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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

At 10:41 p.m. local on March 21, an eruptive episode occurred at Sakurajima (summit crater of Minamidake), and the plume rose to 2,400 m above the edge of the crater.

Volcanic ash flows from the crater to the northeast (direction Fukuyama, town of Kirishima), and in less than an hour, a small amount in the town of Kagoshima (Sakurajima)

There is a fall of ashes which should fall in Soo City, in the prefecture of Kagoshima.
 

Source: JMA 10:49 p.m. February 21, 2002

The seismic swarm in the Reykjanes peninsula is still in progress, with earthquakes of magnitude less than 3.0; the IMO gives indications of declining inflation but still present and the situation will be reviewed by the Scientific Council of Civil Protection on February 25.

Reykjanes peninsula - location (more towards the SW point) and magnitude of the earthquakes in the swarm in progress on 21.02.2020 / 12:15 pm - Doc. IMO
Reykjanes peninsula - location (more towards the SW point) and magnitude of the earthquakes in the swarm in progress on 21.02.2020 / 12:15 pm - Doc. IMO

Reykjanes peninsula - location (more towards the SW point) and magnitude of the earthquakes in the swarm in progress on 21.02.2020 / 12:15 pm - Doc. IMO

The IMO warns, this February 21 at 10.59 GMT, against the excursions in the caves in the area of ​​Eldvörp in the peninsula of Reykjanes. Yesterday's measurements showed deadly levels of carbon dioxide (CO2) and a lack of oxygen in a cave. Many caves are present in the region, the cave in question is close to a parking lot which is a popular stop to embark on exploring the volcanic cones and craters.

Eldvörp - craters aligned on a crack - photo Iceland Review

Eldvörp - craters aligned on a crack - photo Iceland Review

The row of craters on the Reykjanes peninsula, called Eldvörp, formed during an eruption between 1211 and 1240.

A lava field from the eruption covers a large area west of the small Svartsengi and Þorbjörn mountains. The lava field stretches from the northernmost crater to the southern shore. The craters are similar to the famous Lakagigar in the Icelandic highlands although everything is on a smaller scale. The row of craters is about 10 kilometers long and consists of many craters, and some are even still hot with steam evaporating from the ground, indicating that the craters are still active and that the magma is still hiding underneath.


vidéo : https://www.youtube.com/watch?v=MLJdAFR4Seg

Sources: IMO & Icelandic volcanoes

Chaparrastique - thermal anomalies on 22.02.2020 / 04h40 - Doc Mirova

Chaparrastique - thermal anomalies on 22.02.2020 / 04h40 - Doc Mirova

Starting at 7:00 p.m. yesterday February 20 at 7:50 a.m. Friday 21, the Network of local observers reported the occurrence of a series of rumblings from the Chaparrastique volcano. Monitoring data indicates that the volcano has exhibited a change in behavior, evidenced by the increase in the amplitude of microseisms and slight gas emissions by its central crater. The seismicity recorded in the volcano shows signs that may be related to fractures and small internal explosions of the volcano, which indicates an increase in its internal pressure, with the possibility of the appearance of a more significant degassing which can be accompanied by small ash fumes, which, if they occur, will preferably be transported to the southwest flank of the volcano.

 

Sources: MARN / Salvador & Mirova

 Seismicity of the Chaparrastic volcano recorded from February 14 to 21, 2020, associated with fractures and small internal explosions due to the movement of gases and fluids. The number of earthquakes oscillates between 10 and 15 earthquakes per hour, which is normal in this volcano. - Doc. MARN

 Seismicity of the Chaparrastic volcano recorded from February 14 to 21, 2020, associated with fractures and small internal explosions due to the movement of gases and fluids. The number of earthquakes oscillates between 10 and 15 earthquakes per hour, which is normal in this volcano. - Doc. MARN

Over the past week, HVO seismometers have recorded 44 small magnitude earthquakes under the upper altitudes of the Mauna Loa volcano. The strongest was a magnitude 2.2 event on February 16, about 7 kilometers below the surface. Most of the events occurred at shallow depths less than 5 km below the surface of the volcano.

Global positioning system (GPS) measurements show continued slow top inflation, consistent with magma supply from the volcano's shallow storage system.

Gas concentrations at the sulfur cone monitoring site in the southwest rift zone remain stable. The temperatures of the fumaroles measured both at the sulfur cone and at the top did not change significantly.

These signals show that magma is entering the shallow storage system. However, these data, as well as the seismicity and SO2 emission rates do not suggest an impending eruption.

 

Sources: HVO and ESA / Sentinel 1A & 1B

Hawaii- Big Island - data from the European Space Agency's (ESA) Sentinel-1A and Sentinel-1B satellites as of March 31, 2019 and January 31, 2020 produced this interferogram. Each fringe, or band of colors, represents 2.83 cm (1.1 inches) of change in range (the distance between the satellite and the ground). Counting the fringes gives the change in total range between two satellite passes. At point (A), the ground moved closer to the satellite by 7 cm (2.75 inches) between the two passages due to the inflation of the shallow magma chamber under the summit of Mauna Loa. The fringes near point (B) at the top of Kīlauea reflect the inflation of the shallow magma chamber Halema'uma'u. This inflation has been observed since mid-March 2019, with a total ratio of around 40 cm.

Hawaii- Big Island - data from the European Space Agency's (ESA) Sentinel-1A and Sentinel-1B satellites as of March 31, 2019 and January 31, 2020 produced this interferogram. Each fringe, or band of colors, represents 2.83 cm (1.1 inches) of change in range (the distance between the satellite and the ground). Counting the fringes gives the change in total range between two satellite passes. At point (A), the ground moved closer to the satellite by 7 cm (2.75 inches) between the two passages due to the inflation of the shallow magma chamber under the summit of Mauna Loa. The fringes near point (B) at the top of Kīlauea reflect the inflation of the shallow magma chamber Halema'uma'u. This inflation has been observed since mid-March 2019, with a total ratio of around 40 cm.

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