Papers by Silvana Moragues
Frontiers in Earth Science
A number of glaciological observations on debris-covered glaciers around the globe have shown a d... more A number of glaciological observations on debris-covered glaciers around the globe have shown a delayed length and mass adjustment in relation to climate variability, a behavior normally attributed to the ice insulation effect of thick debris layers. Dynamic interactions between debris cover, geometry and surface topography of debris-covered glaciers can nevertheless govern glacier velocities and mass changes over time, with many glaciers exhibiting high thinning rates in spite of thick debris cover. Such interactions are progressively being incorporated into glacier evolution research. In this paper we reconstruct changes in debris-covered area, surface velocities and surface features of three glaciers in the Patagonian Andes over the 1958–2020 period, based on satellite and aerial imagery and Digital Elevation Models. Our results show that debris cover has increased from 40 ± 0.6 to 50 ± 6.7% of the total glacier area since 1958, whilst glacier slope has slightly decreased. The ge...
El retroceso y adelgazamiento de los glaciares a nivel mundial en las últimas décadas inciden dir... more El retroceso y adelgazamiento de los glaciares a nivel mundial en las últimas décadas inciden directamente sobre la estabilidad de las laderas. La cuenca del glaciar Upsala y los glaciares del Brazo Norte del lago Argentino, han sufrido un marcado retroceso generando valles con pronunciadas pendientes y cubiertas con depósitos morrénicos inestables. Las laderas se encuentran fuertemente desestabilizadas, favoreciendo la generación de procesos geomorfológicos paraglaciales. El objetivo de este estudio es identificar y analizar la geomorfología paraglacial, asociada a los procesos de inestabilidad. Se realiza un análisis geomorfológico del terreno a través de la combinación de parámetros morfométricos y factores intervinientes que condicionan y desencadenan estos procesos, mediante el uso de imágenes de satélite. Los resultados muestran que la geomorfología paraglacial se encuentra influenciada por la combinación de: (i) parámetros morfométricos del terreno, entre ellos, elevaciones d...
Colapsos De Morenas Posiblemente Asociados a La Deglaciación Pleistocena en Los Andes Centrales De Argentina
Grandes colapsos gravitacionales se han identificado en el Parque Aconcagua (32oS) ubicados prefe... more Grandes colapsos gravitacionales se han identificado en el Parque Aconcagua (32oS) ubicados preferentemente en sectores periglaciares con cotas inferiores a los glaciares de escombros activos. Algunos de estos grandes deslizamientos, en particular en el valle del rio Vacas, estan originados en depositos de morenas laterales de posible edad Pleistocena si se correlacionan con el avance Almacenes. Por ende, estos colapsos se interpretan como procesos paraglaciares ocurridos luego del retroceso de la masa glacial en el Pleistoceno tardio- Holoceno. Sin embargo, estas grandes masas de morenas colapsadas estan asociadas, en la actualidad, a fenomenos de reptacion de permafrost generando glaciares de escombros activos. Estos cuerpos criogenicos posiblemente desarrollados en el Holoceno podrian evidenciar un periodo de enfriamiento en los Andes Centrales. Este trabajo contribuye al entendimiento de estos procesos geomorfologicos posiblemente acoplados acaecidos en diferentes ciclos climati...
Andean Geology, 2021
Glaciation and deglaciation modify the stress of the slopes affected by these processes and can t... more Glaciation and deglaciation modify the stress of the slopes affected by these processes and can trigger their instability and landslides. This study describes, characterizes and reconstructs a large rotational landslide of soil and moraine material, which occurred on February 10, 2013 on the western slope of Upsala Channel, North Branch of Argentino Lake, in Southern Patagonia. With this aim a qualitative analysis of the slope condition before and after the date of the landslide occurrence, the possible conditioning and triggering factors, and the destructive consequences of the related tsunami that affected the margins of the lake was carried out. To reconstruct the state of the slope before and after the event, techniques of photo-interpretation of optical satellite imagery, digital elevation models, historical photographs, in situ observations, bathymetric data and stories of the park rangers of Los Glaciares National Park were used. The retreat of the Upsala Glacier has caused t...
Natural Hazards, 2020
Your article is protected by copyright and all rights are held exclusively by Springer Nature B.V... more Your article is protected by copyright and all rights are held exclusively by Springer Nature B.V.. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Cuadernos de Investigación Geográfica, 2020
Puente del Inca is a natural monument standing over the Cuevas river in Mendoza, Argentina. The b... more Puente del Inca is a natural monument standing over the Cuevas river in Mendoza, Argentina. The bridge currently exhibits structural deterioration due to natural and anthropic factors. This article seeks to offer a contribution to the conservation and restoration works of Puente del Inca by integrating instruments and technologies that allow the assessment of the health state of the natural bridge. The study relied on visual inspection, accretion-erosion rate measurements, hydrothermal flow characterization, ground-penetrating radar, soil dielectric sensor, Global Navigation Satellite System, laboratory testing, Structure from Motion, the Finite Element Method and ambient vibration testing. The results show that the morphology and health of the natural bridge depend on the dynamic balance between the erosion and the geobiological system intervening in the formation of the travertine constituting the natural bridge. The computational structural modeling demonstrates that there is a c...
Cuadernos de Investigación Geográfica, 2019
En el presente estudio, se aborda el diseño y desarrollo de un modelo numérico computacional del ... more En el presente estudio, se aborda el diseño y desarrollo de un modelo numérico computacional del comportamiento del ciclo oscilatorio estacional de avance y retroceso del glaciar Perito Moreno, denominado MO-ACAR. Dentro de su comportamiento oscilatorio, en algunos años el glaciar avanza y alcanza la Península de Magallanes formando un dique de hielo. Por ello, el objetivo del MO-ACAR es simular la posición frontal diaria del glaciar y la ocurrencia de eventos de formación de los diques de hielo durante el periodo 1994-2018. El modelo fue calibrado y validado a partir de un proceso de optimización iterativo, basado en la maximización de valores de correlación y minimización de errores de distancia. La simulación de la ocurrencia de la formación de diques de hielo y la oscilación de la posición frontal lograron altas prestaciones, alcanzando óptimos valores de correlación (0,99) y bajos errores de posición (9,56 ± 13,94 m), respectivamente. Los resultados demuestran que la dinámica d...
Cuadernos de Investigación Geográfica, 2019
El retroceso y adelgazamiento de los glaciares a nivel mundial en las últimas décadas inciden dir... more El retroceso y adelgazamiento de los glaciares a nivel mundial en las últimas décadas inciden directamente sobre la estabilidad de las laderas. La cuenca del glaciar Upsala y los glaciares del Brazo Norte del lago Argentino, han sufrido un marcado retroceso generando valles con pronunciadas pendientes y cubiertas con depósitos morrénicos inestables. Las laderas se encuentran fuertemente desestabilizadas, favoreciendo la generación de procesos geomorfológicos paraglaciales. El objetivo de este estudio es identificar y analizar la geomorfología paraglacial, asociada a los procesos de inestabilidad. Se realiza un análisis geomorfológico del terreno a través de la combinación de parámetros morfométricos y factores intervinientes que condicionan y desencadenan estos procesos, mediante el uso de imágenes de satélite. Los resultados muestran que la geomorfología paraglacial se encuentra influenciada por la combinación de: (i) parámetros morfométricos del terreno, entre ellos, elevaciones d...
CATENA, 2019
We present results of the estimation of surface changes associated with slope instability process... more We present results of the estimation of surface changes associated with slope instability processes on the Upsala Channel by remote sensing and statistic techniques. Hillslopes, involving lateral moraines, of Upsala Channel at the Argentino Lake have become potentially unstable due to the retreat of Upsala Glacier during the last century. The glaciation and deglaciation processes modify the tensions on the slope stability and may generate landslide processes. A landslide movement destroyed the western edge of the Upsala Channel in February 2013. In addition, the region represents a great tourist attraction usually ships navigate through the Upsala Channel seeing impressive landscapes, especially the Upsala Glacier, stand out. Due to this risky situation the necessity of increasing the knowledge in the area has arisen but has not been addressed yet. Therefore, the main goal of the present study is to investigate the multivariate statistical techniques by the principal component analysis (PCA) and discriminative analysis (DA) in four testing areas (TAS n). Besides, we include Pearson's correlation coefficient (PCC) and normal distribution (ND) to determine whether the testing areas suffered slope movements or were temporally stable. The study is based on Landsat optical satellite images, acquired during the period from October 2001 to April 2015. The results show that TAS 1,2,4 are less stable, whereas TAS 5 is a more stable area as compared to another TAS. The PC1 and PC2 principal components explained the total variability of the 76% data. The total apparent error of DA reached 2.2% points. The PCC achieved a positive trend during the years when movement on the slope surface was not observed; while during the periods when slope instability was observed, the correlation showed a negative trend. The TAS n that had shown a different behavior presented contrasted Gaussian bells; they are more flattened in those years with instability events.
Andean Geology, 2017
In this study we present surface velocities estimation for the Upsala glacier catchment, South Pa... more In this study we present surface velocities estimation for the Upsala glacier catchment, South Patagonian Ice Field (SPI) during the summer season of years 2013 (January-March) and 2014 (March-April), including the Bertacchi, Cono, and Murallón tributaries using satellite images from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The Cross-Correlation method was applied by COSI-Corr technique with sub-pixel accuracy. In general, it should be noted that the SPI glaciers, and Upsala glacier in particular, are fast-flowing ice bodies, which makes the technique works properly. Results of surface velocities estimation ranged from 0.22 to 2.93 md-1 for January-March 2013 and 0.12 to 5.8 md-1 for March-April 2014. In summary, COSI-Corr can achieved accurate and reliable results for glacier displacements and surface velocities estimation, also contributing in the better knowledge of the velocities change processes in time, taking into account Upsala is one of the mo...
Journal of Glaciology, 2016
ABSTRACTDespite renewed efforts to better understand glacier change and recognize glacier change ... more ABSTRACTDespite renewed efforts to better understand glacier change and recognize glacier change trends in the Andes, relatively large areas in the Andes of Argentina and Chile are still not investigated. In this study, we report on glacier elevation and mass changes in the outer region of the Northern and Southern Patagonian Icefields in the Southern Patagonian Andes. A newly-compiled Landsat ETM+ derived glacier inventory (consisting of 2253 glaciers and ~1314 ± 66 km2of ice area) and differencing of the SRTM and SPOT5 DEMs were used to derive glacier-specific elevation changes over the 2000–12 period. The investigated glaciers showed a volume change of −0.71 ± 0.55 km3a−1, yielding a surface lowering of 0.52 ± 0.35 m a−1on average and an overall mass loss of 0.46 ± 0.37 m w.e. a−1. Highly variable individual glacier responses were observed and interestingly, they were less negative than previously reported for the neighboring Patagonian Icefields.
The Sorrentina Peninsula is a densely populated area with high touristic impact. It is located in... more The Sorrentina Peninsula is a densely populated area with high touristic impact. It is located in a morphologically complex zone of Southern Italy frequently affected by dangerous and calamitous landslides. This work contributes to the prevention of such natural disasters by applying a GIS-based interdisciplinary approach aimed to map the areas more potentially prone to trigger slope instability phenomena. We have developed the Landslide Susceptibility Index (LSI) combining five weighted and ranked susceptibility parameters on a GIS platform. These parameters are recognized in the literature as the main predisposing factors for triggering landslides. This work combines analyses conducted on Remote Sensing, Geo-Lithology and Morphometry data and it is organized in the following logical steps: i) Multi-temporal InSAR technique was applied to Envisat-ASAR (2003-2010) and COSMO-SkyMed (2013-2015) datasets to obtain the ground displacement time series and the relative mean ground velocity maps. InSAR allowed the detection of the areas that are subjected to ground deformation and the main affected municipalities; ii) Such deformation areas were investigated through airborne photo interpretation to identify the presence of geomorphological peculiarities connected to potential slope instability. Subsequently, some of these peculiarities were checked on the field; iii) In these deformation areas the susceptibility parameters were mapped in the entire territory of Amalfi and Conca dei Marini and then investigated with a multivariate analysis to derive the classes and the respective weights used in the LSI calculation. The resulting LSI map classifies the two municipalities with high spatial resolution (2m) according to five classes of instability. The map highlights that the high/very high susceptibility zones cover 6% of the investigated territory and correspond to potential landslide source areas characterized by 25°-70°slope angles. A spatial analysis between the map of the historical landslides and the areas classified according to susceptibility allowed testing of the reliability of the LSI Index, resulting in 85% prediction accuracy.
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Papers by Silvana Moragues