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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 Ovsicori reports small emissions at a low height and almost daily by the Turrialba between July 1 and 7, with the exception of July 3.

On July 6 at 9 a.m., a plume of gas and ash reached a few hundred meters, causing localized ash falls.

On July 7, no significant change in gases was observed. However, the CO2 / SO2 ratio fluctuated from 12.3 to 10.3; while the H2S / SO2 ratio remains between 0.3 and 0.4. However, the SO2 concentration varies between 3.3 and 4.6 ppm. During the first hours of today, passive degassing was observed. However, there are sporadic ash emissions, the last reported yesterday morning.

 

Source: Ovsicori-UNA

The Alaska volcano Observatory has posted a GeoEye-1 satellite image which documents the consequences of an explosion in early June at the Cleveland volcano.

Regional infrasound sensors recorded an explosion during the night hours of June 1-2, 2020. A small ash cloud was observed 22,000 feet above sea level drifting south. The eruption exploded the dome in January 2019 and a large amount of material from the summit crater. Volcanic debris also extends over the eastern flank of the volcano and the northern flank. The orange dots on the satellite image indicate the location of the ballistic ejected bombs and blocks associated with the June explosion of the summit crater.

At the Cleveland Volcano, episodes of lava outpouring and explosions can occur without prior warning. The explosions are normally short-lived and pose only a risk to aviation in the immediate vicinity of the volcano. No activity was seen on cloudy satellite images or detected on regional geophysical networks during the last day.

 

Source: AVO

The Ovsicori reports small emissions at a low height and almost daily by the Turrialba between July 1 and 7, with the exception of July 3.

On July 6 at 9 a.m., a plume of gas and ash reached a few hundred meters, causing localized ash falls.

On July 7, no significant change in gases was observed. However, the CO2 / SO2 ratio fluctuated from 12.3 to 10.3; while the H2S / SO2 ratio remains between 0.3 and 0.4. However, the SO2 concentration varies between 3.3 and 4.6 ppm. During the first hours of today, passive degassing was observed. However, there are sporadic ash emissions, the last reported yesterday morning.

 

Source: Ovsicori-UNA

Cleveland - photo 22.06.2020 22.53 UTC / Matt Loewen / AVO

Cleveland - photo 22.06.2020 22.53 UTC / Matt Loewen / AVO

Cleveland satellite image - GeoEye-1, June 22, 2020. The orange dots indicate the location of the ballist-ejected bombs and blocks associated with the June 2, 2020 explosion of the summit crater. The most distant bombs are about 1300-1400 m from the vent. Mass flow deposits extending from the summit crater are also evident in the image. Some of them may have resulted from the landing of hot debris on the snow, causing the debris / snow mixture to melt and re-mobilize. - photo Chris Waythomas / AVO

Cleveland satellite image - GeoEye-1, June 22, 2020. The orange dots indicate the location of the ballist-ejected bombs and blocks associated with the June 2, 2020 explosion of the summit crater. The most distant bombs are about 1300-1400 m from the vent. Mass flow deposits extending from the summit crater are also evident in the image. Some of them may have resulted from the landing of hot debris on the snow, causing the debris / snow mixture to melt and re-mobilize. - photo Chris Waythomas / AVO



 

Turrialba - passive degassing on 07.07.2020 / 3:38 p.m. - Ovsicori webcam

Nishinoshima - image Nasa Eosdis Worldview 09.07.2020

Nishinoshima - image Nasa Eosdis Worldview 09.07.2020

The eruption continues on Nishinoshima.

According to the NHK news agency, which repeats an announcement by researchers from the Geospatial information authority of Japan, the southern part of the island has grown at least 150 meters between June 19 and July 3.

The Geos-5 satellite shows a serious vortex of sulfur dioxide, managed by a high pressure nucleus on the Pacific in the east of Japan; this SO2 cloud is diluted further north over the Aleutians and then follows the coasts of Canada. (via windy.com)

 

Sources: Mirova, Nasa Worldview, NHK, Windy

Nishinoshima - Volcanic ash advisory 09.07.2020 - Doc. VAAC Tokyo

Nishinoshima - Volcanic ash advisory 09.07.2020 - Doc. VAAC Tokyo

In Iceland, disturbances affect the northern fjords and the Myrdalsjökull in the south.

Tjörnes FZ - location and magnitude of earthquakes as of 09.07.2020 / 07h05 - Doc. IMO
Tjörnes FZ - location and magnitude of earthquakes as of 09.07.2020 / 07h05 - Doc. IMO
Tjörnes FZ - location and magnitude of earthquakes as of 09.07.2020 / 07h05 - Doc. IMO

Tjörnes FZ - location and magnitude of earthquakes as of 09.07.2020 / 07h05 - Doc. IMO

Earthquakes at the mouth of Eyjafjörður - Tjörnes fracture zone

On July 8 at 5:41 p.m., an earthquake of magnitude 4.2 occurred approximately 13 km from the CP of Gjögurtá. The Icelandic Meteorological Office has received reports that the earthquake occurred in many parts of the Eyjafjörður region.

The seismic swarm is still in progress. Since the onset of the crisis on June 19, the IMO has located more than 10,000 earthquakes. Three earthquakes larger than 5 were detected in the hryvnia, the largest being on June 21, the size of 5.8 beds 30 km NNE from Siglufjörður. Other earthquakes of magnitude greater than 5 were 5.6 and 5.4 magnitude on June 20 and were located more than 20 km northeast of Siglufjörður.

There are still many small earthquakes in the region, and larger earthquakes are likely to occur.

Múlakvísl - the river flow of summer 2019 - Doc. Mbl.is

Múlakvísl - the river flow of summer 2019 - Doc. Mbl.is

Myrdalsjökull

The electrical conductivity at Múlakvísl has increased slowly in recent days and it is believed that the geothermal water emitted by the Mýrdalsjökull glacier infiltrates the river.

Due to geothermal heat in some areas under the glacier, water collects in pockets under the glacier, but ultimately finds its way to glacial rivers. Water contains dissolved substances and gases that give off odors and explain the conductivity of water.

Einar Bessi Gestsson, a weather specialist at the Icelandic Meteorological Office, explains that this almost always happens every summer. "This may be accompanied by gas pollution, so we send a notification like this." Farmers in the area are used to the smell, which they generally call the glacier elephant. Most of the gas pollution is at the origin of the river, at Kötlujökull, in the eastern part of Mýrdalsjökull, where vigilance is required in the lower areas.

 

Source: IMO

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