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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 Anak Krakatau, three exolosive episodes occurred on July 18, 2022, according to Magma Indonesia.

The first at 08:26 WIB, accompanied by emission of gas and gray to black ash, observed at ± 2000 m above the summit (± 2157 m above sea level) dissipating towards the southwest. This eruption was recorded on a seismograph with a maximum amplitude of 53 mm and a duration of 127 seconds.

Anak Krakatau - 18.07.2022 / 08:27 - PVMBG / Magma Indonesia webcam - one click to enlarge

Anak Krakatau - 18.07.2022 / 08:27 - PVMBG / Magma Indonesia webcam - one click to enlarge

The second occurred at 3:49 p.m. WIB with a column of gray ash observed ± 2500 m above the summit (± 2657 m above sea level). This eruption was recorded on a seismograph with a maximum amplitude of 55 mm and a duration of 97 seconds.

Anak Krakatau - 18.07.2022 / 3:50 p.m. WIB - - PVMBG / Magma Indonesia webcam - one click to enlarge

Anak Krakatau - 18.07.2022 / 3:50 p.m. WIB - - PVMBG / Magma Indonesia webcam - one click to enlarge

The third occurred at 5:30 p.m. WIB accompanied by a gray ash plume observed ±2500 m above the summit (±2657 m above sea level) to the southwest. This eruption was recorded on a seismograph with a maximum amplitude of 55 mm and a duration of 73 seconds.

Anak Krakatau - 18.07.2022 / 5:31 p.m. WIB - - PVMBG / Magma Indonesia webcam - one click to enlarge

Anak Krakatau - 18.07.2022 / 5:31 p.m. WIB - - PVMBG / Magma Indonesia webcam - one click to enlarge

Seismicity is further marked by:
- 5 blast / emission earthquakes, with an amplitude of 9 to 48 mm and the duration of the earthquake was 25 to 70 seconds.
- 9 harmonic episodes, with an amplitude of 11-17 mm and an earthquake duration of 10-37 seconds.
- 12 low frequency earthquakes, with an amplitude of 2 to 36 mm and the duration of the earthquake is 5 to 15 seconds.
- 12 shallow volcanic earthquakes, with an amplitude of 4-34 mm and an earthquake duration of 5-20 seconds.
- 1 deep volcanic earthquake, with an amplitude of 49 mm, S-P 3.6 seconds and an earthquake duration of 25 seconds.
- 4 episodes of continuous tremor, with an amplitude of 0.5 to 31 mm, dominating 5 mm.

 

The NOAA-20 and Sentinel-2 satellites spotted a thermal anomaly in the crater.

 

The activity level remains at 3 / siaga, with the recommendation for
communities/visitors/tourists/climbers not to approach Krakatau, nor engage in activities within 5 km of the active crater.

 

Sources: PVMBG, Magma Indonesia, VAAC Darwin, Sentinel-2

Anak Krakatau - thermal anomaly - image Sentinel-2 bands 12,11,8A dated 07.18.2022 / 02:55 - via Mounts Project - click to enlarge

Anak Krakatau - thermal anomaly - image Sentinel-2 bands 12,11,8A dated 07.18.2022 / 02:55 - via Mounts Project - click to enlarge

Anak Krakatau - thermal anomalies on 18.07.2022 - Doc. Mirova _MODIS_Latest10NTI

Anak Krakatau - thermal anomalies on 18.07.2022 - Doc. Mirova _MODIS_Latest10NTI

Anak Krakatau - incandescence on 07.18.2022 / 11:52 p.m. WIB - PVMBG / Magma Indonesia webcam - one click to enlarge

Anak Krakatau - incandescence on 07.18.2022 / 11:52 p.m. WIB - PVMBG / Magma Indonesia webcam - one click to enlarge

The growth of the lava dome continues at Sheveluch (summit altitude: 3,283 m., dome altitude: ~2,500 m.), strong fumarolic activity and incandescence of the lava dome, explosions and hot avalanches accompany this process. Video and satellite data from KVERT showed a plume of resuspended ash up to 3.5 km a.s.l. extending to the east-southeast of the volcano.

The extrusive eruption of the volcano continues. Ash explosions up to 10-15 km (32,800-49,200 ft) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.

The color of the aviation code remains orange.

 

Source: KVERT

Sheveluch - photo archive Volkstat.ru - one click to enlarge

Sheveluch - photo archive Volkstat.ru - one click to enlarge

The I.G.Peru reports, for the week of July 11 to 17, a moderate eruptive activity at Sabancaya, with an average of 28 daily explosions, accompanied by plumes of gas and ash reaching up to 2,700 meters above the summit.

During this period, 260 earthquakes associated with the circulation of internal magmatic fluids and VT earthquakes, linked to rock fracturing, were recorded.

No significant deformation anomaly; 8 thermal anomalies are identified, of max. of 15 MW, in connection with the presence of a lava dome in the crater.

The volcanic alert remains in naranja, with a non-accessible zone of 12 km radius.

 

Source: I.G.Peru

Sabancaya - activity from 11 to 17.07.2022 - Doc. I.G.P.

Sabancaya - activity from 11 to 17.07.2022 - Doc. I.G.P.

Sabancaya - thermal anomalies as of 19.07.2022 / 02h45 - Doc. Mirova _MODIS_logVRP

Sabancaya - thermal anomalies as of 19.07.2022 / 02h45 - Doc. Mirova _MODIS_logVRP

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