The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Merapi (on Java) continued during 8-14 January. The SW lava dome produced pyroclastic flows or avalanches of material that descended the flanks on most days. The seismic network detected a pyroclastic flow on 8 January. At 1548 on 9 January a pyroclastic flow traveled 1 km down the flanks though weather conditions mostly obscured views. During 10-11 January there were 5-6 daily avalanches of material that traveled as far as 2 km down the Sat/Putih drainage on the W flank. On 13 January the seismic network detected two pyroclastic flows; one occurred at 0329 and descended the flanks around 1 km. 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: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)