Geology and the dark side

The diabolical and supernatural folklore traditions of geology are examined systematically for the first time. The following have all been suggested explanations for fossil remains: Devil's footprints, bones, toenails, fingers, thumbs, buttons, money and ninepins; Hobgoblin's claws; Fairy's fingers, heads, faces, hearts, beads, causeways, saltcellars, bottles, weights, money and loaves; elf arrows; witches’ beads and tongues. Twinned staurolite crystals have been called Fairy crosses.     

Pollutants,human health and the environment – A risk-based approach

Over the last 50 a there has been mounting unease about the risk of synthetic chemicals to human health. Publication of Rachel Carson’s Silent Spring in 1962 catalyzed public concern about chemicals. There is now a vast range of synthetic substances in the environment and their potential cocktail as well as the effects of chronic exposure is of concern. Concerns about pollution are not restricted to toxic chemicals, with radioactivity being an issue that continues to be emotive, and exposure to substances such as particulates has been seen to cause health problems. Improved understanding of chemical risks to the environment and human health suggest that a precautionary approach is adopted, with new approaches demonstrating how nature uses thousands of sustainable, non-toxic processes, which can be copied by industry. Policy has evolved from the prevention of local pollution to the holistic management of environmental quality. Regulation is now increasingly underpinned by risk assessment and responsibility for understanding and managing chemical risk is being transferred progressively to manufacturers and users. There is now an increased emphasis on individual responsibilities which requires a debate about the risks and benefits of chemicals in which all members of society can participate.     

The application of in vitro gastrointestinal extraction to assess oral bioaccessibility of potentially toxic elements from an urban recreational site

The use of in vitro gastrointestinal extraction to assess the oral bioaccessibility of 7 potentially toxic elements (PTEs) from soil derived from an urban recreational site, has been assessed. The pseudo-total concentration of the 7 PTEs was determined using microwave digestion followed by inductively coupled plasma mass spectrometry. The bioaccessible fraction was determined and the data compared to the pseudo-total concentrations to determine % bioaccessibility. A generic quantitative risk assessment (GQRA) was undertaken on the pseudo-total PTE concentration of the site by comparing the values with soil guideline (SGV) or generic assessment criteria (GAC) using the residential land use scenario. Based on the GQRA, concentrations of 3 of the PTEs investigated within the soils could present a potential risk to site users. Consideration of receptor exposure and bioaccessibility data allowed a more considered approach to human-health risk assessment at this site. Although the bioaccessibility data did not significantly alter the sites preliminary designation as contaminated (As and Pb concentrations exceeded the GAC even in the in vitro extracts) bioaccessibility data are clearly an additional tool towards furthering our understanding of human-health risk at contaminated sites and have the potential to act as a pragmatic decision-support tool.     

High-resolution observations of aggregate flux during a sub-polar North Atlantic spring bloom

An aggregate flux event was observed by ship and by four underwater gliders during the 2008 sub-polar North Atlantic spring bloom experiment (NAB08). At the height of the diatom bloom, aggregates were observed as spikes in measurements of both particulate backscattering coefficient (b_bp) and chlorophyll a fluorescence. Optical sensors on the ship and gliders were cross-calibrated through a series of simultaneous profiles, and b_bp was converted to particulate organic carbon. The aggregates sank as a discrete pulse, with an average sinking rate of ∼75 m d⁻¹; 65% of aggregate backscattering and 90% of chlorophyll fluorescence content was lost between 100 m and 900 m. Mean aggregate organic carbon flux at 100 m in mid-May was estimated at 514 mg C m⁻² d⁻¹, consistent with independent flux estimates. The use of optical spikes observed from gliders provides unprecedented coupled vertical and temporal resolution measurements of an aggregate flux event.     

Seasonal and Inter-annual Patterns in Primary Production,Respiration, and Net Ecosystem Metabolism in Three Estuaries in the Northeast Gulf of Mexico

Measurements of primary production and respiration provide fundamental information about the trophic status of aquatic ecosystems, yet such measurements are logistically difficult and expensive to sustain as part of long-term monitoring programs. However, ecosystem metabolism parameters can be inferred from high frequency water quality data collections using autonomous logging instruments. For this study, we analyzed such time series datasets from three Gulf of Mexico estuaries: Grand Bay, MS; Weeks Bay, AL; and Apalachicola Bay, FL. Data were acquired from NOAA's National Estuarine Research Reserve System Wide Monitoring Program and used to calculate gross primary production (GPP), ecosystem respiration (ER), and net ecosystem metabolism (NEM) using Odum's open water method. The three systems represent a diversity of estuaries typical of the Gulf of Mexico region, varying by as much as two orders of magnitude in key physical characteristics, such as estuarine area, watershed area, freshwater flow, and nutrient loading. In all three systems, GPP and ER displayed strong seasonality, peaking in summer and being lowest during winter. Peak rates of GPP and ER exceeded 200 mmol O₂?m^?2 day^?1 in all three estuaries. To our knowledge, this is the first study examining long-term trends in rates of GPP, ER, and NEM in estuaries. Variability in metabolism tended to be small among sites within each estuary. Nitrogen loading was highest in Weeks Bay, almost two times greater than that in Apalachicola Bay and 35 times greater than to Grand Bay. These differences in nitrogen loading were reflected in average annual GPP rates, which ranged from 825 g C m^?2 year^?1 in Weeks Bay to 401 g C m^?2 year^?1 for Apalachicola Bay and 377 g C m^?2 year^?1 in Grand Bay. Despite the strong inter-annual patterns in freshwater flow and salinity, variability in metabolic rates was low, perhaps reflecting shifts in the relative importance of benthic and phytoplankton productivity, during different flow regimes. The advantage of the open water method is that it uses readily available and cost-effective sonde monitoring technology to estimate these fundamental estuarine processes, thus providing a potential means for examining long-term trends in net carbon balance. It also provides a historical benchmark for comparison to ongoing and future monitoring focused on documenting the effect of human activities on the coastal zone.     

Seagull Lake, Western Eyre Peninsula, South Australia: A Saline Lake to Benefit from Climate Change? Geomorphology, Invertebrates, Birds and the Future

正Seagull Lake is an unusual saline lake,having a marine spring connected to a large continental ecosystem.With climate change the balance between the two is likely to change.This lake originated about 6000 years ago as a     

Seasonal Oxygen Dynamics in a Warm Temperate Estuary: Effects of Hydrologic Variability on Measurements of Primary Production,Respiration, and Net Metabolism

Seasonal responses in estuarine metabolism (primary production, respiration, and net metabolism) were examined using two complementary approaches. Total ecosystem metabolism rates were calculated from dissolved oxygen time series using Odum’s open water method. Water column rates were calculated from oxygen-based bottle experiments. The study was conducted over a spring-summer season in the Pensacola Bay estuary at a shallow seagrass-dominated site and a deeper bare-bottomed site. Water column integrated gross production rates more than doubled (58.7 to 130.9 mmol O₂ m^?2 day^?1) from spring to summer, coinciding with a sharp increase in water column chlorophyll-a, and a decrease in surface salinity. As expected, ecosystem gross production rates were consistently higher than water column rates but showed a different spring-summer pattern, decreasing at the shoal site from 197 to 168 mmol O₂ m^?2 day^?1 and sharply increasing at the channel site from 93.4 to 197.4 mmol O₂ m^?2 day^?1. The consistency among approaches was evaluated by calculating residual metabolism rates (ecosystem ? water column). At the shoal site, residual gross production rates decreased from spring to summer from 176.8 to 99.1 mmol O₂ m^?2 day^?1 but were generally consistent with expectations for seagrass environments, indicating that the open water method captured both water column and benthic processes. However, at the channel site, where benthic production was strongly light-limited, residual gross production varied from 15.7 mmol O₂ m^?2 day^?1 in spring to 86.7 mmol O₂ m^?2 day^?1 in summer. The summer rates were much higher than could be realistically attributed to benthic processes and likely reflected a violation of the open water method due to water column stratification. While the use of sensors for estimating complex ecosystem processes holds promise for coastal monitoring programs, careful attention to the sampling design, and to the underlying assumptions of the methods, is critical for correctly interpreting the results. This study demonstrated how using a combination of approaches yielded a fuller understanding of the ecosystem response to hydrologic and seasonal variability.     

Return migration of 1.5 generation Korean New Zealanders: Short‐term and long‐term motives

Through in‐depth interviews and participant observation with 40 1.5 generation Korean New Zealander returnees, we explore life trajectories and identify both short‐ and long‐term reasons for return. Short‐term reasons for return include moving home when entering adulthood in order to begin a career, gaining new experiences and finding a future spouse. Longer term influences include the difficulties of living as minority‐status immigrants in the host society, transnational connections and a longing for a sense of ‘home’. Our consideration of longer term migration strategies sheds light upon the often forgotten difficulties and complexities that can underlie an individual's return.     

Subglacial clast behaviour and its implication for till fabric development: new results derived from wireless subglacial probe experiments

This study has investigated the three-dimensional movement of clasts within deformation till, using embedded wireless probes. These probes were part of an environmental sensor network, which measured subglacial properties (temperature, water pressure, resistivity, case strain and tilt) six times a day, and relayed that data via radio to the glacier surface, where they were forwarded and broadcast on-line. The system was installed at Briksdalsbreen, Norway and operated from August 2004 until August 2006. Approximately 2000 probe days worth of data were collected, with an increase in performance (41% more readings) during the second year. The probes showed similar patterns of water pressure rises throughout the two years, but with slightly different magnitudes and timings. These changes in water pressure could be related to clast behaviour. The probes decreased their dip over the year, and the rate of change was related to an increase in glacier velocity. After initial changes in dip, the probes experienced changes in orientation, followed by rotation about the a-axis. This continuous rotation was similar to the motion suggested by Jeffery [1922. The motion of ellipsoidal particles immersed in a viscous fluid. Proceedings of the Royal Society of London, Series A 102, 161–179] for the behaviour of clasts within a viscous material. In addition, some probes also showed short, frequent dip oscillations in spring and autumn, which were interpreted to reflect stick-slip events, similar to lodging; and demonstrated how local conditions can interrupt the predicted rotation pattern.Overall, it is demonstrated that when water pressures were high, decoupling occurred associated with basal sliding and dip oscillations; and when water pressures fell, the ice and sediment were coupled and till deformation occurred. These events happened during summer and autumn. It is this combination of “lodgement” and deformation that builds up both a complex (but predictable) fabric and a resultant composite till sedimentology.