During 9-22 December, low-level ash plumes were continuously emitted from Papandayan's Baru crater. On 12 December at 1758 an explosion occurred, causing stepped landslides on the wall of Nangkak crater. Small lahars traveled down Cibeureum Gede and Ciparugpug rivers on 13 December at 1600 and on 14 December at 1700. On 21 December at 1154 stepped landslides occurred again. Papandayan remained at Alert Level 3 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Geological Summary. Papandayan is a complex stratovolcano at the S end of a curved volcanic massif with Kendang volcano ~9 km away at the N end, Gunung Puntang ~3.5 km NNE, and Gunung Jaya ~6 km NNE. Several episodes of collapse have created an irregular profile and produced debris avalanches that have affected lowland areas. The summit area includes four large craters, including the 1.1-km-wide, flat-floored Alun-Alun crater. A sulfur-encrusted fumarole field occupies the active Kawah Mas ("Golden Crater"). The first reported eruption, in 1772 CE, included a collapse of the NE flank and a debris avalanche that destroyed 40 villages and killed almost 3,000 people. Smaller phreatic eruptions occurred during 1923-25, 1942, and 2002.