scholarly journals Lithium and Brine Geochemistry in the Salars of the Southern Puna, Andean Plateau of Argentina

2020 ◽  
Vol 115 (5) ◽  
pp. 1079-1096
Author(s):  
Romina Lucrecia López Steinmetz ◽  
Stefano Salvi ◽  
Carisa Sarchi ◽  
Carla Santamans ◽  
Lorena Cecilia López Steinmetz
Keyword(s):  
South America ◽  
Regional Scale ◽  
Small Region ◽  
Easy Access ◽  
Northern Chile ◽  
Geographical Pattern ◽  
Hydrochemical Data ◽  
Puna Plateau ◽  
Brine Chemistry ◽  
Salt Pan

Abstract The Andean plateau is a small region of South America extending between northwest Argentina, southwest Bolivia, and northern Chile. It concentrates the largest global resources of lithium brines in its numerous salars. Of these, the giant salars in Bolivia and Chile have been relatively well studied; however, only little is known about the smaller but numerous salars in the Argentine Puna region. In this article, we present the results of the first regional-scale reconnaissance exploration of the 12 major salars situated in the southern part of the Puna plateau (24°S–26°30’S). Hydrochemical data indicate that the shallowest brines are characterized by highly variable Li concentrations, with mean Li grades ranging between 57 and 570 mg L−1, and mean Li/Mg ratios from 0.01 to 1.24. A survey of the brine chemistry of the salars across the Puna plateau, including its northern part, has revealed the absence of a geographical pattern in Li+ grade distribution. However, a comparison among mean Li+ grades, Li+/Mg2+ ratios, and the sizes of all salars allows an estimation of their Li mining potential. Specifically, the salt pan of Arizaro represents the highest potential, mainly due to its size; Antofalla-Botijuelas has a large surface and promising Li/Mg ratios for Li recovery via brine evaporation, though its elongated shape is a constraint; and Pastos Grandes, Pozuelos, and Rincón have encouraging Li grades, interesting salar sizes, and relatively easy access. Olaroz, Cauchari, and Hombre Muerto contain the highest Li+ grades in brines of the Argentine Puna and embody the most interesting perspectives of the Argentine plateau in a regional context. Salar sizes could be related to maximum Li+ grade of brines. Larger salars would then be expected to contain brines with higher Li+ grades than smaller ones, which could be considered as a useful criterion for surveys of brine-type deposits.

scholarly journals The Dry Puna as an ecological megapatch and the peopling of South America: Technology, mobility, and the development of a late Pleistocene/early Holocene Andean hunter-gatherer tradition in northern Chile

2017 ◽  
Vol 461 ◽  
pp. 41-53 ◽  
Author(s):  
Daniela Osorio ◽  
James Steele ◽  
Marcela Sepúlveda ◽  
Eugenia M. Gayo ◽  
José M. Capriles ◽  
...  
Keyword(s):  
South America ◽  
Late Pleistocene ◽  
Early Holocene ◽  
Northern Chile

scholarly journals Global horizontal irradiation: spatio-temporal variability on a regional scale in the south of the Pampeana region (Argentina)

2021 ◽  
Vol 56 (2) ◽  
pp. 220-233
Author(s):  
María Eugenia Fernández ◽  
Jorge Osvaldo Gentili ◽  
Ana Casado ◽  
Alicia María Campo
Keyword(s):  
South America ◽  
Seasonal Dynamics ◽  
Temporal Variability ◽  
Cloud Cover ◽  
Regional Scale ◽  
Temporal Distribution ◽  
The South ◽  
Monsoon System ◽  
Spatio Temporal ◽  
Dynamics Of Action

The objective of this work is to analyze the spatio-temporal distribution of Global Horizontal Irradiation (GHI) on a regional scale and its relationship with frequent synoptic situations in the south of the Pampeana region (Argentina). It was verified that the latitudinal pattern of distribution of the GHI is modified in the region by cloud cover, which is in turn determined by the seasonal dynamics of action centers and the passage of fronts in summer and winter. The South America Monsoon System (SAMS) defines differential situations of cloudiness and rainfall in the region, which affect GHI. GHI increased successively between the decades 1981–2010, a factor associated with the variability of rainfall that characterizes the region.

Structural evidence of the evolution of fore-arc basins off South America

1977 ◽  
Vol 14 (1) ◽  
pp. 102-116 ◽  
Author(s):  
W. T. Coulbourn ◽  
R. Moberly
Keyword(s):  
South America ◽  
Cross Sections ◽  
Seismic Reflection ◽  
Northern Chile ◽  
Oceanic Plate ◽  
Irregular Structure ◽  
Continental Block ◽  
The Face ◽  
Sediment Cover ◽  
Seismic Reflection Profiles

The continental margin of southern Peru and northern Chile was surveyed during the 1973 and 1974 expeditions of the research vessel Kana Keoki. Seismic reflection profiles reveal three large basins at about 1000 m depth between Mollendo, Peru (17°00′ S) and Iquique, Chile (20°00′ S). Only small basins and discontinuous terraces are seen on profiles crossing the Iquique-to-Antofagasta, Chile (23°30′ S) segment of the continental margin.The structural cross-sections of the basins resemble those of arc-trench gaps. The undeformed uppermost reflectors probably represent turbidites, as evidenced by displaced shallow-water benthic foraminifera and coarse sands in cores. Deeper reflectors are generally inclined land-ward, with dips and deformation increasing in the lower reflectors down to about 1.5 seconds penetration. Seaward convergence of these reflectors indicates a progressive shoreward migration of the axis of maximum sedimentation. If the deeper beds are also turbidites, this axis marks the axis of the sediment trap on the continental slope.The structure is consistent with subduction of an oceanic plate and obduction of a portion of its sediment cover. The imbricate stacking of obducted material is lifting an anticlinal ridge visible in most traverses across the trench side of the basin. The growing ridge is deforming the older sediment trapped in the upperslope basin and shifting the locus of deposition shoreward. The irregular distribution of the basins apparently is a product of culminations and depressions of the surfaces of imbricate fault planes. These undulations may result from the transference of the irregular structure of the oceanic plate to the face of the continental block.

scholarly journals Ancient DNA reveals the lost domestication history of South American camelids in Northern Chile and across the Andes

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Paloma Diaz-Maroto ◽  
Alba Rey-Iglesia ◽  
Isabel Cartajena ◽  
Lautaro Núñez ◽  
Michael V Westbury ◽  
...  
Keyword(s):  
South America ◽  
Formative Period ◽  
Archaeological Sites ◽  
South American ◽  
Northern Chile ◽  
Spanish Conquest ◽  
Domestic Species ◽  
South American Camelids ◽  
History Of ◽  
Early Formative

The study of South American camelids and their domestication is a highly debated topic in zooarchaeology. Identifying the domestic species (alpaca and llama) in archaeological sites based solely on morphological data is challenging due to their similarity with respect to their wild ancestors. Using genetic methods also presents challenges due to the hybridization history of the domestic species, which are thought to have extensively hybridized following the Spanish conquest of South America that resulted in camelids slaughtered en masse. In this study, we generated mitochondrial genomes for 61 ancient South American camelids dated between 3,500 and 2,400 years before the present (Early Formative period) from two archaeological sites in Northern Chile (Tulán-54 and Tulán-85), as well as 66 modern camelid mitogenomes and 815 modern mitochondrial control region sequences from across South America. In addition, we performed osteometric analyses to differentiate big and small body size camelids. A comparative analysis of these data suggests that a substantial proportion of the ancient vicuña genetic variation has been lost since the Early Formative period, as it is not present in modern specimens. Moreover, we propose a domestication hypothesis that includes an ancient guanaco population that no longer exists. Finally, we find evidence that interbreeding practices were widespread during the domestication process by the early camelid herders in the Atacama during the Early Formative period and predating the Spanish conquest.

scholarly journals Selective consumption of rodents by the Variable hawk Geranoaetus polyosoma (Accipitriformes: Accipitridae) in the Atacama Desert, northern Chile

2020 ◽  
Vol 37 ◽  
pp. 1-6
Author(s):  
Andrés Muñoz-Pedreros ◽  
Heraldo Norambuena ◽  
Claudia Gil ◽  
Jaime Rau
Keyword(s):  
South America ◽  
Trophic Ecology ◽  
Rattus Rattus ◽  
Atacama Desert ◽  
Rodent Species ◽  
Large Prey ◽  
Northern Chile ◽  
Desert Zone ◽  
Introduced Rodent ◽  
Prey Items

Geranoaetus polyosoma (Quoy & Gaimard, 1824) is a diurnal raptor widely distributed in South America. Although the trophic ecology of this bird has been more studied in the southern extreme of its range, little information is available on its dietary response to prey supply in desert environments. In the present study, we report on the trophic ecology of G. polyosoma in a sub-urban desert zone in northern Chile, with the following objectives: (1) to quantitatively describe its diet and (2) to determine its dietary selectivity in response to prey supply in the study area. The diet of G. polyosoma consisted mainly of rodents (97.2%). A greater preference (p < 0.05) was observed for the following large prey items (> 19.5 g): two native rodent species, Phyllotis xanthopygus (Waterhouse, 1837) and Eligmodontia puerulus (Philippi, 1896); and two introduced rodent species: Rattus rattus (Linnaeus, 1769) and R. norvegicus (Berkenhout, 1769).

scholarly journals Toward an open-access of high-frequency lake modelling and statistics data for scientists and practitioners. The case of Swiss Lakes using Simstrat v2.1

2019 ◽  
Author(s):  
Adrien Gaudard ◽  
Love Råman Vinnå ◽  
Fabian Bärenbold ◽  
Martin Schmid ◽  
Damien Bouffard
Keyword(s):  
Open Access ◽  
High Frequency ◽  
Thermal Structure ◽  
Regional Scale ◽  
Easy Access ◽  
Strong Wind ◽  
Long Term Effects ◽  
Output Data ◽  
Data Platform ◽  
Wind Events

Abstract. One-dimensional hydrodynamic lake models are nowadays widely recognized as key tools. They offer the possibility to study processes at high frequency, here referring to hourly time scale, to analyse scenarios and test hypothesizes. Yet, simulation outputs are mainly used by the modellers themselves and often not easily reachable for the outside community. We have developed an openly accessible web-based platform for visualization and promotion of easy access to lake model output data updated in near real time (https://simstrat.eawag.ch/). This platform was developed for 54 lakes in Switzerland with potential for adaptation to other regional areas or even at global worldwide scale using appropriate forcing input data. The benefit of this data platform is here practically illustrated with two examples. First we show that the output data allows for assessing the long term effects of past climate change on the thermal structure of a lake. In the second case, we demonstrate how the data platform can be used to study and compare the role of episodic strong wind events for different lakes on a regional scale and especially how they temporary destabilize their thermal structure. With this open access data platform we demonstrate the path forward for scientists and practitioners promoting a cross-exchange of expertise through openly sharing of in-situ and model data.

Evolution of data infrastructure for effective integration and management of environmental and ecosystem data

2020 ◽  
Author(s):  
Siddeswara Guru ◽  
Gerhard Weis ◽  
Wilma Karsdorp ◽  
Andrew Cleland ◽  
Jenny Mahuika ◽  
...  
Keyword(s):  
Web Services ◽  
Data Management ◽  
Management Practices ◽  
Regional Scale ◽  
Research Network ◽  
Easy Access ◽  
Ecosystem Research ◽  
Continental Scale ◽  
Data Products ◽  
Data Collections

<p>The Terrestrial Ecosystem Research Network (TERN) is Australia's national research infrastructure to observe, monitor and support the study and forecasting of continental-scale ecological changes. TERN data are classified under two themes: Ecology and Biogeophysical.</p><p> The Ecology theme relates predominantly to plot-based ecological observations conducted as a one-off, repeated surveys and sensor-based measurements. The Biogeophysical theme-related data collections are inclusive of point-based time-series eddy-covariance based micrometeorological measurements from flux towers; and continental and regional scale gridded data products related to remote sensing, soil and landscape ecology.</p><p>Integrating and querying data from different data sources are complicated. Furthermore,</p><p>The advancement of technology has transformed the mode of data collection. For instance, mobile sensors (drones) of various sizes are used more in recent times to sample the environment. The user-centric data handling mechanisms of different types of datasets are dissimilar, requiring heterogeneous data management practices alongside ease of access to data for users bundled with tools and platforms to interrogate, access, analyse and share analysis pipelines.</p><p>TERN is developing data e-infrastructure to support holistic capabilities that not only manage to store, curate and distribute data. But, enable processing based on user needs, linking consistent data to various analysis tools and pipelines and acquisition of data skills. The infrastructure would allow collaboration with other national and international data infrastructures and ingest data from partners including state and federal government institutes by adopting domain standards for metadata and data management and publications.</p><p>For effective data management of plot-based ecology data, we have developed an ontology-based on O&M and Semantic Sensor Network Ontology with an extension to support basic concepts of ecological sites and sampling. Besides, controlled vocabularies for observed properties, observation procedures and standard lists for taxa, geology, soils etc. will supplement the ontology.</p><p>The biogeophysical data is managed using domain standards in the data and metadata management. Each of the data products is represented in a standard file format and hosted in an OGC standard web services. All datasets are described and catalogued using ISO standards. An overarching discovery portal allows users to search, access and interact with data collections. The user’s interaction with data can be at the collection level, on a spatial map and via web services and Application Programming Interface (API).</p><p>TERN has also developed a cloud-based virtual desktop environment, CoESRA, accessible from a web browser to enable easy access to the computing platform with tools for the ecosystem science community. The advantage is that it allows access to all TERN data in a compute environment for performing analysis and synthesis activities from a single managed platform.</p>

scholarly journals Regional drought in the southern of South America: physical aspects

2010 ◽  
Vol 25 (1) ◽  
pp. 88-102 ◽  
Author(s):  
Juan Leonidas Minetti ◽  
Walter Mario Vargas ◽  
Arnobio German Poblete ◽  
Maria Elvira Bobba
Keyword(s):  
South America ◽  
Atmospheric Pressure ◽  
Regional Scale ◽  
Atmospheric Temperature ◽  
Sea Surface ◽  
Brazilian Coast ◽  
Subtropical Anticyclone ◽  
Central Chile ◽  
The Pacific ◽  
Regional Drought

From the indices of monthly and annual climatic drought in six regions in southern South America and their associations with seventeen predictors, the probable physical causes of droughts are analyzed. These indices are used in operational climate monitoring and describe the atmospheric temperature and sea surface temperature (SST) near South America. Subtropical anticyclone activity over both coasts of South America is one of the main predictors, together with its interaction with the continental depression and SST at the coast of Brazil. The highest predictability concentrates in November-December-May and the lowest in March, June and August. In the sub regional scale, the main predictors respond to atmospheric pressure anomalies in the Atlantic Ocean for Argentinean Northwest (NOA), SST in the Brazilian coast for Argentinean Northeast (NEA), anticyclonic conditions over the Pacific and Atlantic for the Central West (CO), the latter and their interaction with the continental depression for Humid Pampa (PH), anticyclonic activity over the Pacific for the Patagonia (PAT) and trans cordillera circulation for Central Chile and Comahue (CHI).

scholarly journals MONITORING GROUNDWATER STORAGE IN NORTHERN CHILE BASED ON SATELLITE OBSERVATIONS AND DATA SIMULATION

2016 ◽  
Vol 22 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Henry C. Montecino ◽  
Guido Staub ◽  
Vagner G. Ferreira ◽  
Luis B. Parra
Keyword(s):  
Scale Validation ◽  
Regional Scale ◽  
Temporal Variations ◽  
Public Works ◽  
Metropolitan Region ◽  
Northern Chile ◽  
Regional Study ◽  
Groundwater Storage ◽  
The North ◽  
Snow Storage

Groundwater is one of the most valuable sources of fresh water in many places worldwide, especially in regions with low pluviometric indices such as northern Chile. Thus, it is mandatory to monitor this precious resource in space and time domains. Currently, groundwater in Chile is monitored using sparse stations of water table observations. Although other indirect alternatives such as space-borne observations can contribute to regional understanding of groundwater variations, they have been poorly studied in Chile. In this study, groundwater monitoring is carried out based on 104 monthly solutions of the Gravity Recovery and Climate Experiment (GRACE) mission between 2004 and 2013. The extraction of the groundwater storage (GWS) signal obtained from GRACE was recovered once the effects of soil moisture and snow storage, retrieved from the Global Land Data Assimilation System (GLDAS), were removed. Analysis of the data was performed point-wise (six stations) and at regional scale (Northern Chile). Overall, the results are correlated with wells observations obtained by the General Directorate of Water Resources (DGA) of the Ministry of Public Works of Chile. Point-wise comparison shows root mean square error (RMSE) large than 30.0 mm while regional scale validation shows RMSE of 21.5 mm. Furthermore, regional groundwater variations obtained from GRACE/GLDAS are highly consistent in terms of trend with results obtained from well observations in the DGA network. The Empirical Orthogonal Function (EOF) analysis revealed higher annual groundwater variability in the metropolitan region and a higher inter-annual variability in the north. The methodology used may contribute to the regional study of spatial-temporal variations of groundwater in regions with sparse hydrometric network

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