Tectonic structures in the Peel Sandstones and Carboniferous limestone,Isle of Man

On the Isle of Man, the Early Devonian Peel Sandstones and Early Carboniferous limestones have been deformed in places by folds, cleavage and other structures. The structures in the Peel Sandstones have been attributed to pre‐lithification deformation associated with slumping of the red beds. Here, they are re‐interpreted to be products of post‐lithification deformation, inferred from small‐scale structures and fabrics, which took place in a localized thrust zone. Compression was approximately NW–SE and translation towards the SE. That deformation may have also produced some of the late structures in the Lower Palaeozoic rocks of the island. The minimum age of these post‐Early Devonian structures is unknown but is probably pre‐Carboniferous: they may represent the mid‐Devonian Acadian deformation. The Carboniferous succession is folded in places and contains stylolites and stylolitic cleavage. A stress regime with E–W to WNW–ESE compression is inferred. These structures have orientations and morphologies shown to resemble those in neighbouring parts of southern Britain, where they are attributed mainly to mid‐ to late‐Carboniferous Variscan events. Alternatively, some or all of them might be products of late Mesozoic and Tertiary tectonics recognized elsewhere in the region. Copyright © 2010 John Wiley & Sons, Ltd.     

Contract farming and the remaking of agrarian landscapes: Insights from South India's chilli belt

This analysis of a backward integration traceability scheme for red chillies developed by a multinational food company in India emphasizes spatial integration and differentiation within contract farming. The scheme is premised on the procurement of identically credentialed produce from 10 different sites in two states and incorporates growers in highly flexible and place‐contingent modes. Interviews with corporate informants and farmers reveal this flexibility to be the result of a two‐way process of risk management between the company and growers. The company spread its geographical exposure by initiating production across a number of far‐flung cultivation sites, and growers cultivate chillies for the company within the context of diverse agricultural systems, thereby mitigating dependence. The scheme has had positive impacts for participants, but has more complex implications for the evolution of agrarian landscapes in India. The selective enrolment of participants through ‘progressive farmer’ networks acts to reorganize rural spaces by generating new geographies of advantage and opportunity.     

The slow rotation of 253 Mathilde

CCD photometry of the NEAR mission fly-by target 253 Mathilde is presented. Measurements taken during 52 nights of observations, from February to June 1995, allow a rotation period of 17.406±0.010 days and a lightcurve amplitude of 0.45±0.02 mag to be determined. A B-V color index of 0.67±0.02 and a V-R of 0.35±0.02 are measured, which are compatible with C-type membership. The determination of the phase relation results in H = 10.28±0.03 and G = 0.12±0.06. Indications that the lightcurve is not strictly singly-periodic are found. A power-spectrum analysis detects a secondary frequency f₂ = 0.0322±0.0010 d⁻¹, which is interpreted as evidence for a complex rotation state.     

‘Rising Waters Don't Lift All Boats’: a sustainable livelihood analysis of recursive cycles of vulnerability and maladaptation to flood risk in rural Bihar,India

ABSTRACT

Bihar, in the central Gangetic Basin, is simultaneously India's poorest and most flood-prone State. Climate change models currently identify a heightening of Bihar's flood risk, as rainfall patterns become more intense and Himalayan glaciers recede. During the past half century, the major strategy deployed by the State and national governments to address the risk of floods has involved the construction of embankments: raised areas of land that seek to control river flow and provide temporary sanctuaries for flood-affected populations. In this article, qualitative data from interviews with flood-affected villagers and policy makers at local, district and State levels are used to assess the social implications of embankments as an adaptive response to flood risk. Evidence from these testimonies leads us to conceptualise embankments as contributing to recursive cycles of vulnerability, in which women, children and poorer social segments have been unwitting bearers. Hence, reliance on embankments is a maladaptation that perpetuates, if not exacerbates, the severe manifestations of social and economic inequality that continue to plague rural Bihar. Perhaps not surprisingly, the voices of those whose lives have been made more difficult by embankments are heard all too infrequently in policy debates. This emphasises the need for climate adaptation initiatives to be anchored in a sustainable livelihood approach, for which the prime analytical objective is to understand the factors that enable or constrain the abilities of people, especially those who are most vulnerable, to make decisions about their lives.     

Geographical imaginaries: Articulating the values of geography

This paper explores the concept of ‘geographical imaginaries’ in New Zealand geography. It reflects on the genealogy of the concept and on the work it might perform in the world. At a time when the purpose and contribution of geography in schools is under question and the discipline is under severe strain at universities, we ask whether the idea of ‘geographical imaginaries’ offers a conceptual platform for demonstrating the potential for geography to offer meaning in the complex world of 21st‐century New Zealand and whether it will help teachers to foster geographic thought in classrooms. In short, we argue for the merits of working with the idea of geographical imaginaries in classrooms and for utilising it to interrogate accounts of the geographical gaze and its values. This, we argue, offers opportunities to catalyse geographical thought, highlight the potential of thinking geographically, and open up a thinking space in which geography teachers can examine their pedagogy and enhance the purpose of their work. This would provide a platform for building a more imaginative and more politically and culturally relevant geography at school.     

A Note on Tree Deaths during the Current (2001–?) Drought in South-eastern Australia

Tree deaths over large areas during droughts are uncommon. In the semi-arid zone of New South Wales (NSW) such events were last reported during the prolonged droughts of 1895–1903 and 1939–45, though whether caused solely by drought is open to question. Anecdotal and quantitative evidence during the current prolonged drought (2001–?) in NSW's sub-humid zone (where deaths are localised) and semi-arid zone (where deaths are more extensive) suggest that climatic conditions are comparable to, and perhaps more severe than, those of the earlier prolonged droughts. It is suggested that lack of access to deep soil moisture due to inherent shallow rooting, or due to site conditions, is the most likely cause; and that this may be associated with higher than optimal tree densities in cohorts of trees that arose from previous regeneration events during periods of well above average rainfall. A more thorough examination of the extent and severity of this event is warranted.     

Unemployment in Non-Metropolitan Australia: integrating geography,social and individual contexts

Despite a significant period of strong economic and jobs growth nationally, there is well-established evidence in Australia that the proceeds of this growth have not been shared equally, either between places or between individuals. Empirically, it is well known that particular socioeconomic groups have a higher risk of unemployment and it has become equally well established that there are particular geographic patterns of labour market disadvantage that suggest that local geographic context is also important. What is not well understood are the ways in which phenomena at the geographic level are associated with individual-level characteristics and other social contexts in ways that negatively impact on a range of social outcomes, including unemployment. The present paper specifically addresses this issue by using a multi-scalar approach and using survey data from the Housing, Income and Labour Force Dynamics Australia (HILDA) survey and aggregate level census data to model unemployment risk. The paper argues that to better understand unemployment and to add to sound policy development, approaches that incorporate a variety of contexts, including the impact of local geographies, are important.     

Numerical study on tide-driven submarine groundwater discharge and seawater recirculation in heterogeneous aquifers

There are many factors affecting submarine groundwater discharge (SGD). However, systematic study of the influences of these factors is still limited. In this study, numerical modeling is performed to quantitatively explore the influences of various factors on SGD in a coastal aquifer. In such locations, tidal and terrestrial hydraulic gradients are the primary forces driving fresh and salt water movement. Unlike steady-state flow, dynamic fresh and salt water mixing at the near-shore seafloor may form an intertidal mixing zone (IMZ) near the surface. By constructing a general SGD model, the effects of various model components such as boundary conditions, model geometry and hydraulic parameters are systematically studied. Several important findings are obtained from the study results: (1) Previous studies have indicated there will be a freshwater discharge tube between the classic transition zone and the IMZ. However, this phenomenon may become unclear with the increase of heterogeneity and anisotropy of the medium’s conductivity field. (2) SGD and IMZ are both more sensitive to the vertical anisotropy ratio of hydraulic conductivity (K_x/K_z) than to the horizontal ratio (K_x/K_y). (3) Heterogeneity of effective porosity significantly affects SGD and IMZ. (4) Increase of the storage coefficient decreases fresh water discharge but increases mixing salt water discharge and total SGD. The increase will also change the shape of the IMZ. (5) Variation of dispersivities does not affect SGD, but significantly changes the distributions of the IMZ and the whole mixing zone. These findings will be helpful to the sampling design of field studies of SGD and to the application of dynamic SGD models to field sites for model development and calibration.