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    ABSTRACT: Ice sheet flow is strongly influenced by the nature and quantity of meltwater entering the subglacial system. Accessing and monitoring contemporary drainage systems beneath ice sheets is notoriously difficult, but it is possible to utilise the exposed beds of palaeo-ice sheets. In particular, eskers record deposition in glacial drainage channels and are widespread on the exposed beds of former ice sheets. However, unlike some other common glacial landforms (e.g. drumlins) there have been relatively few attempts to investigate and quantify their characteristics at the ice sheet scale. This paper presents data on the distribution, pattern, and morphometry of a large (>20,000) sample of eskers in Canada, formed under the Laurentide Ice Sheet, including quantification of their length, fragmentation, sinuosity, lateral spacing, number of tributaries, and downstream elevation changes. Results indicate that eskers are typically very long (hundreds of km) and often very straight (mean sinuosity approximates 1). We interpret these long esker systems to reflect time-transgressive formation in long, stable conduits under hydrostatic pressure. The longest eskers (in the Keewatin sector) are also the least fragmented, which we interpret to reflect formation at an ice margin experiencing stable and gradual retreat. In many locations, the lateral distance between neighbouring eskers is remarkably consistent and results indicate a preferred spacing of around 12 km, consistent with numerical models which predict esker spacing of 8–25 km. In other locations, typically over soft sediments, eskers are rarer and their patterns are more chaotic, reflecting fewer large R-channels and rapidly changing ice sheet dynamics. Comparison of esker patterns with an existing ice margin chronology reveals that the meltwater drainage system evolved during deglaciation: eskers became more closely spaced with fewer tributaries as deglaciation progressed, which has been interpreted to reflect increased meltwater supply from surface melt. Eskers show no preference to trend up or down slopes, indicating that ice surface was an important control on their location and that the conduits were, in places, close to ice overburden pressure.
    Full-text · Article · Nov 2014 · Quaternary Science Reviews
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    ABSTRACT: Analyses of the politics of energy production have traditionally focused on issues of resource extraction and large scale generation. Yet questions of politics are just as critical when it comes to considering the development of ‘small’ energy – variously referred to as micro-or distributed generation and frequently associated with the growing role of communities in the production of renewable energy. In this paper, we focus on a resource – a local river – to examine the ways in which a community-based project sought to produce it as a viable and legitimate source of energy production. Such an initiative, we find, is fraught with challenges. In particular, we identify three facets of the production of micro-hydro power that have been critical to its deployment and contestation. First, the means through which the hydro resource is calculated and valued. Second, the ways in which recasting the river in energy resource terms serves to challenge established notions of the river. Third, the identification of hydro power as a ‘low carbon’ energy resource has at once served to create new discourses about the role and responsibilities for using the river as an energy resource, whilst also calling into question its viability in the long term under conditions of climate change.
    No preview · Article · Sep 2014 · Geoforum
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    ABSTRACT: Using the experiences of first and second generation migrants from three villages in Thailand, we “personalize” the middle income trap, seeking to understand how and why migrants with growing levels of education and human capital remain rooted to their natal villages. Agrarian change is such that the village remains the locus of familial belonging and livelihood security, limiting engagement with the knowledge economy, sometimes for good reason given the precarity of much non-farm work. We conclude that the middle-income trap for these villages in Thailand is as much personal as it is institutional and structural.
    Full-text · Article · Jul 2014 · World Development
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