The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki during 4-10 December. The maximum heights of white-and-gray plumes decreased during the first part of the week, rising to 1.5 km, 1.2 km, and 500 m above the summit on 4, 5, and 6 December, respectively. The plumes drifted in multiple directions. On 6 December the exclusion zone was modified, prohibiting entry within a radius of 6 km from the center of Laki-laki and 7 km in a semicircle counterclockwise from the NE to the SW. White plumes rose 100-300 m above the summit and drifted W and NW on 7 and 10 December; no emissions were visible during 8-9 December. White-and-gray ash plumes rose as high as 2 km above the summit and drifted SW and W on 10 December. The Alert Level remained at 4 (on a scale of 1-4).

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)