Dempo News

 

A explosion occurred yesterday morning inside the summit crater of the volcano. At 9.05 a.m. local time, dense jets of light to dark-gray ash and rocks, mixed with white steam, were ejected in a sudden, violent blast from the crater. The ash plume, also seen from people near the base of the volcano, rose a few hundred meters and quickly dissipated after the end of the eruption.

Climbers who were on the crater rim at the time filmed the event and could escape unharmed:

lekas sembuh dempo pic.twitter.com/M3J2G2S3Fm

 According to information from the Indonesian volcanological survey BVMBG, the eruption was likely phreatic in origin, i.e. entirely driven by steam explosion without ejecting fresh magma, which fits the visual style of the eruption, typical for such dangerous, and usually unpredictable explosions. The corresponding seismic signal had a maximum amplitude of 35 mm and lasted for 182 seconds.

The volcano started to show new signs of activity last year already; seismic unrest had been observed in January 2022 and the alert status had been raised. In May 2022, a similar phreatic eruption occurred. More than a year later, a series of small eruptions occurred a month ago in July 2023, producing ash plumes that rose up to 2 km. On 25 July 2023, scientists recorded again increased seismic activity.
A possible scenario is that new magma, so far not seen at the surface, is intruding / rising inside the volcano and could lead to a new, potentially vigorous eruption involving magma proper. Dempo is one of Sumatra's most active volcanoes with at least 28 documented eruptions over the past 200 years, although none of its historic eruptions was large.