Landslide, Not Sinkhole, Caused Massive Hole in Central Aceh, Indonesia

Jakarta, Indonesia – February 21, 2026 – A large cavity that appeared in Pondok Balik Village, Ketol Subdistrict, Central Aceh Regency, Aceh Province, Indonesia, is the result of a landslide, not a sinkhole, according to Indonesia’s National Research and Innovation Agency (BRIN). The affected area spans more than 30,000 square meters and reaches a depth of up to 100 meters, disrupting access between subdistricts and damaging local plantations.

What Caused the Landslide?

BRIN’s Geological Disaster Research Center, led by Adrin Tohari, determined that the area’s geological composition contributed to the landslide. The land is comprised of a layer of tuff – volcanic ash that has solidified – which is not dense and has low strength, making it easily eroded and prone to collapse. Antara News reports that satellite imagery dating back to 2010 already showed a small valley or canyon at the site, indicating a pre-existing vulnerability.

Over time, erosion and repeated landslides widened and deepened this area, ultimately forming the large cavity observed today. Contributing factors include a 6.2-magnitude earthquake that struck Central Aceh in 2013, which likely weakened the slope structure, and heavy rainfall that saturated the fragile tuff rock, reducing its cohesion. Surface water from plantation irrigation channels too increased water infiltration, exacerbating the instability.

Historical Context and Geological Factors

The area’s geological characteristics are similar to those found in Sianok Canyon in West Sumatra, which was formed through a long geological process related to tectonic activity. VOI notes that the Ketol area does not consist of limestone, which is typically associated with sinkhole formation.

Ongoing Analysis and Future Mitigation

BRIN is currently analyzing image data and public information to gain a more detailed understanding of the event. Although direct field research has not yet been conducted, the agency plans to update ground movement vulnerability maps to improve accuracy and operational effectiveness. DetikNews reports that BRIN recommends increased vigilance for early warning signs, such as ground cracks or small subsidence.

Key Takeaways

• The large hole in Central Aceh was caused by a landslide, not a sinkhole.
• The area’s tuff layer is weak and easily eroded.
• A 2013 earthquake and heavy rainfall contributed to the landslide.
• BRIN is analyzing the situation and plans to update vulnerability maps.