A survey of the inorganic chemistry of bottled mineral waters from the British Isles

The inorganic chemistry of 85 samples of bottled natural mineral waters and spring waters has been investigated from 67 sources across the British Isles (England, Wales, Scotland, Northern Ireland, Republic of Ireland). Sources include boreholes, springs and wells. Waters are from a diverse range of aquifer lithologies and are disproportionately derived from comparatively minor aquifers, the most represented being Lower Palaeozoic (10 sources), Devonian Sandstone (10 sources) and Carboniferous Limestone (9 sources). The waters show correspondingly variable major-ion compositions, ranging from Ca–HCO₃, through mixed-cation–mixed-anion to Na–HCO₃ types. Concentrations of total dissolved solids are mostly low to very low (range 58–800 mg/L). All samples analysed in the study had concentrations of inorganic constituents well within the limits for compliance with European and national standards for bottled waters. Concentrations of NO₃–N reached up to half the limit of 11.3 mg/L, although 62% of samples had concentrations <1 mg/L. Concentrations of Ba were high (up to 1010 μg/L) in two spring water samples. Such concentrations would have been non-compliant had they been classed as natural mineral waters, although no limit exists for Ba in European bottled spring water. In addition, though no European limit exists for U in bottled water, should a limit commensurate with the current WHO provisional guideline value for U in drinking water (15 μg/L) be introduced in the future, a small number of groundwater sources would have concentrations close to this value. Two sources had groundwater U concentrations > 10 μg/L, both being from the Welsh Devonian Sandstone. The highest observed U concentration was 13.6 μg/L.     

Lunar and solar daily variations of the geomagnetic field at Toolangi

Summary Mean hourly values of magnetic declination, horizontal intensity and vertical intensity observed at Toolangi during two ten year periods (1924–1933 and 1949–1958) have been analysed to determine their solar and luni-solar diurnal components. The results, showing the variations of the first four harmonic components with season, degree of magnetic activity and annual sunspot number, are tabulated and discussed. It is shown that there are marked differences in the dependence ofS andL on the various parameters and a tentative explanation of this phenomenon is given.     

Semi-Supervised Multi-Facies Object Retrieval in Seismic Data

Mathematical Geosciences - Characterizing buried sedimentary structures through the use of seismic data is part of many geoscientific projects. The evolution of seismic acquisition and processing...     

Facilitating adaptation of biodiversity to climate change: a conceptual framework applied to the world’s largest Mediterranean-climate woodland

The importance of ecological management for reducing the vulnerability of biodiversity to climate change is increasingly recognized, yet frameworks to facilitate a structured approach to climate adaptation management are lacking. We developed a conceptual framework that can guide identification of climate change impacts and adaptive management options in a given region or biome. The framework focuses on potential points of early climate change impact, and organizes these along two main axes. First, it recognizes that climate change can act at a range of ecological scales. Secondly, it emphasizes that outcomes are dependent on two potentially interacting and countervailing forces: (1) changes to environmental parameters and ecological processes brought about by climate change, and (2) responses of component systems as determined by attributes of resistance and resilience. Through this structure, the framework draws together a broad range of ecological concepts, with a novel emphasis on attributes of resistance and resilience that can temper the response of species, ecosystems and landscapes to climate change. We applied the framework to the world’s largest remaining Mediterranean-climate woodland, the ‘Great Western Woodlands’ of south-western Australia. In this relatively intact region, maintaining inherent resistance and resilience by preventing anthropogenic degradation is of highest priority and lowest risk. Limited, higher risk options such as fire management, protection of refugia and translocation of adaptive genes may be justifiable under more extreme change, hence our capacity to predict the extent of change strongly impinges on such management decisions. These conclusions may contrast with similar analyses in degraded landscapes, where natural integrity is already compromised, and existing investment in restoration may facilitate experimentation with higher risk?options.     

Changes in carbon and nutrient fluxes from headwaters to ocean in a mountainous temperate to subtropical basin

Water erosion provides major links in global cycles of carbon (C), nitrogen (N) and phosphorus (P). Although significant research on erosion mechanisms has been done, there is still little knowledge on C, N and P fluxes across landscapes to the ocean and their controlling factors in subtropical climates. A four‐year study quantifying and comparing particulate and dissolved C, N and P from multiple scales (microplot, plot, microcatchment, subcatchment, catchment, sub‐basin and basin) was performed in Thukela basin (≈30 000 km²), South Africa. The basin climate was largely subtropical‐humid [mean annual precipitation (MAP) > 980 mm yr^‐1], but temperate (MAP >2000 mm yr^‐1) on the highlands. Open grassland, cropland and bushland were the major land uses. On average, 65, 24 and 4 g m^‐2 yr^‐1 C, N and P were displaced from original topsoil positions, but only 0.33, 0.005 and 0.002 mg m^‐2 yr^‐1 were, respectively, exported to the ocean. The fluxes decreased by 95, 97 and 84%, respectively, from plot to microcatchment outlet; and decreased further in downstream direction by >99% from microcatchment to basin outlet. The hillslope (microplot to microcatchment) fluxes correlated strongly with rainfall parameters. Particulate contributions dominated hillslope fluxes at 73, 81 and 76% of total annual C, N and P, respectively. Although particulate C dominated in the microcatchment‐catchment reach (55%), N (54%) and P (69%) were dominated by dissolved forms. The lower basin zone was dominated by dissolved flux contributions at 93, 81 and 78% for C, N and P for the sub‐basin outlet. These results suggested spatially varying drivers of C, N and P losses from the landscape to the ocean, via the river network. Deposition was envisaged the dominant hillslope level loss process, which gradually gave way to mineralization and biotic uptake in the river network as flux contributions shifted from being predominantly particulate to dissolved forms. Copyright © 2017 John Wiley & Sons, Ltd.     

Selective organic carbon losses from soils by sheet erosion and main controls

Although the impact of sheet erosion on the selective transportation of mineral soil particles has been widely investigated, little is yet known about the specific mechanisms of organic carbon (OC) erosion, which constitutes an important link in the global carbon cycle. The present study was conducted to quantify the impact of sheet erosion on OC losses from soils. Erosion plots with the lengths of 1‐ and 5‐m were installed at different topographic positions along a hillslope in a mountainous South African region. A total of 32 rainfall events from a three years period (November 2010 up to February 2013), were studied and evaluated for runoff (R), particulate and dissolved organic carbon (POC_L and DOC_L). In comparison to the 0–0·05 m bulk soil, the sediments from the 1‐m plots were enriched in OC by a factor 2·6 and those from the 5‐m long plots by a factor of 2·2, respectively. These findings suggest a preferential erosion of OC. In addition, total organic carbon losses (TOC_L) were incurred mainly in particulate form (~94%) and the increase in TOC_L from 14·09 ± 0·68 g C m^?1 yr^?1 on 1‐m plots to 50·03 ± 2·89 g C m^?1 yr^?1 on 5‐m plots illustrated an increase in sheet erosion efficiency with increasing slope length. Both TOC_L and sediment enrichment in OC correspondingly increased with a decrease in soil basal grass cover. The characteristics of rainstorms had no significant impact on the selectivity of OC erosion. The results accrued in this study investigating the links between sheet erosion and OC losses, are expected to be of future value in the generation of carbon specific erosion models, which can further help to inform and improve climate change mitigation measures. Copyright © 2016 John Wiley & Sons, Ltd.     

Erratum: Properties of a pair of fracture networks produced by triaxial deformation experiments: insights on fluid flow using discrete fracture network models

Results of a series of deformation experiments conducted on gabbro samples and numerical models for computation of flow are presented. Rocks were subjected to triaxial tests (σ1 > σ2 = σ3) under σ3 = 150 MPa confining pressure at room temperature, to generate fracture network patterns. These patterns were either produced by keeping a constant confining pressure and loading the sample up to failure (conventional test: CT), or by building up a high differential stress and suddenly releasing the confining pressure (confining pressure release test: CPR). The networks are similar in overall density but differ primarily in the orientation of smaller fractures. In the case of CT tests, a conjugate fracture set is observed with one dominant fracture zone running at about 20° from σ1. CPR tests do not show such a conjugate pattern and the mean fracture orientation is at around 35° from σ1. Discrete fracture network (DFN) methodology was used to determine the distribution of flow and hydraulic head for both fracture sets under simple boundary conditions and uniform transmissivity values. The fracture network generated by CT and CPR tests exhibit different patterns of flow field and hydraulic head configurations, but convey approximately the same amount of flow at all scales for which DFN models were simulated. The numerical modelling results help to develop understanding of qualitative differences in flow distribution that may arise in rocks of the same mineralogical composition and mechanical properties, but under the influence of different stress conditions, albeit at similar overall stress magnitude.

     

Multi-decadal scale variability in autumn-winter rainfall in south-western Australia since 1655 AD as reconstructed from tree rings of Callitris columellaris

We present the first tree-ring based reconstruction of rainfall for the Lake Tay region of southern Western Australia. We examined the response of Callitris columellaris to rainfall, the southern oscillation index (SOI), the southern annular mode (SAM) and surface sea temperature (SST) anomalies in the southern Indian Ocean. The 350-year chronology was most strongly correlated with rainfall averaged over the autumn-winter period (March–September; r = ?0.70, P < 0.05) and SOI values averaged over June–August (r = 0.25, P < 0.05). The chronology was not correlated with SAM or SSTs. We reconstructed autumn-winter rainfall back to 1655, where current and previous year tree-ring indices explained 54% of variation in rainfall over the 1902–2005 calibration period. Some variability in rainfall was lost during the reconstruction: variability of actual rainfall (expressed as normalized values) over the calibration period was 0.78, while variability of the normalized reconstructed values over the same period was 0.44. Nevertheless, the reconstruction, combined with spectral analysis, revealed that rainfall naturally varies from relatively dry periods lasting to 20–30 years to 15-year long periods of above average rainfall. This variability in rainfall may reflect low-frequency variation in the El Niño-Southern Oscillation rather than the effect of SAM or SSTs.     

A Robust Surface Matching Technique for Integrated Monitoring of Coastal Geohazards

At the dynamic coastal fringe, numerous processes interact with local morphology. In soft-cliff environments, this can often lead to the occurrence of coastal geohazards. These can pose a major threat to property and cultural heritage, and an effective monitoring strategy is therefore essential. While contemporary monitoring techniques have been applied, these are often unsuitable in isolation. This paper presents an integrated approach, with the development of weighted surface matching software enabling reliable dataset fusion and multi-temporal change detection, even where significant surface differences exist. Evaluation of this approach is presented and discussed.