2019/10/01 by Thomas R. Walter, Mahmud Haghshenas Haghighi, Felix Schneider +15 · 1 citation
Earth and Planetary Sciences · #earthquake and tectonic studies #Geological and Geophysical Studies #Geological and Geochemical Analysis
paper · pdf · doi:10.1038/s41467-019-12284-5
openalex publication_date 2019/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Flank instability and sector collapses, which pose major threats, are common on volcanic islands. On 22 Dec 2018, a sector collapse event occurred at Anak Krakatau volcano in the Sunda Strait, triggering a deadly tsunami. Here we use multiparametric ground-based and space-borne data to show that prior to its collapse, the volcano exhibited an elevated state of activity, including precursory thermal anomalies, an increase in the island's surface area, and a gradual seaward motion of its southwestern flank on a dipping décollement. Two minutes after a small earthquake, seismic signals characterize the collapse of the volcano's flank at 13:55 UTC. This sector collapse decapitated the cone-shaped edifice and triggered a tsunami that caused 430 fatalities. We discuss the nature of the precursor processes underpinning the collapse that culminated in a complex hazard cascade with important implications for the early detection of potential flank instability at other volcanoes.