Surface velocity fields of active rock glaciers and ice‐debris complexes in the Central Andes of Argentina

Rock glaciers and transitional ice‐debris complexes predominate the Central Andean landform assemblage, yet regional studies on their state of activity and their kinematics remain sparse. Here we utilize the national glacier inventory of Argentina to quantify surface velocity fields of 244 rock glaciers and 51 ice‐debris complexes, located in the Cordón del Plata range, Argentina. Applying a feature‐tracking approach to repeated RapidEye satellite imagery acquired between 2010 and 2017/18, we find mean displacement rates between 0.37 and 2.61 m year−1 for 149 landforms, while for the remaining 146 features, surface movement remains below our level of detection. We compare our satellite‐derived velocity fields with ground‐truth data from two local field sites and find closely matching results in magnitude and spatial distribution. With average displacement of one‐third of the active rock glaciers and ice‐debris complexes exceeding 1 m year−1, the region hosts an exceptional number of fast‐flowing periglacial landforms, compared to other mountain belts. Using a random forest model, we test the predictive power of 25 morphometric and topoclimatic candidate predictors for modelling the state of activity of rock glaciers and ice‐debris complexes on two different scales. For entire landforms and individual landform segments, constructed along displacement centrelines, we can predict the state of activity with overall accuracies of 70.08% (mean AUROC = 0.785) and 74.86% (mean AUROC = 0.753), respectively. While topoclimatic parameters such as solar radiation and elevation are most important for entire landforms, geometric parameters become more important at the scale of landform segments. Despite tentative correlations between local slope and surface kinematics, our results point to factors integrating slope and distance to the source to govern local deformation. We conclude that feature tracking in optical imagery is feasible for regional studies in remote regions and provides valuable insight into the current state of the Andean cryosphere. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons LtdOur study quantifies the surface kinematics of 295 rock glaciers and ice‐debris complexes in the Central Andes using feature tracking in optical satellite imagery. We find nearly half of these are actively moving, with high average rates between 0.38 and 2.36 m year−1. Using a random forest modelling approach, we find topoclimatic predictors to have the highest importance for predicting the state of activity of entire landforms, while geometric predictors become more important on the scale of individual landform segments.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Deutsches Zentrum für Luft‐ und Raumfahrt http://dx.doi.org/10.13039/50110000294

Chapter 17: The future? Big questions about feedbacks between Anthropogenic change in the cryosphere and atmospheric chemistry

Anthropogenically driven changes in the cryosphere (mainly climate warming, but also land-use changes and increasing industrial and transportation activities) are changing how the cryosphere interacts with the atmosphere, which is, in turn, influencing the trajectory of further climate change. In particular, sea ice, snow, and permafrost exchange numerous climatically-active substances with the atmosphere, and the dramatic changes occurring in the distribution and physical-chemical characteristics of these ice environments have both regional and global implications. Some of these interactions are reasonably well understood, as documented in a number of the reviews in this book. However, many current and potential future feedbacks between the cryosphere and the atmosphere are very uncertain, and in some cases, even the net directions of the feedbacks are unknown. Big questions remain about, for example: how the rates of methane release versus oxidation are changing in warming marine and terrestrial environments; the contributions of cryospheric primary and secondary aerosols to global and regional atmospheric particle loads and cloud cover; whether, where, and when ecosystem changes are increasing or decreasing CO2 drawdown; and how changes in temperature and light interact in controlling chemical reactivity on ice surfaces, as well as driving adaptations in biological communities. Answering these questions will require not only hard work, but also creativity in conceiving and designing new research programs and developing new technologies. Particular challenges exist in developing robust, autonomous, in situ observation systems for deployment in harsh cryospheric environments and in integrating interdisciplinary information and ideas across wide time and space scales, from the molecular processes occurring at ice surfaces to the global climate system

Daily soil temperature and moisture records (2018-2019) from observation site GEC-1801 in the Argentinian Andes

Soil temperature (°C) and water saturation (%) were collected in the uppermost levels of the active layer from “El Candidato” rock glacier, from 2018 to 2019. “El Candidato” is an active rock glacier placed in the Argentinian Central Andes at 4012 m.a.s.l. (31.898672°S; 70.178486°W). The purpose of the data set was to analyze the volumetric water content and ground temperature variation in the landform frontal talus, in terms of active layer depth estimation. Four investigation depths were selected: 5 cm, 25 cm, 50 cm and 70 cm. Lectures were made 6 times a day, at 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours (GMT-3), from 17/04/2018 to 26/03/2019 with 4 SMT-100 data loggers (TRUEBNER GmbH, Germany). Soil temperature and water saturation were calculated as the average of the six daily data, considering for the last one site-specific porosity estimations

Daily soil temperature records (2019-2020) for active layer sites (GEC-1901 and GEC-1902) in the Argentinian Andes at 32°S

Soil temperature (°C) was collected in the uppermost levels of the active layer of “El Candidato” rock glacier, from 2019 to 2020. “El Candidato” is an active rock glacier placed in the Argentinian Central Andes at 4012 m a.s.l. (-31.898672°S; -70.178486°W). The purpose of the data set was to analyze the ground temperature in different pits, in terms of active layer depth estimation. The dataset includes the temperatures of two observation sites (GEC-1901 and GEC-1902) at different depths: 0 cm; 25 cm; 50 cm and 90 cm. The iButtons DS1922L (Maxim Integrated) took 6 measurements per day, at 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours (GMT-3), from 23/03/2019 to 02/03/2020. Soil temperature was calculated as the average of the six daily data

Propiedades insecticidas de la ceniza del complejo volcánico Puyehue-Cordón Caulle y su posible impacto ambiental

Se examina el efecto insecticida de las cenizas volcánicas en general y sus efectos ambientales, con especial énfasis en las cenizas acumuladas como consecuencia de la erupción del complejo volcánico Puyehue-Cordón Caulle, que actualmente afecta un área de más de 7,5 millones de hectáreas en la Patagonia Argentina. Se determinó la composición química de las cenizas provenientes del complejo Puyehue- Cordón Caulle por EDS, y se comprobó que los componentes mayoritarios son el O, Si, Al, Fe, Na y K. A través de bioensayos de laboratorio, utilizando dos especies de insectos como modelo biológico, se determinó que las cenizas se adhieren profusamente a la superficie corporal y resultan tóxicas para ambas especies cuando se mezclan con el sustrato en baja concentración. La susceptibilidad a las cenizas difirió entre ambas especies en bioensayos de siete días de exposición continua [CL99(Oryzaephilus surinamensis L.) = 10.25 mg.g-1; CL99((Tribolium castaneum (Herbst)) = 4.96 mg.g-1]. De estos resultados, se desprende que el impacto de la ceniza del complejo Puyehue- Cordón Caulle sobre la comunidad de artrópodos puede ser radical en la fase aguda de la deposición, y que sus efectos podrían ser substancialmente cualitativos en la fase crónica de la exposición. Así también, la recuperación de las poblaciones afectadas por la ceniza en las zonas con clima desértico, donde persiste la ceniza seca, será más lenta, hecho que tendrá consecuencias tangibles a largo plazo para las plantas hospederas de insectos, para la polinización y sobre el desarrollo de las poblaciones de vertebrados insectívoros. En contraste, en las regiones húmedas, la presencia de cenizas representa un cambio manifiesto en el ecosistema debido al aporte de nutrientes, que en combinación con la retención de agua por las cenizas, llevará a la recuperación cuali y cuantitativa de las poblaciones bajo condiciones favorables

Propiedades insecticidas de la ceniza del complejo volc\ue1nico Puyehue-Cord\uf3n Caulle y su posible impacto ambiental: Insecticidal properties of ashes from the volcanic complex Puyehue-Caulle Range and their possible environmental impact

Se examina el efecto insecticida de las cenizas volcánicas en general y sus efectos ambientales, con especial énfasis en las cenizas acumuladas como consecuencia de la erupción del complejo volcánico Puyehue-Cordón Caulle, que actualmente afecta un área de más de 7,5 millones de hectáreas en la Patagonia Argentina. Se determinó la composición química de las cenizas provenientes del complejo Puyehue-Cordón Caulle por EDS, y se comprobó que los componentes mayoritarios son el O, Si, Al, Fe, Na y K. A través de bioensayos de laboratorio, utilizando dos especies de insectos como modelo biológico, se determinó que las cenizas se adhieren profusamente a la superfi cie corporal y resultan tóxicas para ambas especies cuando se mezclan con el sustrato en baja concentración. La susceptibilidad a las cenizas difi rió entre ambas especies en bioensayos de siete días de exposición continua [CL99(Oryzaephilus surinamensis L.) = 10.25 mg.g-1; CL99 ((Tribolium castaneum (Herbst)) = 4.96 mg.g-1]. De estos resultados, se desprende que el impacto de la ceniza del complejo Puyehue-Cordón Caulle sobre la comunidad de artrópodos puede ser radical en la fase aguda de la deposición, y que sus efectos podrían ser substancialmente cualitativos en la fase crónica de la exposición. Así también, la recuperación de las poblaciones afectadas por la ceniza en las zonas con clima desértico, donde persiste la ceniza seca, será más lenta, hecho que tendrá consecuencias tangibles a largo plazo para las plantas hospederas de insectos, para la polinización y sobre el desarrollo de las poblaciones de vertebrados insectívoros. En contraste, en las regiones húmedas, la presencia de cenizas representa un cambio manifi esto en el ecosistema debido al aporte de nutrientes, que en combinación con la retención de agua por las cenizas, llevará a la recuperación cuali y cuantitativa de las poblaciones bajo condiciones favorables.<br>This paper discusses the insecticidal effect of volcanic ash and its environmental impact, focusing on the ash accumulated as a result of the eruption of the volcanic complex Puyehue- Caulle Range currently affecting an area of over 7.5 million hectares in the Argentine Patagonia. The chemical composition of ashes from the Puyehue-Caulle Range was analyzed by EDS showing that its major components are O, Si, Al, Fe, Na and K. Laboratory bioassays using two species of insects as a biological model, found that the ashes thoroughly adhere to the insect body surface and are toxic to both species tested, when mixed into the substrate at low concentrations. Susceptibility to ashes differs between the two species when tested in a seven day continuous exposure bioassay [CL99(Oryzaephilus surinamensis L.) = 10.25 mg.g-1; CL99((Tribolium castaneum (Herbst)) = 4.96 mg.g-1]. These results agree with those reported in the literature on effects of volcanic eruptions and suggest that the impact of the ashes from the Puyehue-Caulle Range volcanic complex on the insect community may be radical in the acute deposition phase, with substantial qualitative effects in the chronic phase of exposure. Also, the recovery of populations affected by ash in desert areas where dry ash persists will be slower, and this will have tangible and long-term consequences for insect host plants, pollination and on the development of populations of vertebrate insectivores. By contrast, the presence of ash in humid regions will impact the ecosystem by the addition of nutrients, which in combination with water retention by the ash will lead to a qualitative and quantitative recovery of the populations under favorable conditions