Journal of Geophysical Research: Earth Surface

Journal: Journal of Geophysical Research: Earth Surface

Abbreviation

J. geophys. res. Earth surf.

Publisher

Wiley

ISSN

0148-0227
2169-9003
2169-9011

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Publications 1 - 10 of 33

Regional‐Scale Investigation of Preconditioning Factors of Rock Slope Instabilities in NW Bhutan
Dini, Benedetta; Aaron, Jordan; Manconi, Andrea; et al. (2020)
Journal of Geophysical Research: Earth Surface
We present a new inventory of large rock slope instabilities and an extensive structural data set for northwestern Bhutan. Our data set is largely based on satellite observations, such as optical images and high‐resolution digital surface models, complemented with field observations. Kinematic analyses over seven different structural domains recognized in the study region were carried out to investigate structural control over the landslide distribution at a regional scale. In order to account for the sampling heterogeneity in the different data sets, a weighting system to the structural data is proposed. The results show that structural control exists in five out of seven domains, with foliation strongly influencing the sliding mechanisms. A lithological control appears also evident, with sedimentary rocks showing the highest landslide densities in the region. This study demonstrates how methodologies built on remote sensing data are suitable to investigate landslide predisposition at regional scales especially in largely inaccessible areas.
A Depth-Averaged Material Point Method for Shallow Landslides: Applications to Snow Slab Avalanche Release
Guillet, Louis; Blatny, Lars; Trottet, Bertil; et al. (2023)
Journal of Geophysical Research: Earth Surface
Shallow landslides pose a significant threat to people and infrastructure. Despite significant progress in the understanding of such phenomena, the evaluation of the size of the landslide release zone, a crucial input for risk assessment, still remains a challenge. While often modeled based on limit equilibrium analysis, finite or discrete elements, continuum particle-based approaches like the Material Point Method (MPM) have more recently been successful in modeling their full 3D elasto-plastic behavior. In this paper, we develop a depth-averaged Material Point Method (DAMPM) to efficiently simulate shallow landslides over complex topography based on both material properties and terrain characteristics. DAMPM is a rigorous mechanical framework which is an adaptation of MPM with classical shallow water assumptions, thus enabling large-deformation elasto-plastic modeling of landslides in a computationally efficient manner. The model is here demonstrated on the release of snow slab avalanches, a specific type of shallow landslides which release due to crack propagation within a weak layer buried below a cohesive slab. Here, the weak layer is considered as an external shear force acting at the base of an elastic-brittle slab. We verify our model against previous analytical calculations and numerical simulations of the classical snow fracture experiment known as Propagation Saw Test. Furthermore, large scale simulations are conducted to investigate cross-slope crack propagation and the complex interplay between weak layer dynamic failure and slab fracture. In addition, these simulations allow us to evaluate and discuss the shape and size of avalanche release zones over different topographies. Given the low computational cost compared to 3D MPM, we expect our work to have important operational applications in hazard assessment, in particular for the evaluation of release areas, a crucial input for geophysical mass flow models. Our approach can be easily adapted to simulate both the initiation and dynamics of various shallow landslides, debris and lava flows, glacier creep and calving.
Enhanced Rainfall‐Induced Shallow Landslide Activity Following Seismic Disturbance—From Triggering to Healing
Leshchinsky, Ben; Lehmann Grunder, Peter Ulrich; Or, Dani (2021)
Journal of Geophysical Research: Earth Surface
Evidence suggests that following earthquakes, landslide activity, and susceptibility remain elevated for months to years after cessation of shaking. In landslides constrained within the soil mantle, enhanced post‐seismic activity may be attributed to persistence of progressive failure surface development that results in delayed triggering. With subsequent post‐seismic hydrologic disturbance, a commensurate decay in activity over time reflects evacuation of damaged hillslope materials and mechanical healing of colluvial media and vegetation recovery. In this study, we propose a hydromechanical model for representing the interplay of these processes including trends in timing and magnitude of post‐seismic shallow landslide activity. The hydromechanical model considers seismic or hydrologic disturbances as drivers for failure surface development in the soil mantle over a hillslope with commensurate weakening through accumulation of internal compression, shear softening, and loss of root strength. In the absence of well‐instrumented post‐seismic landslide measurement of evolving stress conditions and deformation, predictions were made against a unique field case study where hydrologically induced hillslope failure kinematics and internal compression were measured. The model accounts for seismic disturbances, demonstrating that certain peak ground accelerations directly reduce subsequent rainfall‐induced landslide‐triggering thresholds relative to undisturbed hillslopes. The model framework can be used to describe progressive, post‐seismic landslide activity, demonstrating that consideration of root or soil healing may suppress subsequent landslide triggering and contribute toward recovery to pre‐seismic disturbance levels of strength. Factors such as shear softening, vegetation, and healing are explored in the context of the temporal evolution of landslide rates after a seismic event. The results of this paper show mechanistically how (1) progressive development or cessation of a failure surface in active, post‐seismic landslides may describe elevated post‐seismic landslide rates and (2) that hillslope healing plays a modest role in the magnitude and timescale of attenuated landslide activity. © 2020 American Geophysical Union
Melt-Induced Fractionation of Major Ions and Trace Elements in an Alpine Snowpack
Avak, Sven E.; Trachsel, Jürg C.; Edebeli, Jacinta; et al. (2019)
Journal of Geophysical Research: Earth Surface
Understanding the impact of melting on the preservation of atmospheric compounds in high‐Alpine snow and glacier ice is crucial for future reconstruction of past atmospheric conditions. However, detailed studies investigating melt‐related changes of such proxy information are rare. Here we present a series of five snow pit profiles of 6 major ions and 34 trace elements at Weissfluhjoch, Switzerland, collected between January and June 2017. Atmospheric composition was preserved during the cold season, while melting toward the summer resulted in preferential loss of certain species from the snowpack or enrichment at the base of the snowpack. Increasing mobilization of major ions with meltwater (NH4+ < Cl− ~ Na+ < NO3− ~ Ca2+ ~ SO42−) can be related to their stronger enrichment at ice crystal surfaces during snow metamorphism. Results for trace elements show that less abundant elements such as Ce, Eu, La, Mo, Nd, Pb, Pr, Sb, Sc, Sm, U, and W were best preserved and may still serve as tracers to reconstruct past natural and anthropogenic atmospheric emissions from melt‐affected snow pit and ice core records. The obtained elution behavior matches the findings from another high‐Alpine site (upper Grenzgletscher) for major ions and the large majority of investigated trace elements. Both studies indicate that water solubility and location at the microscopic scale are likely to determine the relocation behavior with meltwater and also suggest that the observed species‐dependent preservation from melting snow and ice is representative for the Alpine region, reflecting Central European atmospheric aerosol composition.
Interannual Dynamics of Ice Cliff Populations on Debris-Covered Glaciers From Remote Sensing Observations and Stochastic Modeling
Kneib, Marin; Miles, Evan S.; Buri, P.; et al. (2021)
Journal of Geophysical Research: Earth Surface
Ice cliffs are common on debris-covered glaciers and have relatively high melt rates due to their direct exposure to incoming radiation. Previous studies have shown that their number and relative area can change considerably from year to year, but this variability has not been explored, in part because available cliff observations are irregular. Here, we systematically mapped and tracked ice cliffs across four debris-covered glaciers in High Mountain Asia for every late ablation season from 2009 to 2019 using high-resolution multi-spectral satellite imagery. We then quantified the processes occurring at the feature scale to train a stochastic birth-death model to represent the cliff population dynamics. Our results show that while the cliff relative area can change by up to 20% from year to year, the natural long-term variability is constrained, thus defining a glacier-specific cliff carrying capacity. In a subsequent step, the inclusion of external drivers related to climate, glacier dynamics, and hydrology highlights the influence of these variables on the cliff population dynamics, which is usually not a direct one due to the complexity and interdependence of the processes taking place at the glacier surface. In some extreme cases (here, a glacier surge), these external drivers may lead to a reorganization of the cliffs at the glacier surface and a change in the natural variability. These results have implications for the melt of debris-covered glaciers, in addition to showing the high rate of changes at their surface and highlighting some of the links between cliff population and glacier state.
Dynamics of the Bingham Canyon rock avalanches (Utah, USA) resolved from topographic, seismic, and infrasound data
Moore, Jeffrey R.; Pankow, Kristine L.; Ford, Sean R.; et al. (2017)
Journal of Geophysical Research: Earth Surface
Impacts of Rainstorm Intensity and Temporal Pattern on Caprock Cliff Persistence and Hillslope Morphology in Drylands
Shmilovitz, Yuval; Tucker, Gregory E.; Rossi, Matthew W.; et al. (2024)
Journal of Geophysical Research: Earth Surface
Hillslope topographic change in response to climate and climate change is a key aspect of landscape evolution. The impact of short-duration rainstorms on hillslope evolution in arid regions is persistently questioned but often not directly examined in landscape evolution studies, which are commonly based on mean climate proxies. This study focuses on hillslope surface processes responding to rainstorms in the driest regions of Earth. We present a numerical model for arid, rocky hillslopes with lithology of a softer rock layer capped by a cliff-forming resistant layer. By representing the combined action of bedrock and clast weathering, cliff-debris ravel, and runoff-driven erosion, the model can reproduce commonly observed cliff-profile morphology. Numerical experiments with a fixed base level were used to test hillslope response to cliff-debris grain size, rainstorm intensities, and alternation between rainstorm patterns. The persistence of vertical cliffs and the pattern of sediment sorting depend on rainstorm intensities and the size of cliff debris. Numerical experiments confirm that these two variables could have driven the landscape in the Negev Desert (Israel) toward an observed spatial contrast in topographic form over the past 10(5)-10(6) years. For a given total storm rain depth, short-duration higher-intensity rainstorms are more erosive, resulting in greater cliff retreat distances relative to longer, low-intensity storms. Temporal alternation between rainstorm regimes produces hillslope profiles similar to those previously attributed to Quaternary oscillations in the mean climate. We suggest that arid hillslopes may undergo considerable geomorphic transitions solely by alternating intra-storm patterns regardless of rainfall amounts.
Dynamics of Active Subglacial Lakes in Recovery Ice Stream
Dow, Christine F.; Werder, Mauro; Babonis, Greg; et al. (2018)
Journal of Geophysical Research: Earth Surface
Shallow shelf approximation as a "sliding law'' in a thermomechanically coupled ice sheet model
Bueler, Ed; Brown, Jed (2009)
Journal of Geophysical Research: Earth Surface
Draping or overriding
Hindmarsh, Richard C.A.; Leysinger Vieli, Gwendolyn J.-M.C.; Raymond, Mélanie J.; et al. (2006)
Journal of Geophysical Research: Earth Surface

Publications 1 - 10 of 33

Journal: Journal of Geophysical Research: Earth Surface

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