From slow deformation to rapid mass movements: investigating detachment mechanism, runout, and process chains in the Austrian Alps using remote sensing (satellite data, RS, and GIS) and conventional methods.

Austria is highly exposed to complex gravitational processes, including rockfalls, rockslides, rock avalanches, and landslides, driven by steep alpine topography, heterogeneous lithology, and strong hydro-meteorological forcing. While satellite radar interferometry is well established for detecting and monitoring slow-moving slope instabilities, a major challenge remains the understanding and anticipation of failure mechanisms that lead to rapid mass movements and cascading process chains with long runout distances.

Many catastrophic events are preceded by slow deformation phases and evolve through a combination of rock mass detachment, rock avalanche propagation, and subsequent transformation into rapid flow-like landslides when interacting with saturated soils, specific soil types, or glacial and periglacial environments. These coupled processes are not widely studied due to limitations in space and time, which limit the effectiveness of current hazard assessment and early warning strategies.

This contribution presents a conceptual and methodological framework that examines SAR time series and Copernicus European Ground Motion Service (EGMS) products to study failure mechanisms and process transitions in alpine terrain. EGMS serves as a baseline for identifying millimeter-scale precursory ground deformations linked to slow-moving instabilities, rock mass creep, and potential detachment zones. Deformation signals are combined with topographic, geological, and geomorphological data, as well as hydro-meteorological indicators such as precipitation, snowmelt, soil moisture proxies, and glacier presence, to evaluate conditions that could promote rapid failure and runout amplification. Plus, the use of simple process models for runout estimation.

Instead of focusing only on deformation detection, the proposed approach aims to connect observed ground motion patterns with environmental factors that influence detachment, mobility, flow transformation, and their reach. The framework supports analyses at multiple scales, from national screening to detailed studies of specific processes affecting infrastructure and settlements. Designed as a foundation for future PhD research on EO-based monitoring, failure mechanisms, and early warning of complex mass movement processes.