On the origin of the North Pacific arcs

We present a new hypothesis that relates global plate tectonics to the formation of marginal basins, island arcs, spreading ridges and arc-shaped mountain belts around the North Pacific Ocean. According to our model, the ellipsoidal-shaped Paleogene basins of the South China Sea, Parece-Vela Basin, Shikoku Basin, Sea of Japan and the Sea of Okhotsk in addition to those of the North American Cordillera can be attributed to the change in plate convergence direction at 42 Ma between the Indoaustralian and Eurasian plates. The new direction of convergence was parallel to the eastern continental margin of Asia and resulted in widespread extension perpendicular to this margin and to the western margin of North America. Both margins form part of a circle parallel to the Indoaustralian-Eurasian direction of convergence.

Combined use of the GGSFT data base and on Board Marine Collected Data to Model the Moho Beneath the Powell Basin, Antarctica

The Powell Basin is a small oceanic basin located at the NE end of the Antarctic Peninsula developed during the Early Miocene and mostly surrounded by the continental crusts of the South Orkney Microcontinent, South Scotia Ridge and Antarctic Peninsula margins. Gravity data from the SCAN 97 cruise obtained with the R/V Hespérides and data from the Global Gravity Grid and Sea Floor Topography (GGSFT) database (Sandwell and Smith, 1997) are used to determine the 3D geometry of the crustal-mantle interface (CMI) by numerical inversion methods. Water layer contribution and sedimentary effects were eliminated from the Free Air anomaly to obtain the total anomaly. Sedimentary effects were obtained from the analysis of existing and new SCAN 97 multichannel seismic profiles (MCS). The regional anomaly was obtained after spectral and filtering processes. The smooth 3D geometry of the crustal mantle interface obtained after inversion of the regional anomaly shows an increase in the thickness of the crust towards the continental margins and a NW-SE oriented axis of symmetry coinciding with the position of an older oceanic spreading axis. This interface shows a moderate uplift towards the western part and depicts two main uplifts to the northern and eastern sectors.

The Experience of European Integration and the Potential for Integration in South America

The experience of the European Union is the most significant and far-reaching among all attempts at regional integration. It is, therefore, the most likely to provide some lessons for those world regions that are just beginning this complex process. In turn, the Common Market of the South (MERCOSUR) and the Andean Community (CAN) are among the regional integration projects that have reached the greatest level of formal accomplishment after the EU. MERCOSUR is a customs union that aspires to become a common market, while avowing the commitment to advance towards political integration. For its part, CAN is a customs union that has already developed supranational institutions such as a Commission, a Parliament and a Court of Justice. In both cases, however, words have progressively tended to wander far from deeds. One reason underlying this phenomenon may be a misunderstanding of the European experience with integration. In this article, we discuss the theories that have been developed to account for integration in Europe and may prove useful to understand integration elsewhere and put forward a set of lessons that could be drawn from the European experience. Subsequently, we introduce a description of the experience of integration in South America and reflect (critically) on how the theories and lessons drawn from the EU could be applied to this region –and beyond.

The Evolution of the Climate Change Regime: Beyond a North-South Divide?

This research primarily analyses relevant climate bargaining dynamics that have been informed by a North-South impasse. This working paper argues that the first stage of negotiations for a climate convention indeed witnessed a North-South divide which became institutionalized in the Framework Convention on Climate Change. However, in subsequent negotiation rounds the key loci of bargaining struggles was centered between developed countries, in which relevant North-South cooperation dynamics were also present. Finally, this paper assesses the unfinished post-Kyoto bargaining process in which two trends are already being observed: both the emergence of a new geopolitics between the United States and major developing countries, and a fragmentation process within the South, in which the Copenhagen Accord itself has begun to institutionalize such fragmentation.

Taxonomic study of the isopod crustaceans from the Spanish expedition 'Antartida 1986-11' in the Scotia Sea, South Atlantic

This paper summarizes the results of a taxonomic study of the isopods collected during the 'Antártida 1986-11' expedition. A total of 123 specimens were studied, of which 99 were in the adult or juvenile phases and 24 were in the postmanca phase. The specimens were attributed to 11 species, 9 genera, 5 families and 4 suborders. The most abundant species were Glyptonotus antarcticus and Ceratoserolis trilobitoides. Several records are reported for the first time from the archipelagos of the Scotia Arc.

Changes in the foraging strategy of female South American sea lions (Carnivora: Pinnipedia) after parturition.

This study tests the hypothesis that female South American sea lions shift from off-shore, pelagic prey to coastal, benthic prey after parturition in order to reduce the foraging trip duration and hence the time pups remain unattended on the beach during early lactation. The δ13C and δ15N values of the serum and blood cells of 26 South American sea lion suckling pups from northern Patagonia were used to track the dietary changes of their mothers from late pregnancy to early lactation, after correction for differential isotopic fractionation between tissues. Primary producers and potential prey species were also analysed to establish a baseline for interpreting the stable isotope concentration of serum and blood cells. Isotopic ratios revealed a generalized increase in the consumption of coastal-benthic prey after parturition. Such a generalized post-partum shift will allow females to spend more time on land and look after their pups. The effects of this foraging strategy on the nutritional quality of the female"s diet are discussed.

Time and space: genetic structure of the common sea urchin paracentrotus lividus in the south-eastern iberian coast

Spatio-temporal variability in settlement and recruitment, high mortality during the first life-history stages, and selection may determine the genetic structure of cohorts of long-lived marine invertebrates at small scales. We conducted a spatial and temporal analysis of the common Mediterranean Sea urchin Paracentrotus lividus to determine the genetic structure of cohorts at different scales. In Tossa de Mar (NW Mediterranean), recruitment was followed over 5 consecutive springs (2006-2010). In spring 2008, recruits and two-year-old individuals were collected at 6 locations along East and South Iberian coasts separated from 200 to over 1,100 km. All cohorts presented a high genetic diversity based on a fragment of mtCOI. Our results showed a marked genetic homogeneity in the temporal monitoring and a low degree of spatial structure in 2006. In 2008, coupled with an abnormality in the usual circulation patterns in the area, the genetic structure of the southern populations studied changed markedly, with arrival of many private haplotypes. This fact highlights the importance of point events in renewing the genetic makeup of populations, which can only be detected through analysis of the cohort structure coupling temporal and spatial perspectives.

Local perception and use of the multifunctionality of water tanks in two villages of Tamil Nadu, South India

Using data from free listings and a survey in two villages of Tamil Nadu, India, we discuss local perceptions and uses of water tanks, a traditional irrigation infrastructure. We hypothesize that both farmers and nonfarmers perceive and use water tanks for purposes other than irrigation. We found that informants recognized the importance of water tanks for irrigation, but also acknowledged other socioeconomic uses and ecological functions. Marginal sectors (i.e., Scheduled Castes) use tank resources in more diverse ways than other sectors of the population. Findings are relevant for development. International organizations working on the revival of water tanks aim to transfer water management to farmers for the purpose of irrigation. By recognizing that tanks benefit people other than farmers and in ways other than providing irrigation water, organizations working on tank rejuvenation could achieve a more equitable management of tank resources.