PVMBG reported that eruptive activity at Lewotobi’s Laki-laki volcano continued during 11-17 September from a vent on the upper NW flank. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1 km above the summit and drifted SW, W, and NW. The Alert Level remained at 3 (the second highest level on a scale of 1-4) and the public was warned to stay outside of the exclusion zone, defined as a 3 km radius around both Laki-laki and Perempuan craters, 4 km to the NNW and SSE of Laki-laki.

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)