PVMBG reported that during 29 July-4 August the lava-dome volume at Merapi did not change and was an estimated 475,000 cubic meters, based on analyses of drone images. Extruded lava fell into the upper parts of the SE-flank, generating a total of four block-and-ash flows that traveled as far as 1 km down the Gendol drainage on 31 July and 4 August. Diffuse white plumes rose as high as 50 m above the summit on some days. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to stay outside of the 3-km exclusion zone.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)