EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Precursors and processes culminating in the Anak Krakatau December 2018 sector collapse and tsunami

Thomas R. Walter1 and the Rapid Response Team*
Thomas R. Walter and the Rapid Response Team
  • 1GFZ Potsdam, Geophysics, Potsdam, Germany (
  • *A full list of authors appears at the end of the abstract

It is 135 years after the 1883 volcano-triggered tsunami disaster, when Krakatau volcano became once more the source of a deadly tsunami striking without warning. We use data recorded on the ground and by satellite, to show that the volcano was in an elevated stage of activity throughout the year 2018, producing thermal anomalies associated with volcanic deposits, an increase of the island area and ground movement of the southwestern sector of the island towards the sea, increasing in June 2018. Following further intense activity on 22 December 2018, seismic data reveal the timing and duration when this sector collapsed. The landslide removed 102 million m³ of material subaerially, which was followed by ~15 minutes of phreatic explosions. This study allows better understanding of the complex hazard cascades, including precursory thermal anomalies, island growth and deformation, followed by sector collapse, tsunami waves, and finally explosive volcanic eruptions, and has important implications for designing early warning systems.

Rapid Response Team:

Thomas R. Walter (1), Mahmud Haghshenas Haghighi (1,2), Felix M. Schneider (1), Diego Coppola (3), Mahdi Motagh (1,2), Joachim Saul, Andrey Babeyko, Torsten Dahm; Valentin R. Troll; Frederik Tilmann, Sebastian Heimann; Sébastien Valade; Rahmat Triyono; Rokhis Khomarudin; Nugraha Kartadinata; Marco Laiolo; Francesco Massimetti; Peter Gaebler

How to cite: Walter, T. R. and the Rapid Response Team: Precursors and processes culminating in the Anak Krakatau December 2018 sector collapse and tsunami , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2602,, 2020


Display file