Indonesia: Eruption earthquakes still dominate the activity of Mount Semeru in Lumajang

Lumajang, East Java - Eruption earthquakes still dominate the activity of Mount Semeru which has a height of 3,676 meters above sea level (masl) located in Lumajang Regency, East Java.

"In the earthquake observation period Thursday (4/7) at 00.00-24.00 WIB, Semeru was recorded to have experienced 159 eruption earthquakes with an amplitude of 10-22 mm, and an earthquake duration of 55-132 seconds," said Mount Semeru Observation Post Officer, Mukdas Sofian in a written statement received in Lumajang, Friday.

According to him, the mountain located on the border of Lumajang Regency and Malang experienced 12 avalanche earthquakes with an amplitude of 2-8 mm and an earthquake duration of 32-78 seconds.

"In addition, it was also recorded that there were 12 gust earthquakes with an amplitude of 3-8 mm, and an earthquake duration of 28-74 seconds, then six distant tectonic earthquakes with an amplitude of 16-40 mm," he said.

Flood vibration earthquakes were also recorded on Mount Semeru with an amplitude of 10 mm and an earthquake duration of 2,026 seconds because heavy rain poured on the peak of the highest mountain on Java Island.

Meanwhile, the Head of the Center for Volcanology and Geological Disaster Mitigation (PVMBG) Hendra Gunawan said that officers were evaluating the activity of Mount Semeru in stages.

"Based on the results of a comprehensive analysis and evaluation until June 30, 2024, the activity level of Mount Semeru remains at level III or alert with recommendations adjusted to the current threat of danger," he said.

He said that his party recommended that the public not carry out any activities in the southeast sector along Besuk Kobokan as far as 13 kilometers from the peak (center of the eruption).

Then outside that distance, he said, the public is also advised not to carry out activities within 500 meters of the river bank (river boundary) along Besuk Kobokan, because it has the potential to be hit by the expansion of hot clouds and lava flows up to a distance of 17 km from the peak.

Then residents are also prohibited from carrying out activities within a five-kilometer radius of the crater/peak of Mount Semeru, because it is prone to the danger of ejected rocks (incandescent).

public is also asked to be aware of the potential for hot clouds, lava avalanches, and lava, along the river/valley that originates at the peak of Mount Semeru, especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lava in small rivers that are tributaries of Besuk Kobokan.