The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported continuing activity at Lewotobi Laki-laki during 20-26 August. Dense white gas-and-steam plumes rose as high as 500 m above the summit and drifted NW, N, and NE during 20-21 August. There were 3-4 daily ash plumes during 22-23 August rising 600-1,500 m above the summit and drifting W and SW. On 23 August PVMBG noted that activity was declining after the more intense 18 August activity, based on seismic and visual monitoring data. Seismicity had declined, though low-frequency earthquakes, along with deformation data, indicated a slow rate of magma recharge at depth. Tiltmeter data was relatively stable. At 1800 the Alert Level was lowered to 3 (on a scale of 1-4) and the public was warned to stay 6 km away from the center of Laki-laki. Ash plumes continued to rose from the summit crater during 24-25 August. Ash-and-gas plumes that were mostly dense rose as high as 2 km above the crater and drifted SW and W. An eruptive event was recorded at 2024 on 25 August and at 0311 on 26 August but not observed.

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)