Indonesian authorities warn against climbing Mount Merapi due to explosive eruption risk

Indonesian authorities are reiterating a strict prohibition on climbing Mount Merapi, citing the persistent danger of explosive eruptions. The Center for Volcanology and Geological Hazard Mitigation (BPPTKG) stressed that climber safety must be the top priority, as volcanic material could be ejected up to 3 kilometers from the summit. This range encompasses areas previously used for climbing routes and final boundaries, placing anyone in the vicinity at high risk. Agus Budi, head of BPPTKG, urged the public and climbers to understand the current dynamics of Merapi's activity. While the volcano is in an effusive phase, characterized by slow magma extrusion, this does not eliminate the threat. Budi warned that the potential for sudden explosive eruptions remains high if the magma's exit path becomes blocked. Such blockages can lead to a significant buildup of gas pressure within the crater, ultimately resulting in a sudden, explosive release of energy. Historical data supports this caution, as Mount Merapi has exhibited five different eruption types over the past three centuries, with explosive eruptions being the most common. Since 2010 alone, 32 explosive eruptions have been recorded, predominantly of the phreatic type. Consequently, the closure of climbing activities in potential hazard zones is considered the primary mitigation measure and must be adhered to. The Mount Merapi National Park Center (TNGM) has also confirmed that climbing routes remain closed, a measure in place since May 22, 2018, when the volcano's status was raised to Level II (Alert). The status was further elevated to Level III (Siaga) on November 5, 2020, and remains at that level.