Report on Merapi (Indonesia) — 18 September-24 September 2024
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 18 September-24 September 2024
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2024. Report on Merapi (Indonesia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 18 September-24 September 2024. Smithsonian Institution and US Geological Survey.
Merapi
Indonesia
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 13-19 September. Seismicity was slightly less intense compared to the previous week. The SW lava dome produced 426 lava avalanches that traveled as far as 1.9 km down the Bebeng drainage on the SW flank. Nine pyroclastic flows descended the Bebeng as far as 1.3 km. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 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.
Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)