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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
Aerial photo of the Alaid summit area on April 28, 2016, with fresh lava filling the crater, a cinder cone in the southern part of the crater, and a lava flow on the SW flank.-Photo by L. Fugura ; courtesy of IVS FEB RAS, KVERT. (via GVP) - one click to enlarge

Aerial photo of the Alaid summit area on April 28, 2016, with fresh lava filling the crater, a cinder cone in the southern part of the crater, and a lava flow on the SW flank.-Photo by L. Fugura ; courtesy of IVS FEB RAS, KVERT. (via GVP) - one click to enlarge

A moderate thermal anomaly was detected on the Alaid volcano from 00:39 UTC on September 15 (36 and 23 MW recorded by Mirova), and it continues to be noted until now. KVERT considers this phenomenon as the start of an explosive Strombolian eruption of the Alaid volcano. No ash cloud produced. KVERT continues monitoring.
The moderate eruptive activity of the volcano continues. Ash explosions up to 6 km a.s.l. could occur at any time. Aviation color code changed from green to yellow.

Alaid - the island-volcano, the northernmost of the Kuril archipelago, is located 30 km northwest of Paramushir and 70 km southwest of Kamchatka. Alaid exposes a high potential danger for planes flying over Kamchatka and the Northern Kuriles.

Its last eruption dates back to 2018.

 

Sources : KVERT 16.09.2022 / 10:42Z, Mirova, and Global Volcanism Program

Merapi - activity report from 09 to 15.09.2022 - Doc. BPPTKG

Merapi - activity report from 09 to 15.09.2022 - Doc. BPPTKG

This week from September 9 to September 15, 2022, 13 lava avalanches were observed southwest of the Merapi, dominant up to the Bebeng River with a maximum slip distance of 1,800 m.

In the southwest dome, there is no change in the height of the dome. For the middle dome, no significant morphological change was observed. Based on photo analysis, the volume of the southwest dome is calculated to remain at 1,624,000 m, and for the central dome, it is 2,772,000 m.

The observatory recorded 429 deep volcanic earthquakes (VTA), 71 shallow volcanic earthquakes (VTB), 516 multiphase earthquakes (MP), 1 low frequency earthquake (LF), 426 tremors aborted earthquakes (RF), 37 Blowing earthquakes (DG), 15 times Tectonic earthquake (TT).

Mount Merapi's deformation, which was monitored using EDM this week, showed a distance shortening rate of 0.7 cm/day.

Merapi - seismicity and deformation from 09 to 15.09.2022 - Doc. BPPTKG

Merapi's volcanic activity is still quite high in the form of effusive eruption activity. The state of the activity is defined at the Siaga level

The current potential danger is in the form of lava avalanches and hot clouds in the south-southwest sector covering the Boyong River for a maximum of 5 km, Bedog River, Krasak, Bebeng for a maximum of 7 km . The southeastern sector covers the Woro River for a maximum of 3 km and the Gendol River for a maximum of 5 km. Meanwhile, the ejection of volcanic material in the event of an explosive eruption can reach a radius of 3 km from the summit.

 

Source: BPPTKG

Trident, seen here from Baked Mountain to its NW, was originally named for its three prominent peaks. A series of eruptions from 1953 to 1968 built a fourth cone, which forms the smoothest peak to the right. No less than 23 lava domes are found in the Trident Volcanic Complex. The 1912 Novarupta lava dome is visible in the lower center. Photo by Game McGimsey (U.S. Geological Survey, Alaska Volcano Observatory) via AVO - one click to enlarge

Trident, seen here from Baked Mountain to its NW, was originally named for its three prominent peaks. A series of eruptions from 1953 to 1968 built a fourth cone, which forms the smoothest peak to the right. No less than 23 lava domes are found in the Trident Volcanic Complex. The 1912 Novarupta lava dome is visible in the lower center. Photo by Game McGimsey (U.S. Geological Survey, Alaska Volcano Observatory) via AVO - one click to enlarge

A swarm of earthquakes below Trident Volcano, Alaska, began on August 24, 2022 and is continuing but now at a reduced rate. Earthquake depths at the start of the swarm were mostly deep, about 25 km (16 miles) below sea level, and gradually became shallower until about 5 km (3 miles) the August 28. Since August 28, most earthquakes have occurred at depths of 0 to 7 km (0 to 4.3 miles) below sea level. Earthquake magnitudes (M) have ranged from M –0.7 to M 1.9. At the height of the swarm, dozens of earthquakes were occurring daily beneath the volcano, and over the past week earthquake rates have declined to a few per day. A few episodes of weak seismic tremor and low frequency earthquakes also occurred. No other signs of agitation were detected in the available monitoring data.

Earthquakes located below Trident Volcano, Alaska from August 1 through September 13, 2022. The top panel shows earthquakes by day and the bottom panel shows earthquake depths over time. A swarm of relatively deep earthquakes began on August 24, with the quakes getting shallower over time. The rate of events per day remained high during the first week of September and almost returned to normal on September 13. The size of the circles in the lower panel reflect the magnitude of the earthquakes, as shown in the legend. Doc. AVO

Earthquakes located below Trident Volcano, Alaska from August 1 through September 13, 2022. The top panel shows earthquakes by day and the bottom panel shows earthquake depths over time. A swarm of relatively deep earthquakes began on August 24, with the quakes getting shallower over time. The rate of events per day remained high during the first week of September and almost returned to normal on September 13. The size of the circles in the lower panel reflect the magnitude of the earthquakes, as shown in the legend. Doc. AVO

The increase in seismic activity is probably caused by the movement of magma or magmatic fluids. Increases in seismic activity have already been detected at Trident and other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and other signs of unrest, such as gassing, elevated surface temperatures, and surface deformation, to precede any future eruption, should it occur.

Current volcano alert level: NORMAL
Current Aviation Color Code: GREEN

 

Trident is one of the Katmai Group volcanoes located in Katmai National Park and Preserve on the Alaska Peninsula. Trident consists of a complex of four cones and numerous lava domes, all composed of andesite and dacite, which reach up to 6,115 feet above sea level. An eruption beginning in 1953 built the newest cone, Southwest Trident, and four lava flows on the flank of the older complex. This eruption continued until 1974 and produced ash (an initial plume rose 30,000 feet above sea level), bombs and lava at various times. Fumaroles remain active at the summit of the southwest Trident and on the southeast flank of the oldest central cone.

 

Source: AVO

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