The HBV.IANIGLA Hydrological Model

Over the past 40 years, the HBV (Hydrologiska Byrans Vattenbalansavdelning) hydrological model has been one of the most used worldwide due to its robustness, simplicity, and reliable results. Despite these advantages, the available versions impose some limitations for research studies in mountain watersheds dominated by ice-snow melt runoff (i.e., no glacier module, a limited number of elevation bands, among other constraints). Here we present HBV.IANIGLA, a tool for hydroclimatic studies in regions with steep topography and/or cryospheric processes which provides a modular and extended implementation of the HBV model as an R package. To our knowledge, this is the first modular version of the original HBV model. This feature can be very useful for teaching hydrological modeling, as it offers the possibility to build a customized, open-source model that can be adjusted to different requirements of students and users.Fil: Toum, Jorge Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Masiokas, Mariano Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Villalba, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Pitte, Pierre. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Ruiz, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

Reconstructing the annual mass balance of the Echaurren Norte glacier (Central Andes, 33.5° S) using local and regional hydroclimatic data

Despite the great number and variety of glaciers in southern South America, in situ glacier mass-balance records are extremely scarce and glacier–climate relationships are still poorly understood in this region. Here we use the longest (>  35 years) and most complete in situ mass-balance record, available for the Echaurren Norte glacier (ECH) in the Andes at  ∼  33.5° S, to develop a minimal glacier surface mass-balance model that relies on nearby monthly precipitation and air temperature data as forcing. This basic model is able to explain 78 % of the variance in the annual glacier mass- balance record over the 1978–2013 calibration period. An attribution assessment identified precipitation variability as the dominant forcing modulating annual mass balances at ECH, with temperature variations likely playing a secondary role. A regionally averaged series of mean annual streamflow records from both sides of the Andes between  ∼  30 and 37° S is then used to estimate, through simple linear regression, this glacier's annual mass-balance variations since 1909. The reconstruction model captures 68 % of the observed glacier mass-balance variability and shows three periods of sustained positive mass balances embedded in an overall negative trend over the past 105 years. The three periods of sustained positive mass balances (centered in the 1920s–1930s, in the 1980s and in the first decade of the 21st century) coincide with several documented glacier advances in this region. Similar trends observed in other shorter glacier mass-balance series suggest that the Echaurren Norte glacier reconstruction is representative of larger-scale conditions and could be useful for more detailed glaciological, hydrological and climatological assessments in this portion of the Andes

Contrasting Climates at Both Sides of the Andes in Argentina and Chile

The prominent Andes cordillera induces significant differences in climates between its eastern and western slopes. These climatic differences are largely reflected by contrasting vegetation and ice coverages but remain poorly documented. This study quantifies the abrupt changes of precipitation and cloud properties at both sides of the Andes south of 20°S by using surface daily precipitation and satellite (CloudSat and MODIS) data during the 2006–2016 period. Results show that the precipitation changes drastically and precipitating clouds can be of very different nature on each side of the Andes. In the tropical Andes (20–25°S), precipitation normally falls from a sole layer of thick stratiform and convective precipitating clouds during the warm semester, but the annual mean accumulation is about 10–100 times larger on the eastern than on the western slopes. A sole layer of low stratus clouds dominates over the Pacific coast, occasionally producing light rains, whereas high, thin, and non-precipitating clouds dominate most of the time over the continent. In the subtropical Andes (25–35°S), annual mean precipitation is similar on both sides, however, it falls from convective and stratiform precipitating clouds in the warm semester on the eastern slopes, and from stratiform precipitating clouds in the cold semester, mostly as frozen particles, on the western slopes. These different features on both slopes denote a climatic transition between the tropics and extratropics. In the extratropical Andes (south of 35°S), stratiform cloud types produces precipitation on both sides during all the year, but the annual mean precipitation and cloud frequency are enhanced on the western slopes and strongly reduced on the eastern slopes of the Andes. Cloud frequencies are higher than in the subtropics and evenly distributed as single- or multi-layers of low, middle and high clouds. Frozen particles become important in precipitating clouds over the mountains and on the lee side. These findings demonstrate the significant influence of the Andes cordillera on the climate all along southwestern South America, and constitute an excellent example of how the simple dependence of climate on latitude can be substantially altered by the topography

Eure. Observations récentes sur le donjon de Brionne

Pitte Dominique, Caldéroni Paola, Brabant Jean-Pierre. Eure. Observations récentes sur le donjon de Brionne. In: Bulletin Monumental, tome 156, n°2, année 1998. pp. 173-176

Caracterización y evolución temporal de los deslizamientos activos en las laderas de los cerros solo y techado negro, Valle del Glaciar Torre/Grande, provincia de Santa Cruz

El área de estudio comprende la cuenca del glaciar Torre/Grande, su lago proglaciario y el río Fitz Roy, dentro del Parque Nacional Los Glaciares (PNLG), en el suroeste de la provincia de Santa Cruz (Fig.1A). El parque cuenta con uno de los atractivos turísticos naturales más importantes de la provincia, visitado por miles de turistas al año, siendo la principal actividad económica de la localidad de El Chaltén. El retroceso del glaciar Torre (Masiokas et al. 2015), ha ocasionado la relajación de las laderas que lo contienen, desestabilizando las pendientes del valle y tornándolas susceptibles a movimientos de remoción en masa. Desde el año 2007, se reconoce actividad tanto de la ladera norte del cerro Solo (Winocur et al. 2015), como de la ladera sur del cerro Techado Negro, identificada en esta contribución. Esto constituye un riesgo frente a la posibilidad de desarrollo de un evento súbito que deslice grandes volúmenes de material al lago Torre, provocando una crecida en el río Fitz Roy, Glacier Lake Outburt Flood, que podría generar su desborde causando daños aguas abajo. El objetivo del presente trabajo es identificar los cambios morfológicos ocurridos en los últimos quince años (2007-2022) en ambas laderas y así contribuir al conocimiento de la tasa de movimiento, en relación al retroceso glaciario y su influencia en el potencial proceso de desestabilización.La metodología de trabajo consistió en analizar imágenes satelitales Sentinel-2 disponibles en la plataforma Copernicus Acces Hub, con una resolución espacial de 12,5 m e imágenes de alta resolución CNES-Airbus disponibles en Google Earth Pro, de entre 2,5 m a 50 cm de resolución. Asumiendo el error intrínseco en las imágenes y estableciendo puntos de control, se realizaron diferentes mediciones en el frente del glaciar y en las laderas que lo contienen. Para el análisis del paisaje se decidió contrastar el período 2007-2019 y 2019-2022, con el fin de establecer una actualización desde el último trabajo realizado por Balbi et al. (2019).En la secuencia de imágenes analizadas, entre los años 2007 y febrero de 2022, se aprecian las diferentes posiciones del frente glaciar (Fig.1A), asociado a su continua retracción y adelgazamiento. Del análisis de los resultados, se desprende que en la escarpa principal de la ladera del cerro Solo el material deslizado incrementó su tasa de movimiento drásticamente, casi el doble, comparando los períodos 2007-2019 y 2019-2022, e incluso en este último, el volumen del material deslizado se fue incrementando pudiendo observarse como la escarpa principal asciende incorporando más material del talud (Fig. 1B, D). Para la ladera del cerro Techado Negro las mediciones no arrojaron cambios significativos en el movimiento asociado a la escarpa principal, no obstante se destaca la presencia de nuevas cicatrices y material deslizado que recubre la ladera (Fig.1C). Para el período 2019-2022, se evidencia una pérdida de hielo glaciar que casi duplica el resultado obtenido para el período anterior (Fig.1E, F). Del mismo modo, los valores estimados para la tasa de incremento del área del lago Torre, indican un incremento mayor al doble comparando ambos períodos (Fig.1F).Con este trabajo, se evidencia la relación directa existente entre el retroceso del glaciar Torre/Grande, con el concomitante aumento del volumen del lago Torre y la actividad de los deslizamientos que afectan a las laderas que lo contienen. Sumado a ello, se actualiza información sobre la dinámica de la ladera del cerro Solo demostrando un incremento en la tasa de movimiento, que se duplica en los últimos 3 años, y en la pérdida de masa desde el trabajo llevado a cabo por Balbi et al. (2019). Además, se proporciona un panorama de la ladera del cerro Techado Negro no estudiada previamente. El estado actual de ambas laderas constituye un riesgo a tener en cuenta en relación a los turistas que visitan el parque como así también para los habitantes de El Chaltén. Es menester realizar estudios futuros, en particular en la ladera del cerro Techado Negro, debido a la falta de caracterización de la misma y ante el posible desarrollo de un movimiento súbito que involucre el material morénico inconsolidado que la recubre. Estos trabajos deberán hacer hincapié en el riesgo geológico y la vulnerabilidad presentes, a fin de establecer programas de prevención y mitigación, así como sistemas de alerta temprana, planes de evacuación, educación y concientización ante los peligros geológicos existentes.Fil: Schmidt, Daniela Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Winocur, Diego Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Pitte, Pierre. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaVIII Congreso Argentino de Cuaternario y GeomorfologíaSan JuanArgentinaAsociación Argentina de Cuaternario y Geomorfologí

Rock glacier activity and distribution in the semi-arid Andes of Chile and Argentina detected from dInSAR

International audienceRock glaciers in the semi-arid Central Andes ofChile and Argentina (approx. 28-34°S) are wide-spread elements of the high mountain landscape butthey still need to be studied more thoroughly. Thepresence and activity of this type of ice-rich and creep-ing permafrost has potential consequences for the hy-drological functioning of the watersheds as well asfor the stability of the debris slopes (Trombotto etal, 1997; 1999). Indeed, some cases of rock glacierdestabilization observed in this region (Iribarren, 2010;Bodin and Iribarren, 2012) suggest that the geomor-phological processes related to rock glacier dynamicsmay be changing because of warming conditions intothe ground (Trombotto& Borzotta, 2009). Neverthe-less, up to now, knowledge on rock glacier kinematicsin the Central Andes was restricted to a few sites(Apaloo et al., 2012; UGP-UC, 2011; Arenson et al.,2010) where study and monitoring efforts took placesince generally less than 10 years. On the other side,ongoing human activities in high altitude areas, likemining, are increasingly impacting rock glaciers (Bren-ning, 2008; Brenning and Azócar, 2010), which hasled to substantial efforts from public authorities toevaluate the cryospheric resources in their respectiveterritories. For that purpose, in both Chile and Ar-gentina, inventories of rock glaciers have recently beenreleased (UGP-UC, 2011; IANIGLA, 2010) based onaerial and satellite imagery. Morphological features in-dicatives of the presence of ice-rich permafrost, mainlyrock glaciers, have therefore been mapped. The assess-ment of the activity status of those landforms, whichis of crucial importance for further studying theirsensitivity to climate- and human-induced impacts,is generally done thanks to expert knowledge. Basedon visual interpretation of optical imagery, sometimescombined with in situ observations, this approachinduces subjectivity-related biases and a limited reli-ability of the analysis.To overcome those limitations, and under certainconditions (e.g. orbital geometry, weather conditions,slopes orientation), the space-borne imagery methodcalled differential radar interferometry (d-InSAR) canbe used to produce raster maps of surface changesover large areas and for periods covering a few daysto some months. In our work, we used 17 TerraSAR-X images acquired between April 2014 and January2015 over two zones of the Central Andes (Cordóndel Plata: 33°S; El Tapado: 30°S) to generate 15interferograms (8 in descending mode and 7 in as-cending mode) with a pixel size of 10 m, at 11, 22and 33-day intervals and a baseline of the SAR pairsranging from a few meters to some hundreds of meters.The topographic fringes were removed using the 90-mSRTM global DEM and a smoothing filter has beenapplied to the generated interferometric signal. Thed-InSAR dataset has been locally validated thanksto in situ dGPS measurements (Tapado rock glaciersite) performed between 2010 and 2014. We were ableto evidence several areas of distinct velocity patterns,depending on the glacio-geomorphological activity(glacier/debris-covered glacier/rock glacier) for whicha clear d-InSAR signal could be associated, as alsoobserved in other high mountain sites in the Alpswhere such approach has been previously used.The dataset covers a surface of almost 5100 km2,with a median elevation of 4120 m asl (25-75%quantiles = 3464-4606 m asl) and several hundreds offresh rock glaciers inventoried. We present here a syn-thetic overview of the regional rock glacier’s activitybased on the interpretation of the TSX interferograms.The kinematic characteristics of some interesting rockglaciers is further presented and discussed, especiallyin terms of the correspondence between geomorpho-logical observations and d-InSAR signal, as well asfuture research direction

South American Andes elevation changes from 2000 to 2018, links to GeoTIFFs

Glaciers in the Andes are among the fastest shrinking and largest contributors to sea level rise in the world. They also represent crucial water resources in many tropical and semi-arid portions of this extensive mountain range. Yet, the magnitude of the recent ice loss over the entire Andes cordillera is still debated. Here we present Andean glacier mass changes (from 10°N to 56°S) between 2000 and 2018 using time series of digital elevation models derived from ASTER stereo images. The total mass change is -22.9 ± 5.9 Gt yr-1 (-0.72 ± 0.22 m w.e. yr-1), with the most negative mass balances in the Patagonic Andes (-0.78 ± 0.25 m w.e. yr-1) and the Tropical Andes (-0.42 ± 0.24 m w.e. yr-1), and relatively moderate losses (-0.28 ± 0.18 m w.e. yr-1) in the Dry Andes. Sub-period analysis (2000-2009 vs. 2009-2018) reveals steady mass loss in the Tropics and south of 45°S. Conversely, a shift from slightly positive to strongly negative mass balance is measured between 26° and 45°S. In this latter region, the rapid glacier loss in recent years coincides with extremely dry conditions since 2010 and partially helped to mitigate the negative hydrological impacts of this severe drought. These results provide a comprehensive, high resolution and multi-decadal dataset of recent Andes-wide glacier mass changes that constitutes a relevant basis for calibration and validation of hydrological and glaciological models intended to project future glacier changes and their hydrological impacts

La pomme de terre gourmande

International audienc

Ice Mass Loss in the Central Andes of Argentina Between 2000 and 2018 Derived From a New Glacier Inventory and Satellite Stereo-Imagery

International audienceBased on the recently released National Glacier Inventory (NGI), we analyzed the characteristics and the mass balance rates of ice masses in the Argentinean Central Andes (ca. 30°-37°S). The NGI provides unprecedented information on area, number and distribution of different ice masses, including debris-covered glaciers and rock glaciers. In the Central Andes, a number of 8,076 ice masses were identified covering a total area of 1767 km 2. For the period 2000-2018, a general lowering of the ice surface was observed with a region-wide mass balance rate of −0.18 ± 0.19 m w.e. yr −1. Clear differences depending on the debris coverage of the different ice masses were identified, with mass balance rates ranging from −0.36 ± 0.19 m w.e. yr −1 for partly debris-covered glaciers to −0.02 ± 0.19 m w.e. yr −1 for rock glaciers. Considering different sub-periods, the regionwide mass balance rate was slightly positive (+0.12 ± 0.23 m w. e. yr −1) from 2000 to 2009 and negative (−0.21 ± 0.30 m w.e. yr −1) from 2009 to 2018. A comparison with the Randolph Glacier Inventory (RGI version 6.0) indicates that the NGI provides more detailed information regarding different type of ice masses whereas region-wide mass balance rates show limited sensitivity to the choice of the inventory. The inclusion of rock glaciers and "debris-covered ice with rock glacier" in the NGI causes mass balance rates to be slightly less negative than when using the RGI. Since the Central Andes are experiencing an unprecedented decade-long drought, our study provides crucial information to estimate current and future hydrological contribution of the different type of ice masses to river discharge in the arid subtropical Andes