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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 : #volcanic activity

The fissure eruption of Cumbre Vieja continues to show a Strombolian mechanism, with simultaneous explosive and effusive phases

The delta that was formed has an area of ​​27.7 ha., Increasing north and south sideways.

The new lava flow generated by the last two vents opened on October 1 advances in lateral contact with the previous flows. towards the main flow which remains stable.

The eruptive column rises to 4,500 meters.

La Palma / Cumbre Vieja - activity in progress as of October 3, 2021 - photo InVolcan

La Palma / Cumbre Vieja - activity in progress as of October 3, 2021 - photo InVolcan

In the past 24 hours, 21 earthquakes have been recorded, with a hypocenter at 10-14 km. The tremor remains generally stable, with a small increase around 3 p.m.

The sulfur dioxide emission associated with the volcanic plume (visible fumes) continues to record relatively high values ​​and in phase with the eruptive process, reaching values ​​of 2,330 tonnes per day. The diffuse emission of carbon dioxide associated with the 220 km2 of the volcanic ridge of Cumbre Vieja (non-visible emissions) reached values ​​of 1,870 tonnes per day.

La Palma / Cumbre Vieja - number and magnitude of earthquakes - & variations of the tremor - Doc. IGNes - one click to enlargeLa Palma / Cumbre Vieja - number and magnitude of earthquakes - & variations of the tremor - Doc. IGNes - one click to enlarge

La Palma / Cumbre Vieja - number and magnitude of earthquakes - & variations of the tremor - Doc. IGNes - one click to enlarge

The ash-covered surface covers more than 3,000 ha.

In the upper area of ​​the channeled flow, a roof begins to develop, forming a lava tunnel ... the flow will be stabilized and possible overflows avoided.

It is estimated that 1,500 buildings were affected by the eruption; lava cut the irrigation pipeline to the most productive agricultural area of ​​Las Hoyas-El Remo.

 

Sources: InVolcan, DSN, Copernicus, Volcanes y Ciencia Hoy, Pevolca, Gobierno de Canarias

La Palma / Cumbre Vieja - atmospheric gravity waves - photo Ana Lozano via Picazomario / 01.10.2021

La Palma / Cumbre Vieja - atmospheric gravity waves - photo Ana Lozano via Picazomario / 01.10.2021

La Palma / Cumbre Vieja - atmospheric gravity waves seen from space by Nasa worldview / 01.10.2021

La Palma / Cumbre Vieja - atmospheric gravity waves seen from space by Nasa worldview / 01.10.2021

A new measurement of the lava volume was taken at Fagradalsfjall on September 30. Aerial photographs were also taken with the Hasselblad camera of the Institute of Natural History from the Fisfélag plane. Terrestrial models were made based on these measurements and they were compared to older data.

Fagradalsfjall - the parameters of the eruption at 30.09.2021 - Doc. http://jardvis.hi.is/eldgos_i_fagradalsfjalli

Fagradalsfjall - the parameters of the eruption at 30.09.2021 - Doc. http://jardvis.hi.is/eldgos_i_fagradalsfjalli

The results show that there has been no lava flow from the crater, possibly since the evening of September 18. They confirm that the rash has completely stopped.

The volume of lava emitted is now 150 million cubic meters and the area covered by the lava is 4.85 square kilometers.

According to the turbulence and visibility measurements towards the crater, the eruption was in progress after September 18. A new magma therefore appeared in about a day from the first measurement. It is not known how big it was, probably less than a million cubic meters.

After the ascent into the crater stopped on the evening of September 18, there was a thickening of several meters in the southern part of Geldingadalur and up to the Nátthaga front. At the same time, the lava plain west of the crater, north of Geldingadalur, sank about 5-7 meters. The volume of material that has disappeared from the northern end of Geldingadalur is as large as the volume that has been added in the southern part and down to Nátthaga. There was therefore a displacement within the lava.

While there has been no flow of magma from the crater, the flow within the lava over the past 12 days has averaged 1 m³ / s. There is certainly molten magma moving, but only because of the movement within the lava.

 

Source: http://jardvis.hi.is/eldgos_i_fagradalsfjalli

Kilauea / Halema'uma'u lava lake on 02.10.2021 / 06h00 - USGS-HVO webcam

Kilauea / Halema'uma'u lava lake on 02.10.2021 / 06h00 - USGS-HVO webcam

The Kīlauea volcano is erupting.

Lava continues to emerge from several vents along the floor and western wall of Halema'uma'u Crater.
Sulfur dioxide emission rates remain high and were estimated at around 12,900 tonnes per day as of October 1, 2021. Seismicity is high but stable. Summit tiltmeters continued to register a slowdown in deflationary tilt over the past 24 hours.


In total, the surface of the lava lake has risen by about 26 meters since the start of the eruption. Localized and discontinuous crustal collapse continues (a process by which the cold lava crust on the surface of the lava lake is replaced by a less dense liquid from below, causing the crust to sink into the lava underlying the lake). Field teams this morning measured fountain heights of around 7 meters from the main vent and 1 to 2 meters from the southernmost vents. Occasional fountain height gusts have been observed over the past 24 hours, including a gust this morning with estimated heights of 50 to 60 meters.

Current volcanic alert level: Warning ; Current aviation code: Red.

 

Source: HVO-USGS

Yellowstone - Norris geyser basin - photo archives © Bernard Duyck 2009

Yellowstone - Norris geyser basin - photo archives © Bernard Duyck 2009

In September 2021, the University of Utah Seismographic Stations, responsible for operating and analyzing the Yellowstone Seismic Network, located 283 earthquakes in the Yellowstone National Park area. The biggest event of the past month was a minor magnitude 3.2 earthquake located 15.6 miles south of Old Faithful, Yellowstone National Park, on September 8 at 11:01 a.m. MDT.
The September seismicity in Yellowstone was marked by 4 earthquake swarms. Earthquake sequences like these are common and account for about 50% of the total seismicity in the Yellowstone area.
Yellowstone's seismic activity remains at background levels.

 

The Yellowstone Caldera subsidence, which has been going on since 2015, came to a halt during the summer months, reflecting the seasonal groundwater recharge. Each summer, the snowmelt water causes the ground to swell slightly, resulting in a pause in subsidence trends or even a slight uplift (less than 1 cm / fraction of an inch).

In the Norris Geyser Basin area, no significant uplift or subsidence has been detected by a nearby GPS station since early 2020.

 

Steamboat Geyser erupted twice in September, September 11 and 28, bringing the total number of eruptions for the year to 15. Eruptions are irregular and much less frequent than in the previous three summers. which may indicate that the geyser is approaching a period of calm.

 

Source: Yellowstone volcano observatory

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