The volcano produced three pyroclastic flows at 09:01, 09:30 and 15:42 local time today reaching length of at least 4500 meters from the summit.
Block-and-ash flows created billowing ash plumes separating from the pyroclastic density currents (so-called phoenix clouds).
Based on this event, the volcanologists raised the alert level to Level 3.
The volcano observatory reported seismic signals with maximum amplitudes of 25, 17 and 20 mm and a duration of 395 and 400 seconds.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi volcano activity update 16 December 2021
Pyroclastic flow traveled over the upper slopes (source: @ronitoxid/twitter)
dapet laporan dari kawan yg jadi relawan di #Semeru, hari ini Semeru kembali bergetar dan ada lahar dingin dan erupsi ternyata belum berhentimohon doanya kawan, untuk para relawan yg masih berusaha melakukan evakuasi di sanamohon doanya, sungguh sungguh pic.twitter.com/32l22YtLqo
— ronitoxid paranoid (@ronitoxid) December 16, 2021