Agung volcano news & activity updates:
Agung volcano (Bali, Indonesia): sudden new explosion early this morning leads to ash fall, but no major eruption expected
Sunday Dec 30, 2018 13:22 PM | BY: T
The volcano erupted again early this morning (30 Dec 2018) at 04:09 local time. A moderately sized sudden explosion lasted for 3 minutes 8 seconds, caused by accumulated overpressure of gasses inside and under the lava plug that had formed on top of the conduit by the magma erupted in the 2017-18 eruption.
Eruption of Gunung Agung volcano on Bali this morning (image: VSI)
The Indonesian Volcanological Survey reported that "fire" (i.e. incandescence) was observed in the summit area of the crater, but the height of the ash column was not observed due to fog. Based on satellite data, a plume rose to approx. 18,000 ft (5.5 km) and drifted southeast. Light ash fall was noticed in the Karangasem Regency in the southeast sector of Mount Agung, such as in Amlapura City and several other villages such as Seraya Barat, Seraya Tengah, and Tenggalinggah Village.
Before this eruption, no significant increase in intensity of seismicity had been observed but several small volcanic earthquakes had been recorded. These included a M2.7 event on the northern slope of Mount Agung on 28 December 2018 at 2:49 WITA and a M2.4 quake at 15: 31 WITA. These earthquakes indicated the movement of magma to the surface, which means that the eruptive phase of Agung is not really over.
In the period of 27-29 December 2018, no thermal anomalies were detected on the surface by satellite monitoring, meaning that no new lava has so far arrived there.
The last previous eruption of Gunung Agung was on July 27, 2018. On July 29, 2018 at 06:47 WITA, the Lombok Earthquake with Magnitude M6.4 occurred and was accompanied by several aftershocks. These tectonic earthquakes around the island of Lombok probably affected the activity of Mount Agung as well, in that the shaking favored in the release of volcanic gases from cooling magma in the conduit, which in turn led to increased degassing and a decreased potential of explosions. As the rate and intensity of earthquakes of nearby tectonic origin had decreased over the past months, gasses were more likely to remain trapped and their slow release from the cooling magma helped building up towards this morning's explosion.
According to VSI, based on overall data analysis, the potential for a larger eruption in the near future remains relatively small, although smaller eruptions could occur at this time and eject incandescent rock / lava material, cause ash rain or gusts of volcanic gases.
The alert status of Mount Agung is still kept at Level III (Siaga, "Alert") with a safety zone recommended in a 4 km radius around the crater of the volcano. Significant secondary hazards remain in the form of lahars (mud flows) caused by rapid remobilization of loose volcanic material during heavy rains.
Links / Sources:
Links / Sources:
Saturday, Dec 29, 2018
Thursday, Aug 16, 2018
Wednesday, Aug 08, 2018
Sunday, Jul 29, 2018
Wednesday, Jul 25, 2018
Hazard map of Agung volcano (Sep 2017)
Hazard map of Agung volcano (PVMBG)