Groundwater age,mixing and flow rates in the vicinity of large open pit mines,Pilbara region,northwestern Australia     

Peter Cook  Shawan Dogramaci  James McCallum  Joanne Hedley 《Hydrogeology Journal》2017,25(1):39-53

Determining groundwater ages from environmental tracer concentrations measured on samples obtained from open bores or long-screened intervals is fraught with difficulty because the sampled water represents a variety of ages. A multi-tracer technique (Cl, ¹⁴C, ³H, CFC-11, CFC-12, CFC-113 and SF₆) was used to decipher the groundwater ages sampled from long-screened production bores in a regional aquifer around an open pit mine in the Pilbara region of northwest Australia. The changes in tracer concentrations due to continuous dewatering over 7 years (2008–2014) were examined, and the tracer methods were compared. Tracer concentrations suggest that groundwater samples are a mixture of young and old water; the former is inferred to represent localised recharge from an adjacent creek, and the latter to be diffuse recharge. An increase in ¹⁴C activity with time in wells closest to the creek suggests that dewatering of the open pit to achieve dry mining conditions has resulted in change in flow direction, so that localised recharge from the creek now forms a larger proportion of the pumped groundwater. The recharge rate prior to development, calculated from a steady-state Cl mass balance, is 6 mm/y, and is consistent with calculations based on the ¹⁴C activity. Changes in CFC-12 concentrations with time may be related to the change in water-table position relative to the depth of the well screen.  相似文献   

Short-term and seasonal variation in metabolic balance in Liverpool Bay     

Anouska Panton  Claire Mahaffey  Naomi Greenwood  Joanne Hopkins  David Montagnes  Jonathan Sharples 《Ocean Dynamics》2012,62(2):295-306

Regions of freshwater influence (ROFIs) are dynamic areas within the coastal seas that experience cycles of stability driven by density gradients and the spring-neap tidal cycle. As a result, pulses of biological production may occur on a more frequent timescale than the classic seasonal cycle. Net community production (NCP) rates and chlorophyll a concentration are presented from a site within the ROFI of Liverpool Bay and compared to similar measurements made at a site outside the ROFI during 2009. The influence of water column stability on biological production in the ROFI was also investigated using high-frequency observations from a Cefas Smartbuoy. Both sites were autotrophic from spring to autumn before becoming heterotrophic over winter. NCP at the inshore site was estimated to range from 30.8 to 50.4 gC m⁻² year⁻¹. A linear relationship detected between chlorophyll a and NCP from both sites was used to estimate metabolic balance over 1 year at the ROFI site using high-resolution chlorophyll a concentrations from the Smartbuoy but was found to poorly replicate NCP rates compared to those derived from dissolved oxygen fluxes. There was no clear biological response to periods of stratification within the ROFI, and it is proposed that changes in light attenuation in the Liverpool Bay ROFI, driven not only by stratification but also by fluctuations in riverine sediment load, most likely play an important role in controlling phytoplankton growth in this region.  相似文献   

Closed Circuit Television (CCTV) Earthquake Behaviour Coding Methodology: analysis of Christchurch Public Hospital video data from the 22 February Christchurch earthquake event     

Emily S. Lambie  Thomas M. Wilson  Erik Brogt  David M. Johnston  Michael Ardagh  Joanne Deely  Steven Jensen  Shirley Feldmann-Jensen 《Natural Hazards》2017,86(3):1175-1192

Earthquake epidemiological research indicates that the behavioural response influences the nature and severity of injuries sustained. However, there is no observational evidence of the actions individuals engage in during and immediately following earthquake shaking, and the context in which earthquake injuries and deaths are caused. Closed Circuit Television Earthquake Behaviour Coding Methodology has been developed as a tool to classify human behaviour during and immediately following earthquake shaking using real event video data. The coding methodology was applied to security video data captured during the 22 February 2011 M_w6.3 ‘Christchurch’ earthquake event from the Christchurch Public Hospital which experienced shaking intensity of MM9 lasting approximately 12–15 s. We applied this coding methodology to determine: demography, trans-event behavioural responses, post-event behavioural responses, influence of social context on behaviour, and influence of behaviour on injuries. A total of 213 individuals from 31 different camera views were analysed. Sixty-six per cent of the individuals were adult-aged females. The primary trans-event responses were to hold (26%) onto furniture, walls, and/or other people close to them and to look around (30%). No individuals were observed to perform all ‘Drop, Cover, Hold’ actions, the recommended action during strong earthquake shaking in New Zealand. Post-event behaviour included: running, walking, providing assistance, moving towards others, visual communication, and some individuals gave instructions. Social contextual behaviour varied depending on the role of the adult. There were no serious injuries linked to behaviour. The results of this initial study indicate the coding methodology can record the distribution of and variation in human behaviours. Therefore, objective observation of earthquake video data can provide a useful quantitative measure of human behaviour. Significantly, the process will enable researchers to look more closely at behaviours, as well as the social and physical contexts associated with injury risk during and immediately following earthquake shaking.  相似文献   

Probabilistic Approach to Evaluation of Metal(loid) Fate During Stormwater Aquifer Storage and Recovery          下载免费PDF全文

Joanne L. Vanderzalm  Declan W. Page  Karen E. Barry  Kathleen Scheiderich  Dennis Gonzalez  Peter J. Dillon 《洁净——土壤、空气、水》2016,44(12):1672-1684

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Copper isotope fractionation during surface adsorption and intracellular incorporation by bacteria   总被引：1，自引：0，他引：1  

Navarrete JU  Borrok DM  Viveros M  Ellzey JT 《Geochimica et cosmochimica acta》2011,75(3):784-799

Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data which attempt to constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study, we utilized Cu isotopes (δ⁶⁵Cu) to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual representative species of Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, as well as with wild-type consortia of microorganisms from several natural environments. Ph-dependent adsorption experiments were conducted with live and dead cells over the pH range 2.5-6. Surface adsorption experiments of Cu onto live bacterial cells resulted in apparent separation factors (Δ⁶⁵Cu_{solution-solid} = δ⁶⁵Cu_solution − δ⁶⁵Cu_solid) ranging from +0.3‰ to +1.4‰ for B. subtilis and +0.2‰ to +2.6‰ for E. coli. However, because heat-killed bacterial cells did not exhibit this behavior, the preference of the lighter Cu isotope by the cells is probably not related to reversible surface adsorption, but instead is a metabolically-driven phenomenon. Adsorption experiments with heat-killed cells yielded apparent separation factors ranging from +0.3‰ to −0.69‰ which likely reflects fractionation from complexation with organic acid surface functional group sites. For intracellular incorporation experiments the lab strains and natural consortia preferentially incorporated the lighter Cu isotope with an apparent Δ⁶⁵Cu_{solution-solid} ranging from ∼+1.0‰ to +4.4‰. Our results indicate that live bacterial cells preferentially sequester the lighter Cu isotope regardless of the experimental conditions. The fractionation mechanisms involved are likely related to active cellular transport and regulation, including the reduction of Cu(II) to Cu(I). Because similar intracellular Cu machinery is shared by fungi, plants, and higher organisms, the influence of biological processes on the δ⁶⁵Cu of natural waters and soils is probably considerable.  相似文献   

Subaltern geopolitics: Introduction     

Joanne Sharp 《Geoforum》2011,42(3):271-273

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Tumbi Landslide, Papua New Guinea: rainfall induced?     

Joanne C. Robbins  Michael G. Petterson  Ken Mylne  Joseph O. Espi 《Landslides》2013,10(5):673-684

On 24 January 2012, a fatal landslide with an estimated volume of 3 Mm³ hit villagers and infrastructure in the Tagali Valley, Southern Highlands Province, Papua New Guinea (PNG). Although a moderate event by PNG standards, the associated human casualties and infrastructure destruction give a human as well as a scientific need to review the potential causes for the event. PNG experiences numerous landslides annually, most of which are trigged either by rainfall events or seismic activity. Here, we review the short-term rainfall patterns leading up to the slope failure at Tumbi Quarry and compare the rainfall accumulations obtained over durations of 30, 60 and 90 days prior to the landslide, with comparable rainfall accumulations obtained for other failures observed in PNG over a 12-year period. Additionally, a review of long-term rainfall over a period of 6 months prior to the failure is completed as well as an assessment of seismic activity. Based on our analysis, we believe a seismic trigger to be very unlikely, while the increase in rainfall in the 2 weeks prior to the failure in conjunction with a high-intensity rainfall event at the end of October 2011 could have had a greater influence in enhancing rather than restraining slope failure. This, in addition to natural denudational processes, geological structure and the anthropogenic activity in the vicinity of the landslide, could all have served to affect slope stability.  相似文献   

Influence of ambient flow around the horseshoe crabLimulus polyphemus on the distribution and orientation of selected epizoans     

Joanne Dietl  Carla Nascimento  Richard Alexander 《Estuaries and Coasts》2000,23(4):509-520

Cumulatively scored distributions of the slipper shell gastropodCrepidula sp., the sand-building polychaete wormSabellaria vulgaris, the calcareous meandering tubed polychaeteFilograna implexa, the barnacleSemibalanaus balanoides, and the lacy bryozoanSchizoporella sp. were mapped on a cm-square gridded silhouette of the prosoma, opisthosoma, and movable spines, and telson of the horseshoe crabLimulus polyphemus stranded on Reeds Beach, Cape May County, New Jersey in the Delaware Bay. Statistically tested and contoured epizoan frequencies for 81 males and 59 females revealed that slipper shells and agglutinated worm tubes are concentrated near the movable spines on the opisthosoma, but rare on recessed chilarial or opercular pleurites, the prosoma, and telson. Barnacles are disproportionately concentrated in entapophyseal pits on the opisthosoma and in the longitudinal furrows flanking the cardiac lobe of the prosoma. Bryozoans are concentrated near movable marginal spines of the opisthosoma, but also found on all areas of the prosoma, opisthosoma, and hinge area in between, as well as the telson. Different morphologic sites for their respective modal concentrations may result from competitive exclusion of bryozoans by barnacles. Genal angles have lower statistically predicted frequencies of bryozoans, barnacles, and sand worm tubes. Apertural openings of calcareous tubes are predominantly posteriorly oriented whereas the anterior magin of slipper shells are randomly oriented on the opisthosoma. Eschewing differential mortality, nonrandom distributions indicate possible: rugophilic (groove-seeking) larval settlement behavior for barnacles that preferred the recessed hinge area, longitudinal grooves, and pits; rheophilic (current-seeking) larval settlement behavior for the gastropods and tube-building polychaetes that filter feed in the eddies generated near the movable spines of the downcurrent-sloping opisthosoma; and geotactic (gravity-influenced) larval settlement or post-settlement migration to the vaulted crest (cardiac lobe). Deficiencies of protruding epizoic skeletons on the genal angles and anterior margin of the host may be due to removal by abrasion as the horseshoe crab plowed through sediment or shearing of the epizoans from the carapace substratum in strong currents or waves.  相似文献   

Regional magma plumbing and emplacement mechanisms of the Faroe‐Shetland Sill Complex: implications for magma transport and petroleum systems within sedimentary basins          下载免费PDF全文

Nick Schofield  Simon Holford  John Millett  David Brown  David Jolley  Simon R. Passey  Dave Muirhead  Clayton Grove  Craig Magee  Joanne Murray  Malcolm Hole  Christopher A.‐L. Jackson  Carl Stevenson 《Basin Research》2017,29(1):41-63

The movement of magma through the shallow crust and the impact of subsurface sill complexes on the hydrocarbon systems of prospective sedimentary basins has long been an area of interest and debate. Based on 3D seismic reflection and well data, we present a regional analysis of the emplacement and magmatic plumbing system of the Palaeogene Faroe‐Shetland Sill Complex (FSSC), which is intruded into the Mesozoic and Cenozoic sequences of the Faroe‐Shetland Basin (FSB). Identification of magma flow directions through detailed seismic interpretation of approximately 100 sills indicates that the main magma input zones into the FSB were controlled primarily by the NE–SW basin structure that compartmentalise the FSB into its constituent sub‐basins. An analysis of well data shows that potentially up to 88% of sills in the FSSC are <40 m in thickness, and thus below the vertical resolution limit of seismic data at depths at which most sills occur. This resolution limitation suggests that caution needs to be exercised when interpreting magmatic systems from seismic data alone, as a large amount of intrusive material could potentially be missed. The interaction of the FSSC with the petroleum systems of the FSB is not well understood. Given the close association between the FSSC and potential petroleum migration routes into some of the oil/gas fields (e.g. Tormore), the role the intrusions may have played in compartmentalisation of basin fill needs to be taken fully into account to further unlock the future petroleum potential of the FSB.  相似文献   

Methane emission measurements in urban areas in Eastern Germany     

Joanne H. Shorter  J. Barry Mcmanus  Charles E. Kolb  Eugene J. Allwine  Brian K. Lamb  Byard W. Mosher  Robert C. Harriss  Uwe Partchatka  Horst Fischer  Geoffrey W. Harris  Paul J. Crutzen  Hans-Josef Karbach 《Journal of Atmospheric Chemistry》1996,24(2):121-140

We have investigated methane emissions from urban sources in the former East Germany using innovative measurement techniques including a mobile real-time methane instrument and tracer release experiments. Anthropogenic and biogenic sources were studied with the emphasis on methane emissions from gas system sources, including urban distribution facilities and a production plant. Methane fluxes from pressure regulating stations ranged from 0.006 to 24. l/min. Emissions from diffuse sources in urban areas were also measured with concentration maps and whole city flux experiments. The area fluxes of the two towns studied were 0.37 and 1.9 g/m²/s. The emissions from individual gas system stations and total town emissions of this study are comparable to results of similar sites examined in the United States.  相似文献