Les premières migrations ont atteint la région de l’Océanie Lointaine (à l'est des îles Salomon) récemment, autour de 3000 ans BP. De nombreux éléments sont à prendre en compte dans ce processus de déplacement de populations, dont les changements environnementaux. L’installation de l’Homme sur des îles vierges a probablement influencé la faune et la flore insulaires, mais la réponse de la végétation face à la pression anthropique varie d’un site étudié à un autre. Les objectifs de cette recherche ont été de décrire l'influence humaine sur l'environnement depuis les premières migrations, de déterminer l'impact climatique sur ces déplacements de populations et sur la modification des paysages au cours de l'Holocène supérieur ; puis, de caractériser le comportement humain et son adaptation à une île vierge. Pour répondre à cette problématique, deux carottes palustres, prélevées sur l'île d'Efate (au centre du Vanuatu) ont été étudiées : le marais d’Emaotfer et le lac Otas. Afin d’identifier la paléovégétation arborée et herbacée présente autour des sites, j’ai principalement analysé les grains de pollen et les micro-charbons. J’ai également reconstitué les températures et les précipitations passées à l’aide de fonctions de densité de probabilité.Au niveau climatique, ces analyses mettent en évidence une période chaude et humide jusqu'à 3700 ans cal BP. Ensuite, un environnement plus sec se met en place, suite à une augmentation de l'ampleur et du nombre d’évènements El Niño. Entre 1950 et 750-600 ans cal BP, les résultats révèlent un climat plus humide, associé à la diminution de fréquence et d’intensité des El Niño. Les modifications de la végétation du marais d’Emaotfer et du lac Otas illustrent une nouvelle période sèche après 750-600 ans cal BP, que l’on peut associer au Petit Âge Glaciaire.Les populations Lapita ont atteint l'île d'Efate vers 3000 ans cal BP, sous des fréquents et importants El Niño, lorsque les vents d'est se sont arrêtés, favorisant la navigation à voile vers l’est. Ces résultats soutiennent l'hypothèse de migrations vers l'est sous de faibles alizés. Les premiers colons étaient des navigateurs et des pêcheurs-cueilleurs, ils ont eu peu d'impact sur l'environnement. Autour de 1500-1300 ans cal BP, une nouvelle population s’est installée sur le site d’Emaotfer, a développé la culture de plantes médicinales, cérémoniales et alimentaires et a probablement pratiquée l’agriculture sur brûlis. Ce groupe a vécu sous un climat humide, également plus approprié au développement de l'horticulture. Nos résultats montrent la capacité d'adaptation des populations aux nouvelles contraintes environnementales et climatiques. Les résultats issus des analyses polliniques et de micro-charbons livrent des informations assez complètes sur le paléoenvironnement, les relations Homme-climat-végétation et l'émergence de l'impact anthropique. Pour de futures recherches, il serait nécessaire d'obtenir plus de données sur la pluie pollinique d’un maximum de taxons, sur les exigences écologiques des espèces végétales et les paramètres climatiques actuels propre à chaque île, afin de modéliser de façon robuste les paysages, les climats et l’influence de l’Homme sur la dynamique de végétation passée (projet LandCover6k) / The first settlers reached the Remote Oceania (east of the Solomon Islands) quite recently, around 3000 yr BP. There are several hypotheses concerning the causes of these migrations, and environmental changes have to be taken into account in the settlement proceeding. The arrival of populations on pristine islands has an influence on the native fauna and flora, but landscape responses to human impact vary for each site examined. The aims of this research are to describe the human influence on the environment since the first migrations, to discriminate the climate impact, which causes theses migrations and the landscape modification during the late Holocene; then, to characterize the human behaviour and adaptation on pristine island. To answer this problem, two palustrine cores, collected in Efate Island (central Vanuatu) were studied: the Emaotfer Swamp and the Otas Lake.I have mainly used pollen and micro-charcoal analyses to reconstruct the arboreal and herbaceous vegetation found around the sites. I have also conducted of past temperatures and rainfalls reconstructions thanks to density probability functions. At the climatic level, these analyses highlight a warm and wet period until 3700 cal yr BP. Then, a increase in magnitude and number of El Niño events caused a drier environment. Between 1950 and 750-600 cal yr BP, the results reveal a more humid climate, associated with the decrease in El Niño frequency and magnitude. The climatic variations recorded by the Otas Lake and the Emaotfer Swamp vegetation show a new dry period after 750-600 cal yr BP, corresponding to the Little Ice Age.Lapita people reached Efate Island ca. 3000 cal yr BP under frequent and sustained El Niño events. During this period, easterly winds stopped and favoured eastward sail. These results support the hypothesis of eastward migrations under low trade winds. The first settlers were seafarers and fishers-gatherers, they had little impact on the environment. A new population settled the Emaotfer Swamp from 1500-1300 cal yr BP, developed medicinal, ceremonial and food plants cultivations and has probably practiced slash and burn agriculture. This group lived under humid climate, also more suitable to the development of horticulture. Our results show the adaptive capacity of populations to new environmental and climatic constraints. The complementary of the pollen and micro-charcoal analyses deliver rather complete information on the palaeoenvironment, the Human-climate-vegetation relations and the emergence of the human impact. For future researches, it will be necessary to obtain more information on the pollen rain for a maximum of taxa, the ecological needs of plant species and the specific climate parameters for each island, to develop a robust model of past landscapes, climates and land-use (project LandCover6k).

L’archipel volcanique actif du Vanuatu s’édifie au coeur du pacifique sud-ouest au niveau de la frontière convergente des plaques australienne et pacifique. Je présente ici une nouvelle étude géochimique des laves du Vanuatu à partir de la détermination des compositions en éléments majeurs et traces, et des compositions isotopiques (Sr-Nd-Hf-Pb) d’une centaine d’échantillons de laves (< 2 Ma).L’étude des magmas les plus primitifs a permis de mettre en évidence la variation de composition des sources mantelliques le long de l’arc et d’individualiser 3 segments : "central", dans la zone de collision de la ride D’Entrecasteaux, "sud" en face du bassin Nord Fidjien, et "extrême sud" en face du bassin Sud Fidjien. La composition des roches des différentes structures subductées influence celles des laves des volcans adjacents via le composant de subduction, sous forme de fluides et de produits de fusion. Les laves des îles situées en face de la ride D’Entrecasteaux sont issues d’un manteau enrichi ("type-MORB indien"), différent de celui échantillonné par les autres laves ("type-MORB pacifique"). Cette ride apporte probablement en subduction un composant ancien, pouvant être assimilé à un fragment de croûte inférieure.L’étude locale de certaines îles a permis de caractériser la différenciation des laves par cristallisation fractionnée, d’identifier des processus d’assimilation crustale, et de révéler la présence de magma provenant de portions de manteau distinctes, ayant subi un métasomatisme différent.Ces travaux révèlent une extrême hétérogénéité du manteau sous l’arc du Vanuatu, témoignant de la complexité des processus géologiques impliqués au niveau de cette zone de subduction. / The Vanuatu island arc is located in the SW Pacific at the convergent boundary between the Australian and Pacific plates. I present here a new geochemical study of the Vanuatu lavas based on major and trace element as well as isotopic (Sr-Nd-Hf-Pb) analyses of approximately one hundred lava samples (< 2 My).Examination of the most primitive magmas reveals the variation of the mantle source composition along the arc and demarcates three segments: a "central" segment in front the d’Entrecasteaux ridge, a "south" segment in front of the North Fiji Basin, and a "far south" segment in front of the South Fiji Basin. The composition of the different subducted basins highly influenced those of the adjacent volcanoes via mass transfer of aqueous fluid and melt subduction components. Lavas from islands facing the D'Entrecasteaux Ridge come from an enriched mantle (Indian MORB-like), distinct from that sampled at other islands (Pacific MORB-like). Additionally, this ridge likely carries with it an ancient component that may reflect entrainment of lower crust material.Localized study of some volcanic islands reveals processes related to the differentiation of lavas by fractional crystallization, processes related to crustal assimilation, and indicates the presence of magma coming from different portions of mantle with slightly different metasomatic histories.This body of work highlights extreme mantle heterogeneity under Vanuatu islands arc and testifies to the complex nature of its associated geological processes.

This is a study of coming to know what it is to be Paamese. The work seeks to present an anthropological understanding of ontological concerns that constitute a Paamese perception of subjectivities. I take my lead from Paamese perceptions that the internal capacities of subjects or “things” (e.g. persons, villages, islands, and movement itself) are revealed through relations with others. This correlates with anthropology’s methodology of testing its analytical strategies through the ethnographic practices of others in order to reach more accurate representations. Paamese, as is common elsewhere in Vanuatu and Melanesia, have an extremely fluid attitude towards sociality and easily accommodate urban dwelling without leaving Paama behind. I suggest that a nuanced multi-positioned approach in which several aspects of Paamese sociality are considered from a point of limitation employed by Paamese to focus an event, such as a marriage exchange, will present a better understanding of how these subjectivities, that is Paamese people and Paama Island, adhere such that they do not part company wherever they go. Paamese suggest that each event should be considered as if following a single branch in the canopy of a tree – a scalable perception that offers the promise that a multi-faceted approach will reveal a replicable form. I take this approach to specificity seriously and employ a looping aesthetic, measi, adapted from Paamese sand-drawing in order to consider the shifting concerns expressed by Paamese perceptions of out (place), āmal (agnatic clans), sise (road), vatte (origin), ara (blood) and asi (bone). I suggest that these, parts, can be considered together as a holography for how to come to know what it is to be Paamese.

This thesis has two main objectives. First, it outlines a taxonomy of reflexive development practice, which aims at transcending the divide between modernism and postmodernism in the methodology of development economics. Second, the thesis examines the taxonomy in two countries at opposite ends of the development spectrum, Vanuatu and Singapore, attempting to show that the taxonomy provides insights for policymaking. The taxonomy is the principal contribution. It suggests an examination of external values and norms; an assessment of the importance of local context; a recognition that policies can worsen the problems that they try to solve; and the idea that theory and policy should be revised as circumstances change. The taxonomy is developed as a way of addressing the difficulties encountered by the modernist Washington Consensus on the one hand and postmodernism on the other. Some postmodernists have criticised modernists for trying to make universal statements based on findings specific to a particular time and context. A further criticism is that the modernist-type theorising exemplified by the Washington Consensus assumes too much certainty, putting excessive faith in the ‘expert’ outsider. Postmodernists, on the other hand, have often been criticised for being relativist or even being against theory itself. In extreme versions of postmodernism, the entire rejection of epistemological foundations allows no analysis or significant discussion. The taxonomy aims to steer away from the pitfalls of either tradition, emphasising in particular the unity of theory and practice and the need for analysis and policy advice to take account of both the objectivism of the outsider and the subjectivism of the insider. The thesis is divided into two parts. The first part discusses how the open systems approach of critical realism, John Maynard Keynes and the neo-Austrians aims to overcome the difficulties of modernism and postmodernism. It then examines some of the principal uses of the term reflexivity in the past century or so, suggesting that some of these uses are compatible with each other and with the idea of open systems. This section draws on the work of several economic methodologists and sociologists, including Karl Marx, Karl Mannheim, Pierre Bourdieu, Anthony Giddens and thinkers within the sociology of scientific knowledge. Next is a critical discussion of the Washington Consensus and its amended version, followed by the development of the taxonomy. Part two begins with a brief discussion of the nature of comparison within developing economies, before looking at the taxonomy in the context of Vanuatu and Singapore. Following the case-studies is an attempt to draw lessons from the experience of the two countries. Finally, the discussion is summarised and some conclusions established.

Monthly δ18O and Sr/Ca records generated from modern and fossil corals from Southwestern Pacific Ocean sites in the Republic of Vanuatu are used to assess the differences in mean climate state, seasonality, and interannual variability between a glacial and interglacial period. The modern coral contains a well-defined annual signal in δ18O and Sr/Ca. The top 40 cm of the coral used in this study has a mean δ18O value of -4.99+/-0.13%VPDB (2σ) and a mean Sr/Ca value of 8.691+/-0.015mmol/mol (2σ). El Nino-Southern Oscillation (ENSO) events are characterized by positive δ18O and Sr/Ca anomalies, consistent with cooler temperatures and reduced rainfall that typifies ENSO at Vanuatu. The ~12cm long fossil coral is dated to 346 ka + 25, - 9, based on uranium-series analysis and stratigraphic forward modeling, indicating that the fossil coral grew during MIS10 - a glacial period. X-ray diffraction, petrographic inspection, SEM analysis, and geochemical considerations indicate excellent preservation. The mean δ18O value is enriched by 0.74%, and the mean Sr/Ca value is equivalent, compared to the modern coral. Mathematical modeling of Pleistocene mean SST and SSS results in temperature estimates up to ~2˚C warmer and salinity up to ~2 psu saltier than present-day conditions, if seawater Sr/Ca were 1-2% higher in MIS10. Our fossil coral data and modeling results preclude colder SST and lower SSS at Vanuatu during MIS10. Accurate estimates of past values of seawater Sr/Ca remain the largest obstacle to accurately reconstructing past tropical SST using pristine fossil corals. The fossil coral Sr/Ca annual range is similar to the modern range, indicating that seasonal SST ranges were similar, whereas the δ18O annual range is about half that of the modern coral, indicating weaker past seasonal salinity variations. The reduced seasonal SSS variations and increased SSTs near Vanuatu are interpreted as evidence that the SPCZ was displaced from its present location while the fossil coral lived. The geochemical response to El Niño events in the modern coral is observed twice in the fossil coral record, indicating that ENSO-like processes are not unique to interglacial time periods, but characterize the tropical Pacific at least back to MIS 10.

The Choice Modelling technique is an emerging technique which appears to have strengths relative to other non-market valuation techniques. The latter group are important in the assessment of the tradeoffs involved in environmental and resource use tradeoffs. However, the use of these techniques is often criticised where ethical and moral frameworks are involved, where it is unclear how difficult choices are being framed against each other, or where it is unclear how values change according to the scope of the amenity under consideration The primary focus of the thesis is on the development of the Choice Modelling technique, which provides a richer information set to researchers than other techniques such as Contingent valuation method. However, the richness of this data is offset to some degree by the complexity of application, where careful attention is needed for design, application and analytical stages. In this thesis, a series of four Choice Modelling experiments are reported, as well as two small Contingent Valuation experiments. The Choice Modelling experiments were centred on the estimation of values that Australians might hold for rainforest conservation in Vanuatu. In order to frame and scope the tradeoffs of interest within the broad pool of substitute goods (such as rainforest conservation opportunities in other countries), the Choice Modelling technique appeared more suitable than the single tradeoff preservation of the Contingent Valuation method. The results of Choice Modelling experiments involved sets of parameters indicating that the probability of choice depended on a number of attributes used to make up the conservation profiles together with the influence of unobserved attributes. As a willingness-to-pay variable was included within the attributes making up choice profiles, estimates of value were available by predicting how changes in particular attributes could be offset by changes in the willingness-to-pay variable. The major conclusions of the research presented in the thesis were that the involvement with ethical and moral frameworks does not invalidate the use of non-market valuation techniques, and that the Choice Modelling technique has strengths in relation to scooping and framing issues. In particular, the research demonstrates that the information generated from an experiment can be used in an iterative approach to develop more accurate models of choice. As well, the research shows that the amenity of interest, rainforest conservation in Vanuatu, can have positive values for Australian residents relative to other conservation opportunities.

This thesis endeavours to explore, describe and portray the author's attempt to work with the people of Vanuatu, a small island nation in the South Pacific, establishing a preventative eye care project. The goal of this study is to offer a contribution to the understanding of cross-cultural health work in Vanuatu. / thesis (PhD)--University of South Australia, [2000]

Le Vanuatu, archipel situé dans le Pacifique Sud, a longtemps été épargné par la vague de la mondialisation culturelle. Mais, depuis quelques années, les brassages culturels s'intensifient, menaçant une culture traditionnelle et ancestrale. L'entrée du Vanuatu dans le nouveau village planétaire mérite donc que l'on s'y intéresse de plus près. L'arrivée des nouvelles technologies de l'information et de la communication, le tourisme de masse, le passage d'une économie traditionnelle à une économie moderne, le Vanuatu doit aujourd'hui repenser sa culture pour s'insérer dans la modernité sans s'aliéner. Car, au rythme actuel du brassage culturel, on est porté à croire qu'à terme, la culture traditionnelle risquera de disparaître du fait de sa marginalisation, de son abandon par le peuple lui-même au profit de la culture occidentale et du modernisme. La culture traditionnelle est très importante et toujours très vivante dans la vie des Mélanésiens. Ce n'est pas seulement un certain nombre de rituels, de cérémonies et de traditions, c'est aussi un mode de vie qui dicte le comportement et donne des interprétations sur ce qui se produit. La coutume et les traditions ancestrales existent depuis des siècles et permettent le respect dans la communauté. Trouvant sa place entre anthropologie et communication, cette recherche porte sur la façon dont la mondialisation s'insère dans les pratiques traditionnelles au Vanuatu, plus précisément dans les danses coutumières, gui rythment la vie locale. Puisque le rapprochement entre les cultures peut conduire à une nouvelle richesse culturelle, mais puisqu'il peut aussi faire disparaître certains us et coutumes, nous sommes allés sur le terrain pour observer, sentir et comprendre ce qui s'y passe réellement. À travers les concepts de culture, d'acculturation, de syncrétisme culturel, et d'identité culturelle, nous allons découvrir un Vanuatu moderne, gui découvre l'impératif unitaire, un Vanuatu traditionnel tout en étant teinté d'occidentalisation. Les transformations majeures induites par la mondialisation culturelle, à travers les produits culturels, les différentes Églises et les migrations vers la ville remodèlent profondément les sociétés locales, et obligent les ni-Vanuatu à combiner plusieurs formes d'identification produites par des expériences sociales diverses. Toutes les sphères d'activités, qu'elles soient techniques, esthétiques, historiques ou autres, sont affectées par le phénomène. Pourtant, toute inclusion appelle une représentation préalable, un exercice de création de l'esprit nécessaire pour que tout élément extérieur soit en adéquation avec les valeurs et les aspirations propres à la société mélanésienne. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : mondialisation culturelle, culture, folklorisation, modernité, tradition, acculturation, enculturation, syncrétisme culturel, identité culturelle

Thesis (M.Sc.)--Victoria University of Wellington, [2008] / Includes bibliographical references.

The El Niño-Southern Oscillation (ENSO) dominates global interannual climate variability. However, the imprint of anthropogenic climate change hinders understanding of natural ENSO variability. Model predictions of the response of future ENSO variability to anthropogenic forcing are highly uncertain. A better understanding of how ENSO operates during different mean climate states may improve predictions of its future behavior. This study develops a technique to quantify the response of tropical Pacific sea surface temperature and salinity to ENSO variations. This analysis defines expected regional relationships between ENSO forcing and the tropical Pacific climate response. For example, the western tropical Pacific records El Niño events with greater skill than La Niña events; whereas the oceans near the South Pacific Convergence Zone (SPCZ) preferentially record La Niña events. This baseline understanding of regional skill calibrates interpretations of both modern and pre-instrumental coral geochemical climate proxy records. A suite of monthly resolved 18O variations in a fossil corals (Porites spp.) from the tropical western Pacific (Papua New Guinea) and the SPCZ (Vanuatu) are used to develop case studies of ENSO variability under external forcing conditions that differ from the modern climate. A record from Misima, Papua New Guinea (1411-1644 CE) spans a period of reduced solar forcing that coincides with the initiation of the Little Ice Age. This record indicates that the surface ocean in this region experienced a small change in hydrologic balance with no change in temperature, extended periods of quiescence in El Niño activity, reduced mean El Niño event amplitudes, and fewer large amplitude El Niño events relative to signals captured in regional modern records. Several multidecadal (~30-50 year) coral records from Tasmaloum, Vanuatu during the Medieval Climate Anomaly (~900-1300 CE), a period of increased solar forcing, depict ENSO variability that is generally lower than modern times. However, these records often cannot be distinguished from 20th century ENSO variability due to ENSO variability uncertainty associated with record lengths. Neither record can be tied to concurrent changes in solar or volcanic forcing, calling into question the paradigm of ENSO variability being predominantly mediated by external forcing changes on multidecadal time scales. / text