|Event:|| VO Volcano|
|Country:|| IDN Indonesia|
|Date (YMD):|| 2021-12-4|
|Information Source:||The Indonesian Red Cross Society (PMI), Centre of Volcanic and Geology Disaster Mitigation (PVMBG)|
|Comments:|| On Saturday, 4 December 2021 at 14.50 Western Indonesia Time (Waktu Indonesia Barat – WIB (GMT+7)), Mount Semeru Observation Post at Gunung Sawur Post reported flood lava vibrations or hot cloud avalanches of Mount Semeru, located on the border of Lumajang and Malang districts in East Java Province. The avalanches recorded with maximum amplitude of 20 millimetres – 25 millimetres Seismographs for 5160 seconds. Hot and volcanic ashes blown towards Southwest from the crater. Mount Semeru was at alert level 2 (advisory, waspada) prior to the lava vibrations and still remains at level 2. As of 9 December 2021, Centre of Volcanic and Geology Disaster Mitigation or Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), reported 9 eruptions following the main eruption on Saturday with maximum amplitude ranging from 22-37 mm, occurring between 200-240 seconds.
As of 9 December 2021, 3 districts in East Java Province namely Lumajang district, Malang district and Blitar district have been affected by the hot ash and lava avalanches.|