Mount Semeru erupts six times, with eruption column reaching 1,000 metres

Mount Semeru, located on the border of Lumajang and Malang Regencies in East Java, recorded six eruptions with column heights reaching up to 1,000 metres above the peak on Thursday between 00:41 and 11:13 WIB. The first eruption occurred at 00:41 WIB, with an observed column height of approximately 600 metres above the peak. The ash column was observed to be white to grey with moderate intensity, drifting southwest. The eruption was still ongoing at the time the report was made. The highest eruption, according to Mount Semeru Observation Post Officer Sigit Rian Alfian in a written report, occurred at 08:03 WIB, with the column height reaching 1,000 metres above the peak, or 4,676 metres above sea level. The thick ash column, white to grey in colour, was observed moving southwest. That eruption was recorded on a seismograph with a maximum amplitude of 22 mm and a duration of 94 seconds. Seismic observation of Mount Semeru over the last six hours, from 06:00 to 12:00 WIB, recorded 18 eruption earthquakes, one avalanche earthquake with an amplitude of 3 mm, and six emission earthquakes with amplitudes of 5-7 mm. Sigit explained that Mount Semeru’s volcanic activity is currently at Alert Level III. He recommended that the public refrain from any activities in the southeast sector along Besuk Kobokan, extending 13 kilometres from the peak, or eruption centre. Beyond that distance, people should not conduct activities within 500 metres of the riverbank along Besuk Kobokan, as this area is potentially threatened by the expansion of pyroclastic flows and lava flows reaching up to 17 kilometres from the peak. The public is prohibited from engaging in activities within a five-kilometre radius of Mount Semeru’s crater or peak due to the danger of ejected incandescent rocks. He urged the public to remain vigilant for the potential of pyroclastic clouds, lava avalanches, and lahars along the river valleys or basins originating at the peak of Mount Semeru.