The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki. During 14-20 February the seismic network recorded decreasing seismicity, specifically there was a notable decrease in both deep and shallow volcanic earthquakes, though signals indicating emissions continued to fluctuate. Fumarolic plumes rose from cracks on the upper NW flank and eruptive events producing ash plumes were recorded on 17 February. The exclusion zone was reduced to a radius of 6 km in all directions from the center of Laki-laki. At 1200 on 20 February the Alert Level was lowered to 3 (on a scale of 1-4) and the exclusion zone was again reduced, to 5 km from the center of Laki-laki and 6 km in a semicircle counterclockwise from the NE to the SW. Several eruptive events per day during 21-22 and 24 February, and one event on 23 February, generated ash plumes that rose 0.4-2 km above the summit and drifted in different directions. Incandescence at the summit and reflected in the plume was visible in several of the webcam images posted with the reports.

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)