03.09.2026

Large earthquakes can trigger landslides that reshape mountain landscapes within minutes, yet their geomorphic legacy can unfold over millennia.

GFÚ researcher, Dr John Jansen (Surface Processes & Palaeoclimate) is co-author among an international team of researchers from China, Italy and the UK who this week published in Science Advances an important advance in understanding earthquake-triggered landslides.

The study examines the fundamental question of whether a major earthquake leaves hillslopes in a less or more stable state for earthquakes of the future. By exploiting two sequential earthquakes (2013 and 2022) at close to the same location near Lushan, China, the authors quantify how the first event preconditions hillslope failure during the second. The 2013 earthquake produced a dual effect: regional susceptibility declined as unstable material was removed, yet localized coseismic damage weakened a different population of hillslopes that later failed in 2022. These opposing outcomes can be explained by considering three different damage-recovery pathways of hillslope response that define how mass is redistributed and hillslope mechanical strength reorganizes according to a prolonged ‘hillslope memory’.

These findings have important implications for the landscape evolution of mountain belts: Hillslope response to sequential earthquakes is fundamentally path-dependent and explicitly dependent on the history of seismic shaking. The study was published 2 September and can be accessed here: https://www.science.org/doi/10.1126/sciadv.aeh3921

Since 2019, Dr Jansen has been a Distinguished Visiting Professor at the State Key Laboratory for Geohazard Prevention, Chengdu University of Technology, China. Jansen spends part of each year in Chengdu where he co-supervises PhD students and conducts research on the geomorphology of the Tibetan Plateau.

Hillslope responses and landscape adjustment under sequential earthquakes.

(A) Comparison of coseismic landslide areas that experienced equivalent peak ground acceleration (PGA) in the two earthquakes studied. (B) Three damage-recovery pathways of hillslopes subjected to repeated seismic forcing: (#1) full exhaustion and stabilization after strong shaking; (#2) delayed failure following subcritical damage; (#3) partial failure and reactivation of damaged remnants. Excess topography used in the base map quantifies the rock mass protruding above a specified critical slope angle (i.e., oversteepened hillslopes) and thus highlights zones of relief prone to landsliding.