Mount Semeru's Alert Status Raised; Update on Indonesian Volcano Activity (Monday, December 5, 2022)

Mount Semeru in Lumajang, East Java, erupted in the early hours of Sunday, December 4th. The continuous increase in activity throughout the day caused Mount Semeru's alert status to be raised from Level III (Siaga/Alert) to Level IV (Awas/Warning) by Monday, December 5th, 2022, according to data from Magma Indonesia.

Based on seismic observations, there were 29 eruption quakes with amplitudes of 11-22 mm and durations of 65-120 seconds. There was also one pyroclastic flow quake with an amplitude of 25 mm and a duration of 386 seconds. A total of 6 guguran (rockfall) quakes, 1 volcanic quake, and 1 tectonic quake were recorded at Mount Semeru.

Magma Indonesia recommends that people avoid any activity in the southeastern sector along the Besuk Kobokan river, up to 17 km from the summit (the eruption center).

"Beyond that distance, people should not engage in activities within 500 meters of the riverbanks along the Besuk Kobokan river, as there is a potential for pyroclastic flow expansion and lahars extending up to 19 km from the summit," according to the Magma Indonesia website on Monday, December 5th.

Meanwhile, three active volcanoes in Indonesia are currently at Level III (Siaga/Alert), meaning they could erupt.

These volcanoes are Mount Merapi in Yogyakarta/Central Java, Mount Ili Lewotolok in East Nusa Tenggara, and Mount Anak Krakatau in Lampung.

Furthermore, 17 active volcanoes in Indonesia are at Level II (Waspada/Watch), including Mount Awu and Mount Soputan in North Sulawesi.

Meanwhile, 47 active volcanoes in Indonesia are at Level I (Normal), including Mount Agung in Bali, Mount Ciremai in West Java, and Mount Wurlali in Maluku.

Magma Indonesia notes that there are currently 127 active volcanoes in the country. However, only 68 active volcanoes are monitored by the Center for Volcanology and Geological Hazard Mitigation (PVMBG).