The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki during 11-17 December. White-and-gray ash plumes that were sometimes dense rose as high as 800 m above the summit and drifted in multiple directions during 11 and 13-14 December. White plumes rose as high as 700 m above the summit and drifted N, NW, W, and SW on 12 and 16 December. Eruptive events were recorded on 15 December, though weather conditions prevented visual confirmation. The Alert Level remained at 4 (on a scale of 1-4) and the public was warned to stay 6 km away from the center of Laki-laki and 7 km in a semicircle counterclockwise from the NE to the SW.

Geological Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan.

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