TRANSFORMATION PATTERNS OF SUBAERIAL MICRO-TIDAL BEACHES

Seven subaerial, low energy beaches in the SE Mediterranean were surveyed biweekly for 13 months. Beach level data were computer-processed and plotted as time-series profile diagrams that differentiated the subaerial beach into three basic subenvironments: backshore, berm, and swash-zone. Heterogeneous seasonal trends in beach sand budget, erosion/accretion patterns, occurrence of ridges and berm-crests, and in pollution by seaborne tar were observed. The profile stations also showed very different degrees of seasonality, although located along similar beaches. Local beachrock protection, when evident, effectively masked seasonality by significantly lowering beach dynamics. Biweekly, seasonal, and annual fluctuations of the beach sand-budget were computed. Average annual net sand flux at the seven beaches was 66 m³/m of beach front, though wide variations occurred. Annual changes in the sand budget along the study area exceeded volumetric changes within the profile, indicating longshore sand transfer. Synchronism of beach behavior prevailed only at the seasonal level. However, intra-seasonal fluctuations for the different profile stations were out of phase, indicating poor synchronism of beach response due to longshore movement of rhythmic topography. Profile changes were thus often unrelated to concomitant wave-climate changes. The overall heterogeneous beach response was in sharp contrast to the identical wave climate, similar bathymetry, and sedimentology of the studied beaches.     

Economical digital photomicroscopy

Public domain software has been developed for remote exposure control of a consumer digital camera for use in photomicroscopy. A computer-controlled shutter release and remote control of various camera functions are essential to avoid mechanical disturbance of the microscope and slide during the imaging procedure. These features have previously been available only with expensive professional models. The digital images of diatom specimens obtained with this system captured the same detail as conventional photographs. The setup can therefore be used as a cost-effective tool for documenting taxonomic information of microscopically small organisms. In combination with the fast data transfer rates available via the Internet, microscopical studies can now be performed faster, more reliably, and more consistently.     

Alkalinity production as an indicator of failure in steel slag leach beds treating acid mine drainage

Acid mine drainage is a serious environmental problem throughout mining regions of the US and around the world. In Appalachia, reuse of steel slag from steel production as a source of alkalinity for treatment of acid mine drainage has become a common practice. In these systems, dubbed steel slag leach beds, relatively clean surface water is percolated through a bed of steel slag to add large amounts of alkalinity to the water before mixing it with acidic, metalliferous mine water. These beds do not operate consistently and their failure mechanisms are poorly understood. Using the experience of Raccoon Creek watershed in southern Ohio, the alkalinity distribution of the discharge of six steel slag leach beds is compared. Two of these beds are still functional, one has been abandoned and three are operating poorly. The difference in alkalinity distribution between these beds suggests that a carbonate-dominated alkalinity system is an indicator of a poorly performing steel slag leach bed, while a more even distribution between hydroxide, carbonate and bicarbonate may point to more ideal operating conditions. In eight laboratory column experiments, this evidence was then expanded upon by testing different mixed media substrates (differing mixes of steel slag, wood chips and river gravel) to see which provided the most ideal alkalinity distributions. The columns that had steel slag mixed either with wood chips or wood chips and river gravel outperformed the column with slag only in terms of alkalinity distribution, perhaps due to microbial processes or increased hydraulic conductivity without significant added calcium or carbon that could drive calcium carbonate precipitation within the beds and causing them to fail.     

The Getting of the Nganabbarru: Observations and reflections on Aboriginal buffalo hunting in northern Australia

Nganabbarru , or water buffalo ( Bubalus bubalis ), is frequently hunted by Aboriginal men, and buffalo meat is an important food source for many Arnhem Land Aboriginal communities. The experience of buffalo hunting trips with Aboriginal men who reside at Korlohbidahdah outstation in central Arnhem Land is used as a point of departure to consider the relationships between Aboriginal people and megaherbivores in the past and the present, and to explore the complexity of feral animal management in cross-cultural settings. This enquiry raised the question of the cultural conception of feral animals and demonstrates that there is no simple answer to the question: what is a buffalo? Buffaloes have been the focus of a colonial economic industry and are iconic of the Territorian way of life. However, they spread economically significant livestock diseases and cause widespread environmental damage. In the 1980s feral buffalo populations were the target of the Brucellosis and Tuberculosis Eradication Campaign (BTEC) control program. The failure to continue control programs following the cessation of BTEC program and inadequate consultation with Aboriginal landowners has meant that today's land managers are once again faced with conflicting views about controlling feral buffalo populations on Aboriginal land and within National Parks like Kakadu. It is concluded that there are genuine, previously overlooked opportunities for cross-cultural collaboration in managing feral buffaloes. Cross-disciplinary research involving ecologists, anthropologists, linguists, economists and environmental historians is required to help develop sustainable and culturally appropriate feral animal control programs.     

Characterization of coal-mine refuse as backfilling material

Summary With increased production and more stringent regulations for air, water and ground pollution control, the safe and environmentally acceptable disposal of coal-mine refuse is becoming ever more demanding. Backfilling may provide an environmentally acceptable method for the disposal of waste materials. Increased resource recovery, enhanced ventilation control, and minimizing surface subsidence, underground coal-mine fires and spontaneous combustion of coal are potential advantages of backfilling. In this paper the physical and mechanical properties of coal-mine waste from different sites are described and the effects of these properties on the duty requirements of fill material are assessed. As a result of testing, it is concluded that if improving ground control is the only reason for backfilling, coal refuse alone does not appear to be a suitable stowing material. If coal-refuse disposal is also a consideration, then it may be more attractive as a stowing material.     

Geographies on the Move: A Practical and Theoretical Approach to the Mobile Interview

This article considers the mobile interview method's utility to geography through five strengths: the ability to (1) produce spatially grounded and place-specific data, (2) access subtler and more complex meanings of place, (3) create opportunities for flexible and collaborative conversation with participants in situ, (4) build rapport and adjust participant–researcher power dynamics, and (5) efficiently produce rich geographic data. Practical, technical, ethical, and epistemological considerations are discussed. We expand methodological exploration of disempowered individuals' experiences of home, neighborhood, and urban space. The mobile interview offers a valuable, underutilized method for geographers to better understand the coconstitutive relationship between self and place.     

Ionospheric spread-F at Huancayo,sunspot activity and geomagnetic activity

A superposed-epoch method is used to investigate the occurrence of spread-F at Huancayo relative to days of high sunspot activity and also relative to days of high geomagnetic activity. A good correlation is found between days of high A_p, index and high spread-F occurrence for a pre-sunrise interval of a few hours. When 3-hourly K_p indices are used they show a peak value approximately 6 hr prior to an above-average occurrence of spread-F. It is suggested that this pre-sunrise spread-F is associated with ionospheric height rises which are produced by travelling disturbances, initiated in polar regions at times of high geomagnetic activity.     

Some aspects of Sporadic-E at mid-latitudes

Evidence is presented to suggest that the ƒ₀E_s value tends to be high at positions in the E_s-layer where trough slope-lines and crest slope-lines of F2-layer irregularities meet the E_s-layer. These slope-lines are drawn through the troughs and crests, respectively, of the characteristic kinks in the F2-layer ionization contours, which are associated with F2-layer irregularities.

A rotating-loop direction-finding system has allowed an estimation of the distribution of ionization, which gives rise to Sporadic-E echoes. Analysis of Sporadic-E occurrence, on two occasions, suggests that the reflecting surfaces are frontal in nature, the fronts having a separation from each other of some tens of kilometres, and probably existing as closed curves, with diameters of the order of several hundreds of kilometres. A possible association between these structures and the occurrence of the green line of the airglow, is discussed.

A distribution of ionization, which will give contours showing “clouds” of ionization at some frequencies and a ripple structure at other frequencies, is proposed, in an endeavour to explain the apparent dual nature of Sporadic-E occurrence.

The evidence seems to indicate that the mechanism operating at the E_s-layer level, producing the phenomenon of Sporadic-E, is the same as that which produces the F2-layer irregularities which are responsible for “Spread-F”.