Marius Schneider

Rock avalanches are composed of large volumes of rapidly flowing rock fragments that can reach velocities exceeding 50 m/s and devastate extensive areas, posing a severe threat to people and infrastructure. Numerical models are essential for forecasting the associated hazards and risks; however, the runtime of most existing models limits their ability. While Deep Learning (DL) models can potentially address this limitation, the efficiency of most numerical models limits the data available for training DL. In the present work, we have overcome this limitation using the GPU-based numerical model ORIN-3D (parallel simulatOR of landslIde motioN over 3D terrain), which provides large quantities of training data for DL. We compare LinkNet and Fourier Neural Operator (FNO) for forecasting the runout of rock avalanches, which accounts for the effects of topography, initial conditions, and path materials. Utilizing ORIN-3D simulations derived from our database comprising 20 case histories and 100 synthetic cases. Both architectures demonstrate strong parameter interpolation on known terrains (especially FNO with a True Positive Rate (TPR): 96.3%, False Positive Rate (FPR): 0.7%). While cross-terrain generalization remains challenging, FNO significantly outperforms U-Net and achieves better generalization performance when temporal dimension is included in the architecture (TPR: 86.0%, FPR: 5.1%). Both architectures achieve significantly higher forecast speeds than ORIN-3D, with FNO being roughly 1000 times faster. This dramatic improvement is crucial for applications such as landslide risk analysis, where large-scale rapid forecasts are essential.

In late May 2025, a series of large rock failures from Kleines Nesthorn in the Swiss Lötschental (Lötschen valley) fell directly onto the Birchgletscher (Birch Glacier), loading the latter with around 4 million m3 of rock. On May 28, following several days of acceleration, Birchgletscher collapsed in its entirety, claiming one life and causing the near-total destruction of the historic village of Blatten (which at this point was completely evacuated). Totaling more than 9 million m3 of rock and glacier ice (with a ratio of about 3:1), the rock-ice avalanche dammed the river Lonza and led to the formation of a lake that damaged additional parts of the village.To reconstruct and understand the physical processes that controlled this remarkable hazard cascade, we used aerial topographic surveys, radar and time-lapse images, direct field observations, eyewitness accounts, meteorological data, and numerical modeling. From these data we 1) determined the precise chronology of the event, including the failure and deposition volumes and geomorphologic event traces; 2) reconstructed the pre-event (1946-2023) history of Kleines Nesthorn and Birchgletscher, including the substantial mass loss of the latter and its recent surge-type acceleration; 3) analyzed the kinematics of the rock instability on Kleines Nesthorn and the resulting rock failures that loaded the glacier; 4) used the 3-D finite element model Elmer/Ice to reconstruct the effect of the rock loading on the force balance of Birchgletscher and its relevance for the observed acceleration and collapse; and 5) processed data from several long-term weather stations, satellite data and climate models to evaluate the relevance of human-caused climate change on Birchgletscher, snow-cover, permafrost and the entire process chain. Our results highlight the complexity of the Nesthorn-Birchgletscher hazard cascade and provide valuable insights for the assessment and management of glacier-related hazards in high mountains.

In late May 2025, a series of large rock failures from Kleines Nesthorn in the Swiss Lötschental (Lötschen valley) fell directly onto the Birchgletscher (Birch Glacier), loading the latter with around 4 million m3 of rock. On May 28, following several days of acceleration, Birchgletscher collapsed in its entirety, claiming one life and causing the near-total destruction of the historic village of Blatten (which had been fully evacuated prior to the event). Totaling more than 9 million m3 of rock and glacier ice (with a ratio of about 3:1), the rock-ice avalanche dammed the river Lonza and led to the formation of a lake that damaged additional parts of the village.The rock failures that initiated the hazard cascade originated from the north-east face of Kleines Nesthorn, a formerly 3336 meter tall peak. Like all areas at this elevation, this face is expected to have experienced important ground temperature changes in the past decades. In this contribution, we ask how these changes may have affected the observed hazard cascade. We analyzed climatic changes (air temperature and precipitation) and snow cover, simulated permafrost changes, and assessed the geologic preconditioning and failure kinematics. We then attempt to propagate these changes through the hazard cascade to understand their possible impact on the rock slope failures. To do so, we employed a combination of data from weather stations, satellite data, climate models and numerical modeling. Our findings demonstrate the complexity of the Nesthorn-Birchgletscher hazard cascade and highlight challenges and research gaps for assessing the role of permafrost on large rock slope failures in a changing climate.

In May 2023 the village of Brienz/ Brinzauls, Switzerland was evacuated due to high landslide risk, drawing national and international attention. On June 15, 2023, a significant collapse occurred at the site, with a volume of 2 Mm³. This collapse followed a prolonged acceleration phase of a section of an old, partially active deep seated gravitational slope deformation (DSGSD). The Insel compartment is composed of ductile clay-schist at its base, overlaid by porous rauhwacke and brittle dolomites. In the present work, we analyse the complete dynamic and structural evolution of the Insel compartment using data from various monitoring systems, including 3D displacement measurements from a robotic total station (RTS, operational since 2012), bi-annual LiDAR surveys, Doppler radar monitoring of rockfall activity, ground-based InSAR monitoring (since 2018), and automated digital image correlation of high-resolution time-lapse images. We additionally developed simple analytical dynamic models to investigate the behaviour of viscoplastic and frictional materials.The current study identified three key phases of the Insel compartment's evolution: (i) the compartment formation phase, (ii) the Insel acceleration and (iii) the terminal phase. During the formation phase (2018-2022), the compartment extended laterally and in the down-slope direction, and a transition from toppling to sliding kinematics was observed. The acceleration phase started in summer 2022 and was characterized by a prolonged exponential increase in displacement rates, occasionally interrupted with linear growth phases, persisting until early May 2023. In the terminal phase, four short-term surge episodes (lasting days to weeks) were noted, defined by rapid exponential velocity increases followed by stagnation. Surge episodes became more frequent towards the date of collapse and strongly influenced the short-term applicability of classical velocity prediction models such as the Voight’s model.Based on the available data we developed a kinematic model of the Insel compartment, resulting in a two-wedge compound rockslide which moves on a bi-linear sliding plane. The upper, active wedge comprised brittle, heavily fractured dolomites, while the lower, passive wedge primarily consisted of ductile clay-schists. Intense subsidence at the top of the active wedge suggested the formation of a graben structure along pre-existing large-scale lineaments. The sliding planes dipped southward at 50° (active wedge) and 25° (passive wedge), with a sub-vertical internal shear/deformation zone (ISP) evolving at the kink point of the bi-linear sliding plane. The passive wedge exhibited decreasing displacement in downslope direction, indicating internal shearing and rupturing. At least one rupture plane formation was identified within the passive wedge, causing a rapid acceleration followed by velocity stabilization.We could replicate the velocity characteristics of surge episodes by combining analytical dynamic models using viscoplastic and frictional materials. This led us to the conclusion that a complex interplay between rupturing within the passive wedge, displacements along the ISP and mass balance changes due to frontal collapses caused the complex dynamic evolution and hence the difficulties in the short-term applicability of Voight’s model. This comprehensive investigation offers new insights and valuable field observations of the complex interplay of structural, mechanical, and external factors driving the dynamics of compound rockslides.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time series of rockfall events with volumes of 1 m³ and greater since 2018 and serves as automatic traffic control for an important main road. In the period between January 2018 and October 2022, 6743 events were detected, which is 2 orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow area, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that, due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time-series of rockfall events with volumes of 1m³ and bigger since 2018 and serves as automatic traffic control for an important cantonal road. In the period between January 2018 and September 2022, 6743 events were detected, which is two orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow zone, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time-series of rockfall events with volumes of 1m³ and bigger since 2018 and serves as automatic traffic control for an important cantonal road. In the period between January 2018 and September 2022, 6743 events were detected, which is two orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow zone, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time-series of rockfall events with volumes of 1m³ and bigger since 2018 and serves as automatic traffic control for an important cantonal road. In the period between January 2018 and September 2022, 6743 events were detected, which is two orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow zone, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time-series of rockfall events with volumes of 1m³ and bigger since 2018 and serves as automatic traffic control for an important cantonal road. In the period between January 2018 and September 2022, 6743 events were detected, which is two orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow zone, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.

We present and analyze a rockfall catalog from an active landslide complex in Brienz/Brinzauls of the Swiss Alps, collected with a new Doppler radar system. This radar system provides a complete and continuous time-series of rockfall events with volumes of 1m³ and bigger since 2018 and serves as automatic traffic control for an important cantonal road. In the period between January 2018 and September 2022, 6743 events were detected, which is two orders of magnitude higher activity than in stable continental cliffs. A few percent of all rockfall events reached the shadow zone, which hosts an important road and agricultural area. The Doppler radar data set allows us to investigate the triggering factors quantitatively. We found that the background rockfall activity is controlled by seasonal climatic triggers. In winter, more rockfalls are observed during thawing periods, whereas in summer the rockfall activity increases with hourly rainfall intensity. We also found that due to the geological setting in an active landslide complex, increased rockfall activity occurs clustered in space and time, triggered by local displacement hotspots. Thus, monitoring spatial and temporal variations of slope displacement velocity is crucial for detailed rockfall hazard assessment in similar geological settings.