Geological context of potential landing site of the Luna-Glob mission

The region planned for performing the Luna-Glob mission is located in the southern part of the swell surrounding the largest South Pole-Aitken (SPA) basin. The photogeological analysis of the surface topography of this region using the LRO-WAC (resolution of 100 Mpxl) photomaps made it possible to define the following groups of morphological units (area types): (1) related to the formation of relatively fresh impact craters; (2) associated with larger (>100 km across) degraded craters including (2a) external and (2b) inner facies; and (3) occupying intercrater spaces. The comparison of the geological map with the map illustrating the distribution of the epithermal neutron flow (Mitrofanov et al., 2012) shows no correlation between them. Consequently, one should not expect development of rock complexes, which would be characterized by elevated concentrations of water in the region chosen for the Luna-Glob mission and, thus, considered among the first-priority targets. The comparison of the neutron flow distribution with the map of circular polarization of the Mini-RF radar beam also shows no correlation. This means that high values of circular polarization reflect elevated concentrations of rock fragments rather than water accumulations. Even though ice fragments are present, their sizes should only slightly be less as compared with the radar wavelength (12.6 cm). The region planned for investigations in the scope of the Luna-Glob mission corresponds to the swell of the largest (and, likely, oldest) preserved basin and offers a potential opportunity to analyze ancient material of this planet and introduce important constraints into the spectrum of models proposed for explaining the Moon’s origin.     

Application of numerical modelling in the design of a full‐scale heated Tunnel Sealing Experiment

The Tunnel Sealing Experiment (TSX) was a full‐scale in situ demonstration of technology for constructing nearly water tight‐seals in excavations through crystalline rock deep below the surface of the earth. The experiment has been carried out at Atomic Energy of Canada Limited's (AECL's) Underground Research Laboratory near Lac du Bonnet, Canada, in support of international programs for geologic disposal of radioactive waste. The TSX, with partners from Canada, Japan, France and the United States, was carried under conditions of high pressure (up to 4 MPa) and elevated temperature (up to 85°C). Comparing numerical model predictions with eight years of data collected from approximately 900 sensors was an important component of this experiment. Model of Transport In Fractured/porous Media (MOTIF), a finite element computer program developed by AECL for simulating fully coupled or uncoupled fluid flow, solute transport and heat transport, was used to model both the ambient temperature and heated phases of the TSX. The plan to heat the water in the TSX to 85°C was developed using model predictions and a comparison of simulated results with measurements during heating of the water in the TSX to about 50°C. The three‐dimensional MOTIF simulations were conducted in parallel with axisymmetric modelling using Fast Lagrangian Analysis of Continua (FLAC), which computed the heat loss from pipes that carried the heated water through the rock to and from the experiment. The numerical model was initially used to develop a plan for operation of the experiment heaters, and then subsequently used to predict temperatures and hydraulic heads in the TSX bulkhead seals and surrounding rock. Copyright © 2005 John Wiley & Sons, Ltd.     

Adaptation of the antioxidant defence system in hydrothermal-vent mussels (Bathymodiolus azoricus) transplanted between two Mid-Atlantic Ridge sites

The vent mussel Bathymodiolus azoricus is the dominant member of the Northern Mid‐Atlantic Ridge (MAR) hydrothermal megafauna, and lives in an environment characterized by temporal and spatial variations in the levels of heavy metals, methane and hydrogen sulphide, substances which are known to increase reactive oxygen species levels in the tissues of exposed organisms. To evaluate the effects of two contrasting hydrothermal environments on the antioxidant defence system of this vent mussel species, a 2‐week transplant experiment was carried out involving mussels collected from the relatively deep (2300 m), and chemical rich, Rainbow vent field. These were transplanted to the shallower (1700 m), and relatively less toxic, Lucky Strike vent field. To achieve this objective, levels of superoxide dismutase, catalase (CAT), total glutathione peroxidase (GPx), selenium‐dependent glutathione peroxidase and lipid peroxidation (LPO) were measured in the gills and mantle tissues of resident and transplant mussels before and after the transplant experiment. With the exception of CAT, the gills of the transplanted mussels had significantly higher antioxidant enzyme activity compared with the basal levels in the donor (Rainbow) and recipient (Lucky Strike) populations; whereas the antioxidant enzyme levels in the mantle tissues of the transplants reflected the baseline levels of activity in the native Lucky Strike mussels after 2 weeks. In contrast, LPO levels were significantly higher in both tissue types in the transplants than in either the source or the recipient populations, which suggested a response to hydrostatic pressure change (note, the transplant animals were brought to the surface for transportation between the two vent fields). The fact that the Rainbow mussels survived the transplant experience indicates that B. azoricus has a very robust constitution, which enables it to cope behaviourally, physiologically and genetically with the extreme conditions found in its naturally contaminated deep‐sea environment.     

Mexico City subsidence observed with persistent scatterer InSAR

We analyzed 23 satellite SAR (synthetic aperture radar) scenes using Persistent Scatter Interferometry (PSI) to study subsidence in Mexico City associated with groundwater withdrawal. The data were acquired by the Envisat ASAR system between January 2004 and July 2006. The spatial pattern of subsidence and the maximum subsidence rate (300 mm/year) are similar to earlier studies. Comparison to independent GPS data indicates RMS agreement between the two techniques of 6.9 mm/year, about the level expected based on joint data uncertainty. Significant annual variation in the GPS vertical data is not observed, suggesting minimal aquifer recharge during the rainy season, and justifying a simple linear model of phase variation through time for the PSI analysis.     

Airborne Microorganisms Emitted from Wastewater Treatment Plant Treating Domestic Wastewater and Meat Processing Industry Wastes

Experiments were conducted to study the airborne microbial contamination generated by a wastewater treatment plant (WWTP). Aerosol samples were collected simultaneously, by sedimentation and impact methods, from the area and the surroundings of the WWTP. Total colony forming units (CFUs) of heterotrophic bacteria (HPC), as well as members of the Enterobacteriaceae, staphylococci, enterococci, actinomycetes, and microscopic fungi were determined. Bacterial (HPC) concentrations ranged between 10¹ and 10⁴ CFU/m³, fungi 0 and 10⁴ CFU/m³. Higher numbers of HPC bacteria in air samples were observed in summer, fungi in autumn. The main emission of microorganisms to atmospheric air was from the mechanical sewage treatment devices of the WWTP. The facilities of the biological sewage treatment of the plant did not generate large amounts of bioaerosols. In the air obtained from the premises of the WWTP, 25 species of the Enterobacteriaceae were isolated (Salmonella spp., Klebsiella pneumoniae, Escherichia coli). At the fence and in the surroundings only Pantoea spp. were identified. This suggests that the sewage bacteria were mainly discharged in the area of the WWTP. The presence of enteric bacteria, especially Enterobacteriaceae reflects the level of air pollution with bioaerosols from sewage and is an important factor during monitoring the quality of the air around WWTPs.     

SOIL GEOMORPHOLOGY AS AN INTEGRATIVE APPROACH IN PHYSICAL GEOGRAPHY: A REVIEW OF FOUR RECENT BOOKS

Relict barrier beaches occur around the margins of many former pluvial lakes in the California desert. In common with modern barrier beaches along ocean coasts, these relict barriers possess geometric and compositional properties indicative of beach-forming processes, notably waves and currents. Because lake waves are a direct response to wind action, past wave climates may in turn be used to infer paleowind regimes. Where beaches of known age occur, wave climates and wind regimes may be invoked for specific time intervals. Using barrier beaches from former Lake Mojave and Lake Manly, this paper explores the extent to which the above theory may be applied to invoke past processes and wind regimes. The data indicate beach emplacement mainly by wave-related accretion and overwash generated by winds similar in direction to those of today, doubtless influenced then as now by topographic corridors. However, textural properties, predicted wave heights and entrainment velocities indicate that sustained southerly winds were probably twice as strong (by a factor ranging from 1.2 to 2.2 or more) and probably more persistent than today, at least towards the close of pluvial conditions. [Key words: barrier beaches, wave climate, paleoclimate, paleowinds, pluvial lakes, Quaternary, California desert.]     

Peat depth as a control on moss water availability under evaporative stress

Northern peatlands are a vital component of the global carbon cycle, containing large stores of soil organic carbon and acting as a long‐term carbon sink. Moss productivity is an important factor in determining whether these wetlands will retain this function under future climatic conditions. Research on unsaturated water flow in peatlands, which controls moss productivity during periods of evaporative stress, has focused on relatively deep bog systems. However, shallower peatlands and marginal connective wetlands can be essential components of many landscape mosaics. In order to better understand factors influencing moss productivity, water balance simulations using HYDRUS‐1D were run for different soil profile depths, compositions, and antecedent moisture conditions. Our results demonstrate a bimodal distribution of peatland realizations, either primarily conserving water by limiting evapotranspiration or maximizing moss productivity. For sustained periods of evaporative stress, both deep water storage and a shallow initial water table delay the onset of high vegetative stress, thus maximizing moss productivity. A total depth of sand and peat of 0.8 m is identified as the threshold above which increasing peat depth has no effect on changing vegetative stress response. In contrast, wetlands with shallow peat deposits (less than 0.5 m thick) are least able to buffer prolonged periods of evaporation due to limited labile water storage and will thus quickly experience vegetative stress and so limit evaporation and conserve water. With a predicted increase in the frequency and size of rain events in continental North America, the moss productivity of shallow wetland systems may increase, but also greater moisture availability will increase the likelihood they remain as wetlands in a changing climate.     

The effects of river restoration on catchment scale flood risk and flood hydrology

A rising exposure to flood risk is a predicted consequence of increased development in vulnerable areas and an increase in the frequency of extreme weather events due to climate change. In the face of this challenge, a continued reliance on engineered at‐a‐point flood defences is seen as both unrealistic and undesirable. The contribution of ‘soft engineering’ solutions (e.g. riparian forests, wood in rivers) to integrated, catchment scale flood risk management has been demonstrated at small scales but not larger ones. In this study we use reduced complexity hydrological modelling to analyse the effects of land use and channel changes resulting from river restoration upon flood flows at the catchment scale. Results show short sections of river‐floodplain restoration using engineered logjams, typical of many current restoration schemes, have highly variable impacts on catchment‐scale flood peak magnitude and so need to be used with caution as a flood management solution. Forested floodplains have a more general impact upon flood hydrology, with areas in the middle and upper catchment tending to show reductions in peak magnitude at the catchment outflow. The most promising restoration scenarios for flood risk management are for riparian forest restoration at the sub‐catchment scale, representing 20–40% of the total catchment area, where reductions in peak magnitude of up to 19% are observed through de‐synchronization of the timings of sub‐catchment flood waves. Sub‐catchment floodplain forest restoration over 10–15% of total catchment area can lead to reductions in peak magnitude of 6% at 25 years post‐restoration. Copyright © 2016 John Wiley & Sons, Ltd.     

Carbon dioxide fluxes and DOC concentrations of eroding blanket peat gullies

UK peatlands are affected by severe gully erosion with consequent impacts on ecosystem services from these areas. Incision into the peat can damage the vegetation and hydrology and lead to increases in carbon loss and sediment transfer downstream. Gullies represent then a conduit for and a hotspot of carbon loss but the relatively high water tables of gullies have meant that they have been identified as areas with a high restoration potential because of easily restored peat‐forming conditions. This study uses a series of gully sites, subject to different restoration interventions, to investigate differences in carbon pathways (DOC, CO₂) and hydrology between restoration strategies and gully position. The results show that the position within the gully (interfluve, gully side, or gully floor) does not significantly affect water quality but that it plays a significant role in CO₂ exchange. Gully floors are areas of high photosynthesis and ecosystem respiration, though net ecosystem exchange is not significantly different across the gully. While gully position plays a role in the cycling of some carbon species, this study highlights the importance of vegetation as a key control on carbon cycling. Copyright © 2012 John Wiley & Sons, Ltd.