Urgent Need of Submarine Landslide Risk Monitoring after 2025 Mega-quake off Coast of Kamchatka

Deep-origin earthquakes can induce creep and progressive weakening of shallow marine sediments, potentially leading to large-scale submarine landslides that may trigger destructive tsunamis. Following the Mw 8.8 Kamchatka Peninsula earthquake on July 30, 2025, which prompted Pacific-wide tsunami alerts and evacuations, its cascading effects persist while full consequences remain unassessed. This study integrates a global submarine landslide susceptibility database with multi-source datasets to evaluate post-seismic seafloor sliding risk. We employ an ensemble machine learning model that performs weighted averaging of predictions from Random Forest, XGBoost, LightGBM, and CatBoost algorithms. Results indicate the 2025 mega-earthquake significantly amplified sliding hazards. Areas classified with very high landslide susceptibility (index >0.8) cover approximately 96,000 km², highlighting an urgent need to monitor ongoing sediment creep, landslide dynamics, and associated secondary tsunami risks in the region. The high-risk zones exhibit an asymmetric, patchy distribution, controlled jointly by regional tectonic setting (the Kuril-Kamchatka Trench) and sediment properties (e.g., lithology, roughness). These findings provide new insights for modeling multi-hazard chains linking deep-focus earthquakes, sediment deformation, slope failure, and tsunami generation, with implications for hazard early-warning and mitigation strategies across the Pacific.