Anak Krakatau Erupts, Geological Agency Reminds To Keep 2 Km Distance From Crater

Mount Anak Krakatau (Photo: Antara)

JAKARTA - Head of the Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) Eko Budi Lelono appealed to the public not to approach Mount Anak Krakatu within a radius of 2 kilometers (km) from the active crater.

Based on observations, the eruption at Mount Anak Krakatau occurred 9 times with the height of the ash column ranging from 800-1000 meters above the peak and the color of the column was thick gray-black.

"In connection with the activity level of Mount Anak Krakatau being at Level II (Alert), we recommend that people are not allowed to approach Mount Krakatau within a radius of 2 km from the Active Crater," said Eko in his statement quoted on Saturday, February 5.

In this eruption phase, a transition from a white gust of smoke was observed to a gust and an eruption of gray to jet black ash. Visual monitoring indicated that the eruption was magmatic type, in line with recorded volcanic earthquakes.

He described, visually, the height of the puff of smoke during the period January 16 - February 4 2022 from the direction of the Pasauran and Kalianda PGA Posts and from CCTV generally it could not be observed because the mountains were generally covered in fog.

Meanwhile, when the weather was clear, the crater smoke gusts during the evaluation period were observed to be thin and thick white continuously with a height of 25 - 1000 meters from the top of Mount Anak Krakatau, dominantly inclined to be blown by the wind to the north, northeast, east and south.

"On February 3, 2022, an increase in the intensity of the gust of smoke to ash was observed and at night the rays of fire were observed above the crater," said Eko.

Meanwhile, the seismicity of Mount Anak Krakatau during January 16 - February 4 2022 was marked by the recording of 9 earthquakes with eruptions, 135 gusts of earthquakes, 4 times of harmonic tremors, 499 times of low frequency earthquakes, 2 times of hybrid/multi-phase earthquakes, and 32 times of volcanic earthquakes. shallow, 4 times deep volcanic earthquakes, 2 times local tectonic earthquakes, 8 times distant tectonic earthquakes and 19 times continuous tremor earthquakes with an amplitude of 0.5-26 mm (dominantly 5 mm).

In the February 2022 eruption period, an increase in magmatic intrusion may begin to occur since December 20, 2021, which is indicated by the significant number of deep volcanic and shallow volcanic earthquakes recorded. In January 2022, high volcanic earthquakes were still observed and more and more shallow earthquakes were recorded.

At the end of January 2021, it was indicated that magma was at a very shallow depth and ash emissions had been observed since February 3, 2022 at around 10:00 WIB. On February 4, 2022, 9 earthquake eruptions were recorded, namely at 09:43, 10:25, 10:28, 12:46, 13:00, 13:31, 13:41, 14:46 and 17:07 WIB.

Furthermore, Eko also explained that the energy of volcanic activity as reflected in the RSAM (real-time seismic amplitude measurement) value showed a fluctuating pattern with a relatively increasing trend in the period January - February 2022.

This increase is associated with an increase in gusts, low frequency, and continuous tremors which have relatively increased energy in both the number and magnitude of the earthquake amplitudes caused by the release of energy that occurs when the fluid flows to the surface.

"Monitoring of tiltmeter deformation indicates a pattern of leverage during this period caused by changes in surface pressure associated with magma fluid movement to the surface. Visual and instrumental monitoring data indicate that Mount Anak Krakatau still has the potential to erupt," concluded Eko.