Report on Merapi (Indonesia) — 23 February-1 March 2022
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 23 February-1 March 2022
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2022. Report on Merapi (Indonesia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 23 February-1 March 2022. Smithsonian Institution and US Geological Survey.
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
BPPTKG reported that both of Merapi’s two lava domes, situated just below the SW rim and in the summit crater, effused lava during 18-24 February. Based on analysis of drone data the volumes of the SW and central domes were an estimated 1.58 and 3.23 million cubic meters, respectively. Seismicity remained at high levels. In the SW-flank Bebeng drainage there were as many as 173 lava avalanches that traveled a maximum of 2 km and one pyroclastic flow that extended 1.8 km. Minor ashfall was reported in the Pakem District on 18 February. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location.
Geological Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities.