a predominant magmatic component, is observed, rising about 650 meters above the active crater.

Thermal camera's glow is visible at night.

Sources: Sernageomin and Sentinel 5P / Simon Carn

Lascar - nocturnal glow within active crater - webcam 06.12.2018 / 7h04 Sernageomin

Lascar - nocturnal glow within active crater - webcam 06.12.2018 / 7h04 Sernageomin

At Veniaminof, where the eruption continues, analysis of a December 2 satellite image shows a third lava lobe extending a short distance on the southeast flank of the intra-caldera cone.

A continuous low level tremor is detected in the last few days.

Alert levels remain unchanged.

Source: AVO

Veniaminof - plume over cone and tephra / ash deposits up to Perryville - Doc.Dietterich, Hannah / AVO; ESA Sentinel-2 on 22.11.2018 / 21:48 

Veniaminof - plume over cone and tephra / ash deposits up to Perryville - Doc.Dietterich, Hannah / AVO; ESA Sentinel-2 on 22.11.2018 / 21:48 

In Fuego, the day of December 5 was marked by a few explosions accompanied by plumes of gray ash at a height of 4,500-5,000 meters asl. dispersing to the west and southwest over 25 km.

Incandescent impulses are reported at a height of 150-200 meters above the crater, generating fallout in the vicinity of the crater and to the main barrancas.

Small ash falls are reported in the leeward areas.

Fuego - eruptive plume from 05.12.2018 - photo Conred

Fuego - eruptive plume from 05.12.2018 - photo Conred

At Pacaya, strombolian activity is characterized by explosions with ejections 25-50 meters above the crater falling around the Mackenney cone, which feed a bifid lava flow towards Cerro Chino, which reaches about 200 meters.

 

Source: Insivumeh

 Pacaya - Strombolian activity : ash plume and lava flow - photo Claudia Ruppitsch / Instagram 04.12.2018

 Pacaya - Strombolian activity : ash plume and lava flow - photo Claudia Ruppitsch / Instagram 04.12.2018

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
 Kilauea East rift zone - aligned cones degassing, in Leilani Estates- photo Extreme Exposure 20.11.2018

Kilauea East rift zone - aligned cones degassing, in Leilani Estates- photo Extreme Exposure 20.11.2018

In Kilauea, no more active lava observations since September 4th ... on the basis of the dritères of the Global Volcanism Program, the eruption on the Lower East Rift Zone can be considered to be over.

Kilauea remains an active volcano, and geophysical data continues to show movements in the magmatic system, including a recharge of the East Rift Zone.

The danger remains, the area under effective control, and the closing of the lava field and vents, and its prohibition of access, remain in force, except with the express authorization of the Civil Defense.

For now, the volcanic alert level is Adisory and the yellow aviation code.

 

Source: HVO

Kilauea East rift zone - measurement of gas emissions by a drone near the cone on fissure 21 - Doc. USGS

Kilauea East rift zone - measurement of gas emissions by a drone near the cone on fissure 21 - Doc. USGS

At Etna, a Strombolian activity coupled with the emission of a small lava flow by the NSEC "puttusiddu" continues modestly; a small cone has formed inside the mouth.

Sources: Boris Behncke, Salvo Virzi and Gio Giusa

Etna - Strombolian activity of the NSEC puttusiddu 03.12.2018 - photo Salvo Virzi

Etna - Strombolian activity of the NSEC puttusiddu 03.12.2018 - photo Salvo Virzi

Etna - the intracratic cone on the NSEC flank and the lava flow 04.12.2018 - photo Gio Giusa

Etna - the intracratic cone on the NSEC flank and the lava flow 04.12.2018 - photo Gio Giusa

Etna - the intracratic cone on the NSEC flank and the lava flow 05.12.2018 - photo Gio Giusa

Etna - the intracratic cone on the NSEC flank and the lava flow 05.12.2018 - photo Gio Giusa

The dome of Merapi, in continuous growth, presents on the images of Planet Labs of December 1 an intriguing vent or a collapse structure under its perimeter.

These images were not commented by the PVMBG, which informs a seismicity characterized this December 4 by 50 earthquakes of eruption, one earthquake of emission, 5 earthquakes of low frequency, 8 hybrid earthquakes, a shallow volcanic earthquake and 2 distant tectonic earthquakes. The dome is surmounted by a white degassing at 50 meters above the summit.

 

Sources: PVMBG & Planet Labs / via Simon Carn

Merapi - a strange dark area under the dome ... vent or collapse feature - photo Planet LAbs / via Simon Carn

Merapi - a strange dark area under the dome ... vent or collapse feature - photo Planet LAbs / via Simon Carn

The rest of the volcanic news is summarized on the Volcanodiscovery map below.

Volcanoes in activity on 04.12.2018 - Doc. VolcanoDiscovery

Volcanoes in activity on 04.12.2018 - Doc. VolcanoDiscovery

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Turrialba - 03.12.2018 / 12h05-12h10 - photo from the summit of the volcano by Jean Paul Calvo and Luis Fernando Brenes / RSN

Turrialba - 03.12.2018 / 12h05-12h10 - photo from the summit of the volcano by Jean Paul Calvo and Luis Fernando Brenes / RSN

An eruption, energetic but of low amplitude, occurred on December 3 from 12:05 in Turrialba, accompanied by a plume of ash that rose 500 meters above the crater.

At the time of the episode, two RSN officials were close to the active crater engaged in maintenance work, and were able to take pictures from an unusual point of view.

 

Sources: RSN & Ovsicori

The snowy eastern flank of Chiles seen from Tulcán - photo 28.06.2014, B. Bernard / IGEPN

The snowy eastern flank of Chiles seen from Tulcán - photo 28.06.2014, B. Bernard / IGEPN

The observatory Pasto / IGEPN recorded this December 3 from 1am. local time a new swarm of volcano-tectonic earthquakes at the Chiles-Cerro Negro of Mayasquer complex, located on the border between Ecuador and Colombia. It is characterized by an average of 100 earthquakes per hour, with a MLv magnitude of 2.4 for the strongest.

The volcano, which last erupted in 1936, has a reduced activity with the presence of seismic activity and of hot springs and solfataras.

 

Source: IGEPN Pasto

Complex Chiles-Cerro Negro Mayasquer - seismic swarm of 03.12.2018 / from 01h local - Doc.IGEPN

Complex Chiles-Cerro Negro Mayasquer - seismic swarm of 03.12.2018 / from 01h local - Doc.IGEPN

No notable change in Fuego activity, characterized by 5 to 8 moderate explosions per hour, accompanied by light gray plumes at 4,300 m asl. dispersing to a western sector, and ash falls on leeward villages.

The ejections of incandescent materials 150-200 m above the crater generate moderate to strong avalanches in its surroundings, and are accompanied by shock waves.

Photos on Planet shows an enlargement of the diameter of the summit crater following volcanic activity, between November 20th and 30th.

 

Sources: Insivumeh & Conred

 Fuego - 03.12.2018 - Insivumeh photo

Fuego - 03.12.2018 - Insivumeh photo

Fuego - evolution of the summit crater between 20 and 30 November 2018 - Doc. Planet
Fuego - evolution of the summit crater between 20 and 30 November 2018 - Doc. Planet

Fuego - evolution of the summit crater between 20 and 30 November 2018 - Doc. Planet

At Sabancaya, volcanic activity between 26 November and 2 December is considered moderate, with an average of 21 explosions per day, accompanied by plumes of gas and ash at 2,500 meters maximum above the summit, dispersing over 30 km .

Seismicity is characterized by LP earthquakes, associated with internal fluid movements, and hybrid earthquakes, associated with the rise of magma.

The flow of sulfur dioxide remains significant, with 4,600 tons / day, recorded on November 28th. Slight inflation is reported, as well as small thermal anomalies between 2 and 19 MW.

The alert level remains in Naranja.

 

Sources: IG Peru, OVI, Ingemmet

Sabancaya - summary of the activity between 26.11 and 02.12.2018 - Doc.IG Peru, OVI, Ingemmet

Sabancaya - summary of the activity between 26.11 and 02.12.2018 - Doc.IG Peru, OVI, Ingemmet

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Publié le par Bernard Duyck
Publié dans : #volcanic activity

During the last 24 hours, 51 exhalations were recorded at Popocatépetl, as well as three minutes of harmonic tremor.

On december 2, three explosions were observed accompanied by ejection of incandescent fragments on the flanks of the volcano and plumes of ash reaching 2,500 meters above the crater: the first at 5:09, the second at 9:22, and the third at 15:45.

Popocatépetl - explosion of 02.12.2018 at 5:09 - 5h10 - webcamsdeMexico - a click to enlargePopocatépetl - explosion of 02.12.2018 at 5:09 - 5h10 - webcamsdeMexico - a click to enlarge

Popocatépetl - explosion of 02.12.2018 at 5:09 - 5h10 - webcamsdeMexico - a click to enlarge

Popocatépetl - explosion of 02.12.2018 at 9:22 - WebcamsdeMexico

Popocatépetl - explosion of 02.12.2018 at 9:22 - WebcamsdeMexico

Popocatépetl - explosion of 02.12.2018 at 03:45 pm - WebcamsdeMexico

Popocatépetl - explosion of 02.12.2018 at 03:45 pm - WebcamsdeMexico

Meanwhile, a constant emission of water vapor is noticed, with dissipation to the northeast.

The alert level remains at Amarillo Fase 2, along with the recall of instructions not to access the volcano due to the danger of falling ballistic fragments and lahars in case of rain.

 

Sources: Cenapred & Segob

Villarica - pyroclastic cone at the bottom of the crater - POVI images 25.11.2018

Villarica - pyroclastic cone at the bottom of the crater - POVI images 25.11.2018

At Villarica, Volcanes de Chile reports at the end of November the presence of a small active pyroclastic cone at the bottom of the crater, marked by a warmer zone.

Source: POVI 02.12.2018 / 23h

Manam - mild to moderate thermal anomalies on 29.11.2018 / 01.12.2018 - Doc.Mirova

Manam - mild to moderate thermal anomalies on 29.11.2018 / 01.12.2018 - Doc.Mirova

In Papua New Guinea, the Mirova site reports a mild to moderate thermal anomaly on 25.11, 29.11 and 01.12.2018 on Manam.

A Sentinel 2 image of December 1 shows a bluish plume surmounting the occasional cloud cover over Manam.

Manam - blue plume on 01.12.2018 - image Sentinel 2 bands 12,11,4 - one click to enlarge

Manam - blue plume on 01.12.2018 - image Sentinel 2 bands 12,11,4 - one click to enlarge

Still off the Big Island, Kadovar volcano, in orange aviation code, is the seat of ash emissions spotted by the Himawari 8 / VAAC Darwin satellite, extending to the southeast.

Sources: Mirova, Sat.Himawari 8 and Sentinel2, VAAC Darwin

Kadovar - volcanic ash advisory for 3 and 4.12.2018 - Doc. VAAC Darwin

Kadovar - volcanic ash advisory for 3 and 4.12.2018 - Doc. VAAC Darwin

Anak Krakatau - seismicity on 02.12.2018 - Doc.Magma Indonesia

Anak Krakatau - seismicity on 02.12.2018 - Doc.Magma Indonesia

In Krakatau, the week of 26 November to 2 December saw its nights marked by incandescent explosions 200 meters above the summit; during the day, a black ash plume is noted between 100 and 700 meters above the summit, often covered with fog.

Seismicity is characterized by 154 eruptions, 45 earthquakes, volcanic earthquakes, 60 shallow and 80 deep, 57 episodes of harmonic tremor and a continuous tremor of amplitude between 1 and 58 mm.

 

Source: PVMBG

Compilation of volcanic lightning in the Krakatau plume between 12 and 15 November 2018 - Galig Jati / volcanodiscovery images

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Publié le par Bernard Duyck
Publié dans : #Sismologie, #volcanic activity
Aerial view of the southern part of Mayotte. - Alamy Stock photo via Nat Geographic

Aerial view of the southern part of Mayotte. - Alamy Stock photo via Nat Geographic

A seismic activity has affected the island of Mayotte since the beginning of May 2018. These earthquakes form a swarm with epicentres grouped at sea, 30 to 60 km east of the coast of Mayotte. The vast majority of these earthquakes are of low magnitude, but several events of moderate magnitude (at most M5.9) have been strongly felt by the population and have damaged some buildings. Since the month of July the seismic activity has decreased but a seismicity persists which certain earthquakes felt.

Location of earthquakes from May 10 to June 20, 2018. The location of earthquakes has not changed since the beginning of the crisis. © BRGM

Location of earthquakes from May 10 to June 20, 2018. The location of earthquakes has not changed since the beginning of the crisis. © BRGM

In November, the month was particularly active with two earthquakes of Magnitude> 4 felt, November 19 (M4.5) and November 27 (M5.0).

In parallel, data from the Teria network's GPS stations installed on the island of Mayotte, which are distributed by the RGP of the Institut Géographique National (IGN), indicate since July an overall displacement of about 9 cm to the east and subsidence (subsidence) of about 8 cm. Automatic and daily calculations have been set up at the OVPF (via the Gipsy software) in order to follow these deformations, as well as the source at their origin.

Thus for the month of November, the source of "depressurization" at the origin of these movements could be located about 32 km east of Mayotte and about 37 km deep.

As initially suggested by the ENS, the hypothesis of a source of deflation corresponding to the emptying of a magmatic reservoir at the level of the seismic zone seems most likely. On November 11, 2018, a long period seismic signal was recorded, and will confirm this volcanic hypothesis.

Mayotte - earthquake of 11.11.2018 - Doc. Infogram

Mayotte - earthquake of 11.11.2018 - Doc. Infogram

Seismic activity of Mayotte - Location of the source (best model resulting from a "Mogi" type of modeling) at the origin of the movements recorded in November on GPS stations of Mayotte. Modeling realized by F. Beauducel (IPGP / IRD) and OVPF-IPGP.

Seismic activity of Mayotte - Location of the source (best model resulting from a "Mogi" type of modeling) at the origin of the movements recorded in November on GPS stations of Mayotte. Modeling realized by F. Beauducel (IPGP / IRD) and OVPF-IPGP.

Mayotte - earthquake swarm, #InSAR, published crude composite. - BRGM via Matarikipax Twitter

Mayotte - earthquake swarm, #InSAR, published crude composite. - BRGM via Matarikipax Twitter

"Although the hypothetical flow is important [...], the place where the magma (extracted from the deep reservoir) is placed on the surface (or under the surface, in the crust) is currently unknown. this date would be of the order of 1.3 km3, which is very high and never observed before at sea bottom, if it is indeed an eruption ", says Pierre Briole, physicist at the ENS

The BRGM antenna in Mayotte reports in an interview with Clicanoo that "for several months, the scientific community has come together to understand the phenomenon and answer the questions that arise from it.The deployment of new instruments on land and at sea to improve the detection and localization of the observed earthquakes is under study.In parallel with this observation mission, a request for an oceanographic campaign was made to explore both the swarm zone between Mayotte and Madagascar and, more widely, the Comoros region. " The time to be expected is of the order of one to two years.

(from Clicanoo - source ref.)

 

Sources:

- OVPF - Seismic crisis in Mayotte / Monthly bulletin

- ENS Geosciences - Volcanology - link

- BRGM - Earthquake swarm in Mayotte: situation points - link

- Clicanoo - Seismic activity: in Mayotte, the volcanic hypothesis is precise - link

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologie, #Tectonique
Mayon - archive image 02.2018 / © Thierry Sluys.

Mayon - archive image 02.2018 / © Thierry Sluys.

Mayon seismometers recorded 5 volcanic earthquakes in the past 24 hours, including one in relation to an ash emission on November 30 from 9:41 am lasting one minute; the emission of the greyish plume was followed by steam and gas plumes towards the SW.

The flow of sulfur dioxide is measured at an average of 1,377 tons / day. The inflation of the southwestern sector of the volcano is still noted.

The level 2 alert remains in effect.

 

Source: Phivolcs

Merapi - the dome the 29.11.2018 / 8h18 - photo PVMBG

Merapi - the dome the 29.11.2018 / 8h18 - photo PVMBG

At Merapi, the volume of the lava dome reached 29 November 329,000 m³, for a growth rate of about 2,500 m³ per day, down slightly.

For the day of November 30, the PVMBG informs of a white degassing at about fifty meters above the summit, and a moderate seismicity.

The activity level remains at 2 / waspada.

 

Sources: BPPTKG / PVMBG
 

News from Mayon, Merapi, La Fournaise - and Tectonic Earthquake in Alaska.

The month of November 2018 will have been calm at Piton de la Fournaise, marked by a low seismicity under the summit craters and a stop of the inflation of the building. This testifies to the stopping (or at least slowing down) of the magmatic transfers from the deep zones to the more superficial zones. Moreover, the decrease in CO2 fluxes in the far-field soil since May 2018 suggests that the transfers of new magma towards the deep zones (mantle) seem to have ceased as well. Nevertheless, the trend reversal (ie an increase in CO2 fluxes in the far-field soil) observed since October 26, will be to follow in the coming weeks to determine whether a resumption of transfers of new magma to deep zones begins.

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

The information in this document may not be used without explicit reference.

Piton de La Fournaise - the crater Dolomieu, with in the background, the ramparts of Enclos Fouqué and the Piton des Neiges - photo archive © Bernard Duyck

Piton de La Fournaise - the crater Dolomieu, with in the background, the ramparts of Enclos Fouqué and the Piton des Neiges - photo archive © Bernard Duyck

A Magnitude 7.0 earthquake occurred on November 30 at 17:29 UTC 13 km north of Anchorage, Alaska. The hypocenter is located at a depth of 40.9 km according to the USGS.

This is a place where the Pacific tectonic plate moves northwest at about 60mm / yr and enters subduction below the North American plate.

The earthquake was strong enough to cause ruptures of slopes in a restricted area because of the low relief ... the material damage is however important.

Waiting for replicas that are not going to happen, a more complete article will follow.

NB: activity of volcanoes in current regional eruption continues without changes

 

Sources:

- USGS earthquake hazards program and EMSC

- AGU - Landslide blog - D.Petley

 Alaska - epicenter of the M 7.0 earthquake on 30.11.2018 / 17h29 - Doc. EMSC

 Alaska - epicenter of the M 7.0 earthquake on 30.11.2018 / 17h29 - Doc. EMSC

Alaska -30.11.2018 - photo USGS-Josh Bierma-Hunter Sloan Sizemore
Alaska -30.11.2018 - photo USGS-Josh Bierma-Hunter Sloan Sizemore

Alaska -30.11.2018 - photo USGS-Josh Bierma-Hunter Sloan Sizemore

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Publié le par Bernard Duyck
Publié dans : #volcanic activity
Nevados of Chillan - 29.11.2018 / 13:40 local - photo via Terremoto in Talcahuano

Nevados of Chillan - 29.11.2018 / 13:40 local - photo via Terremoto in Talcahuano

An explosion marked the Nevados de Chillan complex this November 29 at 13:38 local; the plume emitted was visible from several places in the region. Satellite images from ESA show an increase in the area of ​​thermal anomalies associated with the active lava dome in the Nicanor crater.

Explosions of varying magnitude continue, and nighttime glow is observed on the webcam.

The alert level remains in Naranja, with a prohibited area of ​​3 km radius around the active crater.

 

Sources: photos Sernageomin, via volcanes of Chile and Terremoto in Talcahuano.

Nevados de Chillan - 29.11.2018 - increase in the area of ​​thermal anomalies associated with the dome - Doc. Sentinel Hub / ESA

Nevados de Chillan - 29.11.2018 - increase in the area of ​​thermal anomalies associated with the dome - Doc. Sentinel Hub / ESA

Nevados de Chillan - continuation of the activity on 29.11.2018 / 16:38 and incandescence night on the 30.11.2018 / 7:14 - webcam Sernageomin - one click to enlarge thumbnailsNevados de Chillan - continuation of the activity on 29.11.2018 / 16:38 and incandescence night on the 30.11.2018 / 7:14 - webcam Sernageomin - one click to enlarge thumbnails

Nevados de Chillan - continuation of the activity on 29.11.2018 / 16:38 and incandescence night on the 30.11.2018 / 7:14 - webcam Sernageomin - one click to enlarge thumbnails

In Guatemala, heavy rains on 28 and 29 November on the Fuego led to the descent of strong, hot lahars, accompanied by the smell of sulfur and degassing columns, towards the Seca, Santa Teresa and El Mineral barrancas. The lahars carried ash, blocks 1 to 3 meters in diameter, volcanic materials deposited during the last eruptions.

Paths to different villages have been affected: between San Pedro Yepocapa and Sangre de Cristo, between Finca Palo Verde and El Porvenir. At Sainte-Sophie Yepocapa, a vehicle that was trying to pass ford was surprised and destroyed,  fortunately without victims.

 

Source: Insivumeh special bulletin of 29.11.2018 / 13.40 and Canal 5 of Yepocapa.

Car destroyed in Saint Sophia Yepocapa by a Fuego's lahar - photos Canal 5 of Yepocapa
Car destroyed in Saint Sophia Yepocapa by a Fuego's lahar - photos Canal 5 of Yepocapa

Car destroyed in Saint Sophia Yepocapa by a Fuego's lahar - photos Canal 5 of Yepocapa

Volcanic activity on Ambae / Vanuatu is again stable according to the VMGD, which maintains the volcanic alert at level 2, together with a 2 km safety zone around the Manaro Voui Lake vent, and zones in yellow.

Ambae - during a thinning on 25.11.2018 - Sentinel-2 images nat colors image and zoom on Lake Voui. - a click to enlarge
Ambae - during a thinning on 25.11.2018 - Sentinel-2 images nat colors image and zoom on Lake Voui. - a click to enlarge

Ambae - during a thinning on 25.11.2018 - Sentinel-2 images nat colors image and zoom on Lake Voui. - a click to enlarge

It must be remembered that the eruptions resulted in two evacuations involving 11,000 people in the last 18 months.

The first evacuation took place in September 2017, followed by a partial return; In March 2018, the eruption resumed, leading to a new voluntary evacuation at first, then mandatory in late July.

A government press release said the population should not return to the island and that Ambae chiefs would be held accountable for returning members of their communities.

Ambae people should focus their efforts on building a second home on a nearby island, he said.

Government employees will not be returned to Ambae as their safety can not be guaranteed.

However, the government has confirmed that a multi-sectoral assessment of the island will take place in the next two weeks.

 

Sources: Radio NZ & Sentinel 2

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