Argentine Side Research Articles

Argentina vs Great Britain: the trajectory of one conflict

40 years ago, on April 2, 1982, Argentina made a failed attempt by military means to establish sovereignty over the archipelago in the South Atlantic, which was under the jurisdiction of Great Britain. The war was the result of a two-century dispute over the ownership of the islands. Upon joining the UN in 1945, Buenos Aires loudly announced its claims to the Falkland Islands (Malvinas) and began to seek from the international community to recognize its claims as legitimate. Since then, the problem has been a red thread through the history of the country. The policy of the Argentine authorities on the issue of disputed territories developed with a pendulum dynamic. Periods of de-escalation of the conflict and the development of cooperation with Great Britain, coupled with a friendly attitude towards the islanders, were replaced by phases of the dominance of irreconcilable discourse with a strong demand for the “termination of the colonization policy” by the British authorities. Relations between Argentina and Great Britain after the end of hostilities can be divided into several stages. Regardless of the direction of the course of the next government, the issue of sovereignty over disputed territories has never been removed from the agenda. The Argentine side certainly used the “Malvinas question” as an instrument of domestic policy. Currently, the conflict is in a latent phase with no prospect of an early resolution.

An approach of the state in/from its national borders: the case of the argentine side of the Tri-Border Area of Paraná

Resumen El presente artículo resulta de las discusiones sobre la perpetuada idea de estado y el empleo del método etnográfico en el estudio sobre los agentes y las instituciones estatales. Para ello se tomaron en cuenta las prácticas estatales de control fronterizo que formaron parte del proceso de cierre de fronteras llevado a cabo por agentes e instituciones que se encuentran nucleados en el Centro de Frontera Iguazú, ubicado en el lado argentino de la región transfronteriza de la Triple Frontera del Paraná. El escrito tiene un posicionamiento teórico que hace uso de la noción del estado nación como abstracción discursiva, pero, por otro lado, teniendo en cuenta que se (con)forma y se materializa por agentes e instituciones articulados entre sí, que presentan sus propias particularidades a su interior. Esto genera una ruptura con las nociones estáticas que llegan a considerar al estado como una entelequia omnipresente y homogénea.

Functional response of benthic macroinvertebrates to fire disturbance in patagonian streams

Disturbances often act as ecological filters through which only certain combinations of biological traits may pass. Here, we aimed to determine if an unprescribed human-started wildfire can act as a filter for stream-dwelling macroinvertebrates. To do this, we sampled three burnt and two reference streams in Los Alerces National Park (Patagonia, Argentine side). Sampling began shortly after the fire was extinguished and comprised four visits during the following seven months. We explored how functional richness, evenness, and dispersion at the community level responded to post-fire environmental changes using generalized linear mixed models. We also used RLQ and fourth-corner analysis to identify which trait modalities were specifically affected, either positively or negatively, by the fire. We found that functional richness and dispersion decreased with increasing disturbance intensity, which in this case, was best represented by increased suspended solids. In addition, all three functional metrics were significantly lower in fire-affected sites. Burnt streams were characterized by bi-multivoltine taxa and collector-gatherers, among others. Overall, our study showed how a wildfire can directly constrain the functional composition of macroinvertebrate communities, and highlighted the importance of incorporating trait-based approaches into the study of large-scale disturbances.

Geomorphology of the northeastern extreme of Isla Grande de Tierra del Fuego, Argentina

ABSTRACT A 1:60,000 scale geomorphological map of the Argentine side of the northeastern extreme of Isla Grande de Tierra del Fuego in southernmost South America is presented. This paper describes and summarizes the geomorphology of the mapped area, which includes glacial, periglacial, fluvial, coastal, aeolian, lacustrine, and anthropogenic landforms that span over 680 km2 north of San Sebastián Bay in a sparsely populated semiarid and cold steppe used for sheep breeding and hydrocarbon extraction. We used Landsat-8, Sentinel-2, and ALOS-PALSAR satellite products combined with field validation to create the map. Glacial advances and retreats as well as climatic and sea level fluctuations that controlled fluvial systems and coastal dynamics were the main sculptors of the landscape during the Late Cenozoic. Aeolian, lacustrine, and anthropogenic activity were later minor contributors. The presented free, open access, vector geomorphological map is intended to be a supporting tool for multidisciplinary researchers and decision-makers.

Structural and petrographic constraints on the stratigraphy of the Lapataia Formation, with implications for the tectonic evolution of the Fuegian Andes

The structure of the Fuegian Andes central belt is characterized by a first phase of peak metamorphism and ductile deformation, followed by a brittle-ductile thrusting phase including juxtaposition of different (first phase) structural levels; both related to the closure and inversion of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The second phase involved thrust sheets of pre-Jurassic basement, as well as Upper Jurassic and Lower Cretaceous units from the volcanic-sedimentary fill of the basin. Rock exposures in the Parque Nacional Tierra del Fuego reveal a diversity of metamorphic mineral assemblages, dynamic recrystallization grades and associated structures, evidencing a variety of protoliths and positions in the crust during their orogenic evolution. Among the units present in this sector, the Lapataia Formation portrays the higher metamorphic grade reported in the Argentine side of the Fuegian Andes, and since no precise radiometric ages have been established to date, its stratigraphic position remains a matter of debate: the discussion being whether it belongs to the pre-Jurassic basement, or the Upper Jurassic volcanic/volcaniclastic initial fill of the Rocas Verdes basin. The mapping and petrographic/microstructural study of the Lapataia Formation and those of undoubtedly Mesozoic age, allow to characterize the former as a group of rocks with great lithological affinity with the Upper Jurassic metamorphic rocks found elsewhere in the central belt of the Fuegian Andes. The main differences in metamorphic grade are indebted to its deformation at deeper crustal levels, but during the same stages than the Mesozoic rocks. Accordingly, we interpret the regional structure to be associated with the stacking of thrust sheets from different structural levels through the emplacement of a duplex system during the growth of the Fuegian Andes.

Alteration of hydrogeomorphic processes by invasive beavers in southern South America

The North American beaver (Castor canadensis) is an invasive species in southern Patagonia, introduced in 1946 as part of a program by the Argentine government to augment furbearers. Research focus has turned from inventorying the beaver's population and ecosystem impacts toward eradicating it from the region and restoring degraded areas. Successful restoration, however, requires a fuller determination of how beavers have altered physical landscape characteristics, and of what landscape features and biota need to be restored. Our goal was to identify changes to the physical landscape by invasive beaver. We analyzed channel and valley morphology in detail at one site in each of the three major forest zones occurring on the Argentine side of Tierra del Fuego's main island. We also assessed 48 additional sites across the three forest biomes on the island to identify a broader range of aquatic habitat occupied and modified by beaver. Beaver build dams with Nothofagus tree branches on streams, which triggered mineral sediment accretion processes in the riparian zone, but not in ways consistent with the beaver meadow theory and only at a few sites. At the majority of sites, beavers actively excavated peat and mineral sediment, moved thousands of cubic meters of sediment within their occupied landscapes and used it to build dams. Beaver were also common in fen ecosystems where pond formation inundated and drowned peat forming mosses and sedges, and triggered a massive invasion of exotic plant species. Results highlight that restoration of fen ecosystems is a previously unrecognized but pressing and challenging restoration need in addition to reforestation of Nothofagus riparian forests. We recommend that decision-makers include the full ecosystem diversity of the Fuegian landscape in their beaver eradiation and ecosystem restoration plans.

Validation of neutronic models and calculation systems by means of experimental results in the IPEN/MB-01 reactor

In the year 2008 the National Atomic Energy Commission (CNEA) of Argentina, and the Brazilian Institute of Energetic and Nuclear Research (IPEN-CNEN/SP), under the framework of the Nuclear Energy Argentine-Brazilian Agreement (COBEN), among other projects, included “Validation and Verification of Calculation Methods used for Research and Experimental Reactors”. At that time, it was established that the validation was to be performed with models implemented in the deterministic codes HUEMUL and PUMA (respectively, cell and reactor codes) developed by CNEA and those implemented in MCNP5. The necessary benchmark data for these validations would correspond to the theoretical–experimental reference cases elaborated in the research reactor IPEN/MB-01 located in the city of São Paulo, Brazil. These benchmarks were previously evaluated and approved for publications in the ICSBEP and IRPhE handbooks. The staff of the Nuclear Design and Analysis Division of the Reactor and Nuclear Power Plant Study Department (ERC) of CNEA, from the argentine side, modeled and performed several calculations with both deterministic (HUEMUL-PUMA) and probabilistic (MCNP5) methods of a great number of physical situations of the reactor, which previously have been studied experimentally and modeled by members of the Nuclear Engineering Center of IPEN, whose results were extensively provided to CNEA. The analyses reveal the great performances of ENDF/B-VII.0 in conjunction with MCNP5 and the HUEMUL and PUMA codes in all benchmark applications.

Analizando la variabilidad del registro arqueológico en sociedades cazadoras-recolectoras desde la etnoarqueología

From 1986, our research projects in Isla Grande of Tierra del Fuego, in collaboration with other Argentinian team, have emphasized the goal of develo- ping a methodology for a proper archaeological recog- nition of the social organization from archaeological evidence. The work presented here focuses on one of the settlements excavated during these projects, VII T unnel, located on the Argentine side of the Isla Grande of T ie- rra del Fuego. The site is highly representative of the canoe societies of the fueguian channels, at least in its final phase. The excavation method allow us to recogni- ze the detailed sequence of a series of at least ten discre- te episodes of occupation, over a century, which took pla- ce in almost all the seasons. The Tunnel VII moments of occupation do not carry specific seasonal patterns linked. Livelihood strategies are highly specialized but flexi- ble that are not represented in the conceptual dual co- llector or forager, ie specialization in non-specia- lization. The same evidence has served to set clear and defining general behavior regarding the use of space.

Quaternary evolutionary history of Austrocedrus chilensis, a cypress native to the Andean–Patagonian forest

AimThe Quaternary life history of a species determines its current range and the degree and distribution of its present genetic variation. Past climates, ecological relationships and disturbances in connection to evolutionary factors have determined the genetic and geographical distribution patterns of the current vegetation, and consequently, evolutionary processes can be inferred from those patterns. The aim of the present study is to find a plausible evolutionary explanation for the current natural range and genetic variation patterns of Austrocedrus chilensis (D. Don) Florin et Boutelje in Argentina.LocationThe studied species ranges naturally over a narrow strip not wider than 50 km that runs parallel to the Cordillera de los Andes from 32°39′ S in Chile to 43°44′ S in Argentina. The studied populations are located in the Argentine range, especially in its central part.MethodsInformation on palynological data, current geographical distribution and on amount and distribution of genetic variation of the species in Argentina was the basis for an integrating analysis and discussion.ResultsPalynological evidence of the past reported the presence of A. chilensis before and immediately after last glaciation on the east side of the Andes. The most conspicuous present populations of A. chilensis are located in areas that were covered by ice during the Last Glacial Maximum. The allelic multiplicity and diversity as well as the population differentiation of the species in Argentina were shown to be small, while the levels of heterozygosity were moderate. A latitudinal gradient trend was recognized as a pattern of distribution of variation in Argentina, the northerly populations being more variable. Extreme marginal populations located in the steppe, out of the glaciated area, show the greatest levels of variation.Main conclusionsEvidence was shown supporting that the major factor responsible for the variation pattern found in A. chilensis were the glacial processes. In the Argentine side of the Cordillera de los Andes the species could survive only in a narrow strip between the coldness of the ice sheet and the dryness of the steppe. That implies a generalized genetic drift process. Multiple small refuges in the eastern side of the Cordillera are hypothesized where this cypress would have survived to glaciation. Those refuges are postulated to have been chiefly localized slightly eastward to the present distribution area and most probably in a northern location, at least from 42°S of latitude to the north.

Legal Situation of British Property in Argentina: a report prepared by the Centre for South Atlantic Studies (Buenos Aires)*

In April 1982, when hostilities broke out between the Argentine Republic and Great Britain, both Governments imposed severe reciprocal restrictions upon the assets of their respective citizens and residents. In particular, all financial movements relating to trade were blocked. On the Argentine side, thefirst measures were announced through communiques from the Central Bank, which were systematized shortlyafterwards by Decrees 683/82, 786/82 and 787/82, and supplemented by various Central Bankresolutions, as well as resolutions from the Ministries of Economy, Defence, Public Works, the Energy Secretariat, the National Customs Administration and the Under Secretariat of Economy. Specifically, thelast named did so by Resolution No. 99/82 (published in the ‘Boletin Oficial’ of 10 May 1982) which suspended ‘temporarily’ the registration of transfers of shares in local companies belonging to investors who — according to the Registry of Foreign Investments — were resident or domiciled in the United Kingdom.

Two Patagonian basins - Negro (Argentina) and Valdivia (Chile) - as habitats for Plecoptera

Even though the insects of the Neotropical area had been neglected, several authors have studied different aspects of the Southern Neotropical Plecoptera (Aubert, Benedetto, Enderlein, Froehlich, Gerstaecker, Illies, Navás, Klapálek, Werner, Zwick), specially the Andean oligostenothermal cool-adapted stoneflies. Most of the Argentinian river basins are widely spread out. The upper reaches of the Negro hydrographic system are on the east slope of the Andes and discharge into the Limay and Neuquén rivers downstream. The Negro river is formed by the convergence of both rivers and presents a sequence of reservoirs (main-stream impoundments on Limay and off-channel ones at Neuquén) ; it reaches the South Atlantic coast at approximately 41 ° S. The headstreams of the Valdivia system are on the west slope of the Andes. This river, much shorter than the Negro, joins the Pacific at 40° S. Transition from rhithron to potamon is rapid, if indeed the potamon exists. Macrozoobenthic samples of these two North Patagonian river basins, Negro (Argentina) and Valdivia (Chile) were taken in the period 1977-1983 in order to compare habitats of aquatic insects and other invertebrates on both slopes of the Andes and at the same latitude. Ten genera of Plecoptera were recorded by the author as nymphs : Gripopterygidae (Antarctoperla, Limnoperla, Potamoperla, Pelurgoperla, and Araucanioperla ?), Diamphipnoidae (Diamphipnoa and Diamphipnopsis), Austroperlidae (Klapopteryx), Notonemouridae (Austronemoura) and Perlidae (Kempnyella). Most of these genera of Plecoptera were collected in the upper rhithral. Only Antarctoperla and Limnoperla were found in reservoirs, in one lake and in medium-size to wide rivers. Gripoperygids were more frequent on the Argentine side ; the other families were more abondant on the opposite slope ; this situation can probably be explained by the different ecological conditions brought about by cattle raising and dam construction.

Ocean Voyaging under Sail

When advancing years put the Himalaya out of reach my thoughts turned to sailing and the chances of combining this with climbing, two activities that have much in common. After an apprenticeship in the form of two voyages with Bobby Somerset—whom I still regard as the maestro in small boat matters—I acquired Mischief solely with a view to crossing the Patagonia ice-cap. The ice-cap had not then been crossed and since all attempts from the Argentine side had failed I thought of tackling it from the sea. Mischief, 45 ft. long, 13 ft. beam, 7 ft. 6 in. draught, of about 30 tons T.M., had been built in 1906 as a Bristol Channel pilot cutter.

The Patagonia Ice Cap

There are few places in the world where a man can sail to the foot of his climb. One such place is the southernmost coast of Chile where the glaciers come down into the sea. It is a region, therefore, which has a powerful attraction for a mountaineer who late in life catches sea fever and aspires to making a long ocean voyage with some mountains at the end of it. Such was the germ of an idea which led me to attempt a crossing of the Patagonia ice cap. On the i: i million sheets of southern Chile compiled by the American Geo? graphical Society are two white spaces, more or less blank, marked inesplorado. These are the northern and southern portions of the ice cap, divided by the Rio Baker and extending from lat. 440 S. to lat. 510 30' S. The ice cap varies in height from 6000 to 10,000 feet, and in width from 15 to 50 miles. The highest mountain on it is San Valentino at the northern end (13,345 feet), which was climbed for the first time in 1953. It is the largest glaciated region of the temperate zone. Its northernmost glacier, the San Rafael, reaches the sea in lat. 46?4o'S., farther from the pole than any Alaskan glacier by 10 degrees, and fully 20 degrees farther than the Jokelfjord, the most southern of the Norwegian glaciers which reach the sea. Darwin pointed out that this San Rafael glacier, 15 miles long and in one place 7 miles wide, pushes its ice into the sea at a point on the coast where, within less than 500 miles, palms grow. The boundary between Chile and Argentina follows roughly the crest line of the Cordillera and all previous exploration has been from the Argentine side. Since 1914 many attempts to cross the ice cap have been made. It is reported that in 1954 an Argentine expedition led by a Major Huerta did succeed in crossing from Lake Argentino to the Pacific, but so far I have not been able to obtain any detailed infor? mation it. On the Argentine side there are many glaciers which descend into the great lakes of Buenos Aires, Viedma, and Argentino, and there are estancias near the shores of these lakes. On the Chilean or Pacific side, where the weather is much less favourable, the glaciers descend to the waters of deep, narrow fjords, and there is nothing but ice, rock, and tangled rain forest. For nearly 1000 miles northwards from Punta Arenas the coast and the hundreds of islands are uninhabited. The Admiralty Pilot describes it as about as inhospitable a land as is to be found in the globe. The land is mountainous, presenting an alternation of matted forest, bare rock, and deep bogs, and is intersected by many deep channels into peninsulas and islands as yet very imperfectly known. The scenery is magnificently stern; cloud and mist usually screen the higher peaks and snow fields. Early in 1954 I acquired a boat suitable for this venture, an ex-Bristol Channel pilot cutter called Mischief, built in 1906. She measured 45 feet overall, 13 feet beam, and drew 7 feet 6 inches aft, with a displacement of 50 tons. Of the attempt made that year the less said the better. We fitted out at Palma, Mallorca, where I had bought the boat, and upon reaching Gibraltar in late August the crew melted away, leaving me to consider how to get the boat home and to ponder the truth of the Chinese sage's remark that discord is not sent down from heaven; it is brought by women. In 1955 I had great difficulty in raising a crew. Finally it consisted of W. A. Procter, a retired Civil Servant who knew something