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Earth of fire

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

Publié le par Bernard Duyck
Publié dans : #Actualités volcaniques
 Agung - eruptive plume of July 24 around 12:52 pm WITA - photo via BNPB

Agung - eruptive plume of July 24 around 12:52 pm WITA - photo via BNPB

An eruption marked the Agung this July 24 at 12:52 WITA; it lasted 2 minutes and 13 seconds, and was accompanied by a plume of ash rising to 1,500 meters above the crater, before drifting to the southeast.

Seismicity is characterized by low frequency earthquakes.

The alert level remains at III / Siaga, with an orange VONA.

Sources: PVMBG & BNPB
 

Sierra Negra - Sentinel picture 2 SWIR on 16.07.2018
Sierra Negra - Sentinel picture 2 SWIR on 16.07.2018

Sierra Negra - Sentinel picture 2 SWIR on 16.07.2018

A point is made by the IGEPN on the eruption of the Sierra Negra volcano that started on June 26 this year. The emission of lava flows in the fissure Nº4 that reached the sea between July 9 and 10 and continues to enter until now is maintained. The coastline has changed and the Ecuadorian territory, until July 16th, has increased by about 1 km².

Sierra Negra - distribution of various fissures and lava flows, updated on 16.07.2018 - Doc. IGEPN 

Sierra Negra - distribution of various fissures and lava flows, updated on 16.07.2018 - Doc. IGEPN 

Sierra Negra - picture taken on 26.06.2018 from a boat in the Bahía Elizabeth illustrating the different fissures active to this day - Crack 1: is an opening located at the edge of the caldera (1070 m) in the area of ​​Chico volcano; the cracks are aligned in the west-northwest direction and tangent to the edge of the caldera; they have a length of 4 km and lava flows emitted since the beginning of the eruption, inside and outside the caldera, covered an area of ​​16.1 km2, until June 27, date of cessation of their activity. Fissure 2: located northwest of the caldera, about two kilometers under the edge of it (700 meters). It has a length of about 250 meters and has produced lava flows since the beginning of the eruption, covering an area of ​​2.3 km2 until June 27, when it seems to have completed its activity. It had an extension of about 3 km and its lava did not reach the sea. Crack 3: located west of the caldera. This crack is about 250 meters long and has been active since the beginning of the eruption, emitting lava flows that covered an area of ​​about 0.3 km2 until June 27 when it apparently concluded its activity . The lava flows had an extension of about 2 km and their lava did not reach the sea. Fissure 4: was the most active, and since the beginning of the eruption has been continuously lava flows. It is located on the northwest flank (100 m) 8 km downstream from the caldera edge. Until July 16, its lavas covered an area of ​​11.6 km2 which continues to grow at the time of publication of this report. Between 9 and 10 July, lava flows from this fissure reached the ocean and changed the Ecuadorian coast. Until 16 July, the Ecuadorian territory has increased by 0.93 km².

Sierra Negra - picture taken on 26.06.2018 from a boat in the Bahía Elizabeth illustrating the different fissures active to this day - Crack 1: is an opening located at the edge of the caldera (1070 m) in the area of ​​Chico volcano; the cracks are aligned in the west-northwest direction and tangent to the edge of the caldera; they have a length of 4 km and lava flows emitted since the beginning of the eruption, inside and outside the caldera, covered an area of ​​16.1 km2, until June 27, date of cessation of their activity. Fissure 2: located northwest of the caldera, about two kilometers under the edge of it (700 meters). It has a length of about 250 meters and has produced lava flows since the beginning of the eruption, covering an area of ​​2.3 km2 until June 27, when it seems to have completed its activity. It had an extension of about 3 km and its lava did not reach the sea. Crack 3: located west of the caldera. This crack is about 250 meters long and has been active since the beginning of the eruption, emitting lava flows that covered an area of ​​about 0.3 km2 until June 27 when it apparently concluded its activity . The lava flows had an extension of about 2 km and their lava did not reach the sea. Fissure 4: was the most active, and since the beginning of the eruption has been continuously lava flows. It is located on the northwest flank (100 m) 8 km downstream from the caldera edge. Until July 16, its lavas covered an area of ​​11.6 km2 which continues to grow at the time of publication of this report. Between 9 and 10 July, lava flows from this fissure reached the ocean and changed the Ecuadorian coast. Until 16 July, the Ecuadorian territory has increased by 0.93 km².

Eruptive activity occurred along four cracks on the north and northwest flanks, giving rise to various lava flows covering a total area of ​​approximately 30.4 km². The eruption began with lava emission through all these fissures; however, the three upper fissures (1, 2 and 3) ceased activity on June 27th.

On the other hand, the lowest fissure (Nº4) is the most active and maintains the emission of lava flows.

Since the eruption of Sierra Negra began, the intensity of eruptive activity has been variable.

Sabancaya - summary of the activity from 16 to 22 July 2018 - Doc.IG Peru, OVI, Ingemmet

Sabancaya - summary of the activity from 16 to 22 July 2018 - Doc.IG Peru, OVI, Ingemmet

In Sabancaya / Peru, the week of July 16 to 22 was characterized by moderate activity, with an average of 25 daily explosions, and ash plumes of up to 2,500 meters, dispersing over 30 km in an eastern and southern sector.
The flow of sulfur dioxide remains high, measured at 12,068 tons per day on July 18.


Source: IG Peru, OVI, Ingemmet

Kilauea East Rift Zone - 23.07.2018 - The cone and the upper lava flow on fissure 8 - photo Bruce Omori

Kilauea East Rift Zone - 23.07.2018 - The cone and the upper lava flow on fissure 8 - photo Bruce Omori

At Kilauea, the fissure 8 continues to emit its lava in the channeled flow towards the ocean; several overflows were observed northwest of the Kapho crater following a collapse at the top ... they remained confined to the existing lava field, without threatening other houses.

The lava front seems to have stabilized about 500 meters from Isaac Hale Park boat ramp.
 

Kilauea East Rift Zone - 23.07.2018 - View of the new black volcanic sandbank that formed when the flows began to encroach on Pohoiki. - photo Bruce Omori

Kilauea East Rift Zone - 23.07.2018 - View of the new black volcanic sandbank that formed when the flows began to encroach on Pohoiki. - photo Bruce Omori

Kilauea East Rift Zone - 23.07.2018 - General view of the bays south side of the lava expanses; right, the new sand bar at Bowls - on the left, the surf spot at Shacks- photo Bruce Omori

Kilauea East Rift Zone - 23.07.2018 - General view of the bays south side of the lava expanses; right, the new sand bar at Bowls - on the left, the surf spot at Shacks- photo Bruce Omori

At the top, the collapses follow one another.

The Opentopography website has published a comparison between the digital elevation models of the Halama'uma'u summit crater, between 2009 (before the current episode) and early July 2018.
 

Sources: HVO-USGS, and Opentopography

Digital elevation models of the Halama'uma'u summit crater, between 2009 (before the current episode) and early July 2018. - Photo Credits: Before NSF, NCALM - After USGS, NCALM, CRREL, State of Hawaii , FEMA

Digital elevation models of the Halama'uma'u summit crater, between 2009 (before the current episode) and early July 2018. - Photo Credits: Before NSF, NCALM - After USGS, NCALM, CRREL, State of Hawaii , FEMA

Kilauea – cratère Halema'uma'u – profil topographique  ouest-est entre 2009 et juillet 2018 – Doc. Opentopography

Kilauea – cratère Halema'uma'u – profil topographique ouest-est entre 2009 et juillet 2018 – Doc. Opentopography

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