Vulnerability and resilience of remote rural communities to shocks and global changes: Empirical analysis from Solomon Islands

Successful management of socio-ecological systems not only requires the development and field-testing of robust and measurable indices of vulnerability and resilience but also improved understanding of the contextual factors that influence societal capacity to adapt to change. We present the results of an analysis conducted in three coastal communities in Solomon Islands. An integrated assessment map was used to systematically scan the communities’ multiple dimensions of vulnerability and to identify factors affecting households’ perception about their capacity to cope with shocks (resilience). A multivariate probit approach was used to explore relationships amongst factors. Social processes such as community cohesion, good leadership, and individual support to collective action were critical factors influencing the perception that people had about their community's ability to build resilience and cope with change. The analysis also suggests a growing concern for a combination of local (internal) and more global (external) contingencies and shocks, such as the erosion of social values and fear of climate change.     

Evaluation of the controls affecting the quality of spatial data derived from historical aerial photographs

This paper is concerned with the fundamental controls affecting the quality of data derived from historical aerial photographs typically used in geomorphological studies. A short review is provided of error sources introduced into the photogrammetric workflow. Data‐sets from two case‐studies provided a variety of source data and hence a good opportunity to evaluate the influence of the quality of archival material on the accuracy of coordinated points. Based on the statistical weights assigned to the measurements, precision of the data was estimated a priori, while residuals of independent checkpoints provided an a posteriori measure of data accuracy. Systematic discrepancies between the two values indicated that the routinely used stochastic model was incorrect and overoptimistic. Optimized weighting factors appeared significantly larger than previously used (and accepted) values. A test of repeat measurements explained the large uncertainties associated with the use of natural objects for ground control. This showed that the random errors not only appeared to be much larger than values accepted for appropriately controlled and targeted photogrammetric networks, but also small undetected gross errors were induced through the ‘misidentification’ of points. It is suggested that the effects of such ‘misidentifications’ should be reflected in the stochastic model through selection of more realistic weighting factors of both image and ground measurements. Using the optimized weighting factors, the accuracy of derived data can now be more truly estimated, allowing the suitability of the imagery to be judged before purchase and processing. Copyright © 2010 John Wiley & Sons, Ltd.     

The Geological Conservation Review (GCR) in Great Britain—Rationale and methods

Geoconservation – protecting, managing and enhancing natural geological features and materials, and geomorphological landforms and processes – is especially important in Great Britain, a place sometimes described as the ‘cradle’ of the science of geology. For such a small area of land, Britain has an unusually diverse geological make-up, with rocks from every geological period present. Many stratigraphical terms used internationally were devised here, and British sites provide key study areas where important new geological theories were developed in the pioneering era of the Earth sciences. Therefore, with such a wealth of geology, and Britain's seminal place in the science itself, it is particularly important to conserve and protect key localities here for future generations. A first step in that process is the auditing of the geology and geomorphology of Britain, by carrying out a scientific evaluation exercise according to standard criteria, and creating an inventory of the most important sites for science.In the mid-1970s, the Nature Conservancy Council (NCC) began an ambitious programme for assessment and documentation of the most important sites for the scientific study of geology and geomorphology in Great Britain, building on previous statutory site conservation activity that had already been started in 1949 by the former Nature Conservancy. As a result, the ‘Geological Conservation Review’ (GCR) was formally launched in 1977. The GCR was a world-first project of its type in the systematic assessment of the whole geological heritage of a country, from first principles. Widespread consultation with geologists and geomorphologists across Great Britain was co-ordinated; their guidance and involvement was a key component of the site selection process. Almost 3000 nationally or internationally important sites had been selected for around 100 site-selection categories for the GCR register by 1990. Almost all the GCR sites are now conserved under British law as Sites of Special Scientific Interest (SSSIs), the GCR information providing the scientific evidence-base that underpins that designation.As part of the site-selection process – which is still active – a considerable archive of information about geological sites was amassed. A major publication exercise detailing all the GCR sites in what was to become the GCR Series of books was devised early on in the GCR programme.Thirty-six volumes of the GCR Series have been seen to completion by NCC and the Joint Nature Conservation Committee, and many GCR site reports have been many made freely available on the World Wide Web. As a new venture, the remaining nine volumes will now be published by Elsevier Science Publishers as Special Issues of the Proceedings of the Geologists’ Association. Each GCR volume includes an overview of the subject and outlines the history of study of the relevant branch of the Earth sciences, but most importantly contains detailed accounts of the features of geological importance in the sites described. A scientific interpretation is provided for each site account, which includes supportive illustrations, tables and photographs and an extensive reference list.The GCR rationale, methods and information resource have been invaluable in almost every aspect of geoconservation carried out in Britain, including World Heritage Site nominations, protection of stratotypes, justifying the scientific conservation value of sites at Public Inquiries, in stimulating geological research and in providing a readily available information resource for local, regional, national and international geoconservation activities.     

Reconstructing flow paths of the Middle Pleistocene British Ice Sheet in central-eastern England: the application of regional soil geochemical data

High-density regional geochemical data for surface soils in central England and East Anglia reveal that much of their geochemical character is inherited from the tills that they are developed upon. Multivariate statistical analysis highlighted three significant element associations of Al–Fe–Ga–K–La–Mg–Rb, Ca–Sr and K–Fe accounting for almost 93% of the geochemical variability of soils derived from tills. Provenancing the geochemical signatures of the latter elements enabled the construction of ice flow paths associated with two different Middle Pleistocene ‘chalky’ till sheets. A lower till sheet relating to ‘Pennine’ ice flowing from west to east across the region, and an upper till sheet deposited by North Sea ice moving into northern East Anglia, and to the west of the Fen Basin, before fanning-out across central England. Overall, geochemical signatures of different till units are largely derived from local bedrock sources, with dilution and a new geochemical signature acquired as the ice flows over and incorporates new bedrock lithologies. The results show that high resolution soil geochemical data provides a further proxy with which the flow paths of former ice sheets can be delineated.     

Cosmogenic nuclide exposure ages for moraines in the Lago San Martin Valley, Argentina

At several times during the Quaternary, a major eastward-flowing outlet glacier of the former Patagonian Ice Sheet occupied the Lago San Martin Valley in Argentina (49°S, 72°W). We present a glacial chronology for the valley based on geomorphological mapping and cosmogenic nuclide (¹⁰Be) exposure ages (n = 10) of boulders on moraines and lake shorelines. There are five prominent moraine belts in the Lago San Martin Valley, associated with extensive sandar (glaciofluvial outwash plains) and former lake shorelines. Cosmogenic nuclide exposure ages for boulders on these moraines indicate that they formed at 14.3 ± 1.7 ka, 22.4 ± 2.3 ka, 34.4 ± 3.4 ka to 37.6 ± 3.4 ka (and possibly 60 ± 3.5 ka), and 99 ± 11 ka (1σ). These dated glacier advances differ from published chronologies from the Lago San Martin Valley based on ¹⁴C age determinations from organic sediments and molluscs in meltwater channels directly in front of moraines or in kettleholes within end moraine ridges. The moraine boulder ages also point to possible pre-LGM glacial advances during the last glacial cycle and a key observation from our data is that the LGM glaciers were probably less extensive in the Lago San Martin Valley than previously thought.     

Quantitative evaluation of crosshole seismic reflection images using physical model data1

Physical models give us a known geometry with which to compare our processed reflection images and therefore our imaging techniques. We show how this comparison may be quantified in order to evaluate processed images properly. A crosshole data set was acquired through a model interrogated at ultrasonic frequencies using Durham University's physical modelling system. Various reflectivity images were obtained using processing sequences which include deconvolution, wavefield separation and migration. An error-energy scheme was used to assess the quality of these images, by comparing them against a best-fit depth model. A synthetic data set was also used to evaluate the imaging capability of the crosshole geometry and the effectiveness of the different processing schemes.     

Surface measurements of carbon dioxide and methane at Alert during an Arctic haze event in April, 1986

Carbon dioxide (CO₂) has been measured at Alert by grab flask sampling since 1975 as part of the World Meteorological Organization's Background Air Pollution Monitoring Program. Deviations of CO₂ concentration from the mean annual cycle have previously been attributed to air masses arriving at Alert from the source regions of the industrialized parts of Europe and the Soviet Union. In situ measurements of ambient CO₂ and methane (CH₄) were made at Alert using an automated gas chromatograph, as part of the Arctic Haze Study during April 1986. The temporal behaviour of CO₂ and CH₄ during this period was found to be highly correlated with measurements of particulate sulphate and other atmospheric trace species of anthropogenic origin. Examination of calculated air mass back-trajectories provided further evidence that the observed short-term increases in CO₂ and CH₄ mixing ratios were due to long-range transport from anthropogenic source regions.     

Geometry,bed topography and drainage system structure of the haut glacier d'Arolla,Switzerland

As part of an integrated study of the hydrology, meltwater quality and dynamics of the Haut Glacier d'Arolla, Switzerland, the glacier's drainage network structure was determined from patterns of dye recovery in 342 injection experiments conducted from 47 moulins distributed widely across the glacier. This structure was compared with theoretical predictions based upon reconstructed patterns of water flow governed by (a) the subglacial hydraulic potential surface, and (b) the subglacial bedrock surface. These reconstructions were based on measurements of ice surface and bedrock topography obtained by a combination of ground survey and radio-echo sounding techniques. The two reconstructions simulate the drainage system structures expected for (a) closed channels, in which water is pressurized by the overlying ice, and (b) gravity-driven, open-channel flow. The closed-channel model provides the best fit to the observed structure, even though theoretical calculations suggest that, under summer discharge conditions, open-channel flow may be widespread beneath the glacier. Possible reasons for this apparent discrepancy are discussed.     

Dynamical geochemistry of the Hawaiian plume

This paper presents a simple dynamical model for melting and trace element distribution in the Hawaiian mantle plume. I model the plume as a partially molten stagnation point flow against the oceanic lithosphere, and obtain solutions for the temperature, melt migration rate, and trace element concentration within it. Trace element concentrations in the melt exceed simple batch melting predictions by up to 70%. The magnitude of this effect depends strongly on the solid-melt partition coefficientK. Trace elements with differentK therefore experience a “dynamical fractionation” within the plume, and incompatible trace element ratios such asLa/Ce always exceed the batch melting predictions. I suggest a simple model for plume-lithosphere interaction in which melts from these two sources mix in proportions determined by thermodynamic constraints. The model can explain the composition of basalts from Haleakala if the degree of melting of the lithosphereF₁ decreases with time from roughly 10% for tholeiites to 2% for alkalic basalts. These values are considerably higher than previous estimates ofF₁ < 1%, and imply correspondingly smaller and more realistic values ( 10 km) for the thickness of the melted part of the lithosphere. Partial melting of additional depleted sources such as the asthenosphere is therefore not required by the Haleakala data. Estimates ofF₁ are highly sensitive to the values chosen for the partition coefficients, however, and should therefore be interpreted with caution.