Predicting Landslides Using Locally Aligned Convolutional Neural Networks

Landslides, movement of soil and rock under the influence of gravity, are common phenomena that cause significant human and economic losses every year. Experts use heterogeneous features such as slope, elevation, land cover, lithology, rock age, and rock family to predict landslides. To work with such features, we adapted convolutional neural networks to consider relative spatial information for the prediction task. Traditional filters in these networks either have a fixed orientation or are rotationally invariant. Intuitively, the filters should orient uphill, but there is not enough data to learn the concept of uphill; instead, it can be provided as prior knowledge. We propose a model called Locally Aligned Convolutional Neural Network, LACNN, that follows the ground surface at multiple scales to predict possible landslide occurrence for a single point. To validate our method, we created a standardized dataset of georeferenced images consisting of the heterogeneous features as inputs, and compared our method to several baselines, including linear regression, a neural network, and a convolutional network, using log-likelihood error and Receiver Operating Characteristic curves on the test set. Our model achieves 2-7% improvement in terms of accuracy and 2-15% boost in terms of log likelihood compared to the other proposed baselines.Comment: Published in IJCAI 202

Estudio geomorfológico y paleoambiental de las avalanchas de escombros de Maca y Lari, Valle de Colca

El Valle del Colca, sur de Perú, es una zona geológicamente activa, afectada por la ocurrencia de deslizamientos. En este estudio nos centramos en la estratigrafía de los sedimentos desplazados por los movimientos de masas de Maca y Lari. El Río Colca va socavando constantemente una secuencia de sedimentos lacustres subyacentes a un depósito de la avalancha de escombros. Esto causa hundimiento y deformación en toda la secuencia, afectando a los pueblos asentados en la parte alta. Se ha realizado un estudio textural, estructural y estratigráfico en campo de la secuencia involucrada en los deslizamientos. La datación por 14C (radiocarbono) de los sedimentos orgánicos y el análisis paleomagnético de los sedimentos lacustres se aplicaron para restringir la edad y la relación espacial del diamicton (material detrítico con partículas de distintos tamaños) de avalancha de escombros involucrado en la deformación. Nuestros resultados preliminares indican que la avalancha de escombros de Maca es más joven que los depósitos de avalancha de escombros de Lari. El evento en Maca conserva la superficie original, no deformó significativamente los sedimentos lacustres inferiores y represó el río formando un lago. La avalancha de escombros de Lari no conserva la superficie original y está cubierta por hasta 10 m de sedimentos. Durante el emplazamiento, se rasgaron y deformaron profundamente los sedimentos lacustres subyacentes. Los sedimentos lacustres por encima y por debajo de ambas avalanchas registran magnetización de polaridad normal. Se hizo la correlación de los sedimentos lacustres debajo de las avalanchas con el subchron de Jaramillo y los sedimentos sobre las avalanchas con el Chron Brunhes. La cronoestratigrafía paleomagnética puede ayudar a limitar mejor los eventos geológicos en el Valle del Colca. La edad radiocarbono de sedimentos lacustres en la parte superior de la secuencia de Maca, indica una edad de emplazamiento de avalancha de escombros de 0.010-0.008 Ma. El deslizamiento pudo haber ocurrido en un clima húmedo y de desglaciación. Una mejor comprensión de la dinámica de emplazamiento de las paleo-avalanchas de escombros ayudará a entender los peligros actuales y futuros en el Valle del Colca

Mount Meager, a glaciated volcano in a changing cryosphere: hazard and risk challenges

Mount Meager is a glacier-clad volcanic complex in British Columbia, Canada. It is known for its landslides, of which the 2010 is the largest Canadian historical landslide. In this thesis we investigated slope instability processes at Mount Meager volcano and the effects of ongoing deglaciation. We used a variety of methods including field and remote, geological, geomorphological and structural mapping to characterize glacial and landslide activity at Mount Meager. We used Structure from Motion photogrammetry (SfM) and Lidar to produce digital surface models and InSAR to monitor slope deformation. We applied SfM to historic photography to document glacier and landslide activity at Mount Meager. We discussed a model of growth and erosion of a volcano in glacial and interglacial periods, and the scientific and dissemination value of historic 3D topographic reconstruction. We described the 2010 Mount Meager landslide deposit to interpret emplacement dynamics and kinematics. The 2010 landslide separated in water-rich and water-poor phases that had different runout and distinct deposits. We analyzed historic airphotos to constrain the slope deformation prior to the 2010 collapse. The glacier near the toe of the slope retreated in the failure lead up, the collapse evolved in four subfailures involving the whole volcanic sequence and some basement rocks. We estimated 6 × 106 m3 of water in the slope, that allowed the separation of the frontal water-rich phase. The total failure volume was 53 ± 3.8 × 106 m3. We identified 27 large (>5×105 m2) unstable slopes at Mount Meager and calculated ~1.3 km3 of ice loss since 1987. The west flank of Plinth peak and Devastation Creek valley moved up to -34±10 mm and -36±10 mm, respectively, over a 24-day period during the summer of 2016. The failure of these slopes could impact infrastructures and communities downstream of the volcano. The resulting decompression on the volcanic edifice after the failure of Plinth peak would affect the stress field to a depth of 6 km and up to 4 MPa. This sudden decompression could lead to hydrothermal or magmatic eruption

Mount Meager, un volcan glaciaire dans une cryosphère en mutation : dangers et risques

Mount Meager is a glacier-clad volcanic complex in British Columbia, Canada. It is known for its landslides, of which the 2010 is the largest Canadian historical landslide. In this thesis we investigated slope instability processes at Mount Meager volcano and the effects of ongoing deglaciation. We used a variety of methods including field and remote, geological, geomorphological and structural mapping to characterize glacial and landslide activity at Mount Meager. We used Structure from Motion photogrammetry (SfM) and Lidar to produce digital surface models and InSAR to monitor slope deformation. We applied SfM to historic photography to document glacier and landslide activity at Mount Meager. We discussed a model of growth and erosion of a volcano in glacial and interglacial periods, and the scientific and dissemination value of historic 3D topographic reconstruction. We described the 2010 Mount Meager landslide deposit to interpret emplacement dynamics and kinematics. The 2010 landslide separated in water-rich and water-poor phases that had different runout and distinct deposits. We analyzed historic airphotos to constrain the slope deformation prior to the 2010 collapse. The glacier near the toe of the slope retreated in the failure lead up, the collapse evolved in four subfailures involving the whole volcanic sequence and some basement rocks. We estimated 6 × 106 m3 of water in the slope, that allowed the separation of the frontal water-rich phase. The total failure volume was 53 ± 3.8 × 106 m3. We identified 27 large (>5×105 m2) unstable slopes at Mount Meager and calculated ~1.3 km3 of ice loss since 1987. The west flank of Plinth peak and Devastation Creek valley moved up to -34±10 mm and -36±10 mm, respectively, over a 24-day period during the summer of 2016. The failure of these slopes could impact infrastructures and communities downstream of the volcano. The resulting decompression on the volcanic edifice after the failure of Plinth peak would affect the stress field to a depth of 6 km and up to 4 MPa. This sudden decompression could lead to hydrothermal or magmatic eruptions.Mount Meager est un complexe volcanique glaciaire en British Columbia (Canada). Il est connu pour ses glissements de terrain, dont celui de 2010 étant le plus grand glissement de terrain historique au Canada. Dans cette thèse, nous avons étudié les processus d'instabilités du volcan Mont Meager ainsi que les effets de la déglaciation en cours. Nous avons utilisé une approche pluridisciplinaire, intégrant la cartographie géologique, géomorphologique et structurelle, du terrain et de la télédétection, pour caractériser l'activité glaciaire et les glissements de terrain au Mount Meager. Nous avons utilisé la photogrammétrie Structure from Motion (SfM) et la technologie Lidar pour produire des modèles numériques de terrain, et techniques InSAR pour surveiller le mouvement et la déformation des pentes du volcan. Nous avons appliqué la technique SfM à des photographies aériennes historiques pour documenter les activités des glaciers et des glissements de terrain au Mount Meager. Nous avons discuté un modèle de croissance et d'érosion d'un volcan en période glaciaire et interglaciaire, ainsi que la valeur scientifique et de vulgarisation de la reconstruction topographique 3D. Nous avons décrit les dépôts de glissement de terrain de 2010 à Mount Meager pour interpréter la dynamique de leur mise en place. Le glissement de terrain de 2010 s'est divisé en phases riches en eau et pauvres en eau, ayant des distances d'écoulement différentes et des dépôts distincts. Nous avons analysé des photographies aériennes historiques remontant à 1948, afin de documenter la déformation de la pente avant l'effondrement de 2010. Le glacier situé a proximité du pied de la pente a reculé durant les années précédents la rupture. Cette effondrement a évolué en quatre sous-effondrements, impliquant toute la séquence volcanique et le socle. Nous avons estimé 6 × 106 m3 d'eau dans la pente, ce qui a permis la séparation de la phase frontale riche en eau. Le volume total d'effondrement est 53 ± 3.8 × 106 m3. Nous avons identifié 27 grands (>5×105 m2) flancs instables au Mount Meager et calculé a ~1.3 km3 de récession des glaciers depuis 1987. Le flanc ouest de Plinth Peak et de la vallée de Devastation Creek se sont déplacés de -34±10 mm -36±10 mm, respectivement, dans un période de 24 jours pendant l'été 2016. L’effondrement de ces flancs pourrait avoir un impact important sur les infrastructures et les communautés en aval du volcan. La décompression résultant de l'édifice volcanique après l'effondrement du flanc ouest de Plinth Peak affecterait le champ de contrainte à une profondeur de 6 km et jusqu'à 4 MPa. Cette décompression soudaine pourrait mener des éruptions hydrothermales et magmatiques. Un important glissement de terrain pourrait donc avoir joué un rôle dans le déclenchement de l'éruption de 2360 cal BP

Comparative study of molards on the Mount Meager debris avalanche, Canada, and on Hale crater ejecta, Mars

International audienceMolards are cones of debris that result from the disaggregation of ice-cemented blocks transported by mass movements (e.g., Cruden, Can. J. Earth Sci 1982; Milana, PPP 2016). Recently, the origin of molards has been directly linked to permafrost degradation (Milana, PPP 2016; Morino et al., EPSL 2018). On Earth, permafrost degradation has accelerated in periglacial environments (e.g., Brown and Romanovsky, PPP 2008), but few landforms exist to track this process over time, and molards are a rare example that can serve this purpose. A process similar to permafrost degradation is thought to occur also on Mars, where water ice is known to exist as ground ice polewards of 30-40° in both hemispheres (Byrne et al., Science 2009; Feldman et al., JGR 2004), and where volatiles (H2O, CO2, etc.) can easily change phase (Fanale and Cannon, JGR 1974). Volatile loss should play an important role in landscape evolution of Mars, so finding distinctive landforms that testify this under-debate process can aid in understanding the processes that shape the surface of the planet. Here, we present a comparative study of molards that we have found in the Mount Meager debris-avalanche deposits on Earth with conical landforms that we have identified in the flows emanating from the ejecta deposits of the one billion year old Hale crater on Mars. The Mount Meager debris avalanche (British Columbia, Canada) is the largest landslide in the Canadian history, and permafrost degradation is thought to have contributed to the release of the failure (Roberti et al., Geosphere 2017) and in the development of the molards. We compare morphometric and planimetric measurements of molards on Earth with those for the molard-like features identified in the ejecta of the Hale Crater on Mars, whose ice-rich nature has already been proposed based on other landforms (Jones et al., Icarus 2011). The visual similarity of the molards of the Mount Meager debris avalanche and of the ejecta flow of Hale crater suggest that they are both formed via the degradation of ice-rich surface material. The finding of candidate molards on Mars adds to the evidence that the impact of Hale Crater was into ice-rich materials, and these landforms have the potential to constrain both the initial ground ice content at the Hale impact site, but also the conditions during ejecta emplacement. Our study shows that permafrost degradation/volatile loss can leave a significant geomorphic fingerprint when combined with rapid mass movements in periglacial terrains on Earth and on Mars

Water in volcanoes: evolution, storage and rapid release during landslides.

International audienceVolcanoes can store and drain water that is used as a valuable resource by populations living on their slopes. The water drainage and storage pattern depend on the volcano lithologies and structure, as well as the geological and hydrometric settings. The drainage and storage pattern will change according to the hydrometric conditions, the vegetation cover, the eruptive activity and the long- and short-term volcano deformation. Inspired by our field observations and based on geology and structure of volcanic edifices, on hydrogeological studies, and modelling of water flow in opening fractures, we develop a model of water storage and drainage linked with volcano evolution. This paper offers a first-order general model of water evolution in volcanoes.The volcano’s water plays an important role in volcano stability and instability. Nevertheless, the migration and storage of volcanic water prior and during landslide have not been extensively studied in regard to volcano evolution. We further explore this role and its impact on debris avalanche emplacement behaviour. Isolated water-saturated domains will favour ductile deformation, and unequal distribution of water within the debris avalanche partly explains the coeval occurrence of brittle and ductile deformation, indicating complex rheologies, and varied emplacement mechanisms. If the volcano prior to landslide is storing large amounts of water, this water will quickly flow in the landslide and will form a basal slurry upon which the avalanche will spread further

Evidence for ice in the ejecta flows of Hale Crater, Mars

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