Thermal waters of ‘tectonic origin’: the alkaline,Na‐HCO3 waters of the Rio Valdez geothermal area (Isla Grande de Tierra del Fuego,Argentina)

The geothermal area of Rio Valdez is located in the central portion of the Isla Grande de Tierra del Fuego (South Argentina), ten kilometers south of the southeastern sector of the Fagnano Lake. It consists of a series of thermal springs with low discharge rates (≤1 L/s) and temperatures in the range of 20–33°C distributed in an area of <1 km². The thermal springs are characterized by alkaline, Na‐HCO₃ waters with low salinity (0.53÷0.58 g/L), but relatively high fluoride contents (up to 19.4 mg/L). Their composition is the result of a slow circulation at depth, possibly through deep tectonic discontinuities connected with the Magallanes‐Fagnano Fault (MFF) system. According to geothermometric calculations, thermal waters reach temperatures in the range of 100–150°C and an almost complete chemical equilibrium with the alkali‐feldspars in the metavolcanic country rocks. The relatively high fluorine contents can be explained by the slow ascent and cooling of deep groundwaters followed by a progressive re‐equilibration with F‐bearing, hydrated Mg‐silicates, such as chlorite, which has been recognized as an abundant mineral in the metavolcanics of the Lemaire Formation and metapelites and metagraywackes of the Yahgán Formation. Finally, the isotopic composition of the investigated samples is consistent with the infiltration from local snow melting at altitudes in the range of 610–770 m asl. The comparison of our data with those collected in 1991 seems to suggest a possible progressive decline of the bulk thermal output in the near future. This possibility should be seriously considered before planning a potentially onerous exploitation of the resource. Presently, the only ways to exploit this geothermal resource by the population scattered in the area are the direct use of thermal waters and/or spa structures.     

Coupling Hydrotoponymy and GIS Cartography: A Case Study of Hydrohistorical Issues in Urban Groundwater Systems,Porto, NW Portugal

The aim of this multidisciplinary study is to retrospectively examine hydrohistorical issues, namely hydrogeographic, hydrotoponymical and hydrogeological features, in order to assess the evolution of the Porto urban groundwater system (NW Portugal). To achieve these goals, the comparison of two main field inventories in a large urban region was performed by (i) historical mapping of sources and groundwater data from scientific reports spanning the late 17th century to the early 20th; and (ii) hydrogeologic and hydrotoponymical field inventory performed under current conditions. These field inventories permitted the location of springs, dug wells, fountains, public washing places and underground water galleries, which collected groundwater to supply the population of Porto until the early 20th century. This study also allowed the development of a hydrotoponymical classification for urban areas and a field hydrotoponymical inventory data sheet. This research integrated several techniques based on historical hydrogeography, hydrogeology and urban geosciences. The results of the field inventories were combined into both a database and a Geographical Information System (GIS) platform. This unified methodology allowed a cross‐check and analysis of several levels of information, namely hydrotoponymy, hydroclimatology, hydrogeology, structural geology and geomorphology. This perspective led to an assessment of the evolution of the quality of water resources in large urban areas over time. In addition, the role of hydrotoponymical features is presented in order to support the hydrogeological conceptual model for large urbanised areas.     

Human security and development in Africa

There has been a recent rise in optimism about Africa's prospects: increased economic growth; renewed regional and national political commitments to good governance; and fewer conflicts. Yet, given current trends and with less than eight years until 2015, Africa is likely to fail to meet every single one of the Millennium Development Goals (MDGs). Home to almost one‐third of the world's poor, Africa's challenges remain as daunting as ever. Despite highly publicized increased growth in some economies, the combined economies of Africa have, on average, actually shrunk and are far from meeting the required 7 per cent growth needed to tackle extreme poverty. A similar picture emerges from the analysis of Africa's performance on the other MDGs. In a world where security and development are inextricably connected in complex and multifaceted ways, Africans are, as a result, among the most insecure. By reviewing a select number of political, security and socio‐economic indicators for the continent, this analysis evaluates the reasons underlying Africa's continuing predicament. It identifies four critical issues: ensuring peace and security; fostering good governance; fighting HIV/ AIDS; and managing the debt crisis. In assessing these developmental security challenges, the article recalls that the MDGs are more than time bound, quantified targets for poverty alleviation–they also represent a commitment by all members of the international community, underwritten by principles of co‐responsibility and partnership, to an enlarged notion of development based on the recognition that human development is key to sustaining social and economic progress. In recent years, and often following failures, especially in Africa, to protect civilian populations from the violence and predation of civil wars, a series of high‐level commissions and expert groups have conducted strategic reviews of the UN system and its function in global politics. The debate has also developed at the theoretical level involving both a recon‐ceptualization of security, from state centred norms to what is referred to as the globalization of security around the human security norm. There has also been a reconceptualization of peacekeeping, where the peacekeeping force has enough robustness to use force not only to protect populations under the emergent responsibility to protect norm, but also enough conflict resolution capacity to facilitate operations across the conflict–development–peacebuilding continuum. This article opens up a discussion of how these ideas might be relevant to security regime building and conflict resolution in African contexts, and suggests how initiatives in Africa might begin to make a contribution to the theory and practice of cosmopolitan peacekeeping.     

CONCEPTUAL DESIGN OF ISOLATION SYSTEMS FOR BRIDGE STRUCTURES

Abstract

In the first part of this paper the objectives of an isolation system for a bridge structure are discussed, in relation to modelling options and modification of the traditional capacity design principles. A displacement-based design approach is then presented, using a linear equivalent single degree-of-freedom model. The preliminary design of an isolation system for existing bridges is based on the definition of a “structure regularity” which allows the estimation of whether the response of the real structure will be similar to that predicted in the preliminary design phase. The efficiency of the approach is shown in designing the isolation system for a highly irregular bridge.     

Humiliating the Brazilian poor: The iconoclasm of former president Lula

Circulating in Brazil's social media today are many vicious attacks against presidential candidate Luiz Inácio Lula da Silva, known simply as Lula. Widely and enthusiastically shared memes humiliate Lula by depicting him as a poor, uneducated drunkard who deserves to be in jail, thus criminalizing his class background and political biography. What do the memes and conversations reveal about the roots of this aggression against him? Brazil has been plagued by a large corruption scandal called ‘Operation Car Wash’, for which many hold Lula partly responsible. The attacks are also an attempt to discredit Lula as a presidential candidate, which has placed his candidacy in the balance. But the memes also suggest a deep and genuine fear of poverty and the poor, which is related to fragile consumer‐oriented class relations. The iconoclasm of Lula and the destruction of his dignity reflect this anguish. The memes serve to create a symbolic line between ‘us’ – the ‘middle class’, the ‘good people’ (pessoas do bem) – and ‘them’ – the poor, who are depicted as immoral drunkards who have no dignity.