Lumajang, E Java (ANTARA) – Mount Semeru on the border of East Java’s Lumajang and Malang Districts recorded 21 eruption earthquakes in six hours on Friday (August 28), according to Semeru monitoring post officer Yadi Yuliandi.
The earthquakes, recorded from midnight to 6 a.m. local time, had amplitudes of 10-22 mm and lasted between 67 and 120 seconds, he said in a written statement received here Friday morning.
Semeru also recorded two rockfall earthquakes, two emission earthquakes and two distant tectonic earthquakes. The events had amplitudes of 2-12 mm, 6-8 mm and 5-17 mm, respectively.
“The volcano was clearly visible, while no crater smoke was observed. The weather was clear, with light winds blowing southeast and south,” Yadi said.
Semeru is currently at Level III, or Alert, with authorities advising residents against activities in the southeast sector along Besuk Kobokan, extending 13 km from the summit.
Beyond that zone, residents should stay at least 500 meters from the riverbanks along Besuk Kobokan because hot clouds and lahars could travel up to 17 km from the summit.
Residents are also prohibited from activities within five km of Semeru’s crater or summit because of the risk of incandescent rockfall.
Authorities urged residents to remain alert for hot clouds, lava avalanches and lahars along rivers and valleys originating from Semeru’s summit.
The warning particularly covers Besuk Kobokan, Besuk Bang, Besuk Kembar and Besuk Sat, as well as smaller tributaries flowing into Besuk Kobokan, Yadi said.
Meanwhile, Bromo Tengger Semeru National Park has fully closed the Semeru hiking route since August 26 after a forest fire broke out in the Ranu Kembang Block.
All hikers in the area had descended by Thursday (August 27), according to the park authority.
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Translator: Zumrotun S, Rahmad Nasution
Editor: Primayanti
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