Possible evidence for on-going volcanism on Mars as suggested by thin, elliptical sheets of low-albedo particulate material around pits and fissures close to Cerberus Fossae

High quality CCD images obtained at two different observatories in North Italy allowed the identification of four morphological structures near the nuclear region of the comet Ikeya-Zhang (I-Z): haloes, jets, shells and spirals. The interpretation of the nature of these structures has been attempted by means of a comparison of different up-to-date image processing techniques, which led to a single common estimate of the rotation period (p=1.48±0.20 days).     

The 3410 Å band of the PH molecule in the solar photospheric spectrum

Some weak unidentified solar photospheric lines in the wavelength range: (3400–3465) Å may be due to PH lines of the (0, 0) band of the PH(A ³ _i - X ^{3 -})system. These faint PH molecular lines have resulted an excitation temperature of the order of 4500 K. Using experimental lifetime data for PH in the A ³ _i state, an absorption oscillator strength f ₀₀ = 0.0075 is derived for the 3410 Å band of the PH (A ³ _i - X ^{3 -})system. Accurate line positions, oscillator strength and transition probability for the 4.4 fundamental rotation-vibration band of the PH molecule are obtained. A comparison of positions of some lines of the 4.4 band with those obtained on new tracings of high resolution solar spectra shows many coincidences with weak solar lines.     

Pollen analysis of faeces as a method of demonstrating seasonal variations in the diet of Svalbard reindeer (Rangifer tarandus platyrhynchus)

Analysis of the pollen and spore content of 40 fresh samples of faeces collected from Svalbard reindeer during 1994/5 and 1996 shows variations among and within seasons, with distinct species/pollen types dominating each season. Winter samples were characterized by high amounts of Salix and moss spores , while spring samples contained decreasing amounts of the plants grazed in winter and increasing values of species grazed in summer, such as Oxyria digyna and Pedicualaris spp. Summer samples had a large quantity of pollen and a great number of pollen types. Autumn samples indicated that grasses are the most important forage species in this period. The seasonally varying proportions of pollen types are related to such factors as plant phenology, abudance, palatability and nutritional quality, as well as the prefereence of reindeers for grazing in low, wet areas in the summer but on higher, wind-blown ridges during the winter. The results mostly confrim other studies of Svalbard reindeer diet and grazing behaviour. The advantages and limitations of the pollen analysis method for such investigations are discussed.     

Landscape care paradoxes: Swedish landscape care arrangements in a European context

Contemporary European agriculture has a number of additional aims beside of food production, such as safeguarding environmental services and conservation values. Substantial efforts at official levels are aimed towards sustainable development but also towards maintaining values of what may be termed vanishing landscapes. Selected areas and landscape features are set aside for protection or restoration. Individual efforts of this type have a long history in Sweden, and the issue has recently received increased attention, primarily due to more ambitious government goals concerning biodiversity conservation and Sweden’s ratification of the European Landscape Convention. This has resulted in an increased scientific and official interest in vanishing values in the rural landscape, where parts of Eastern Europe, such as the Maramures district in Romania, have been used as model examples of land use regimes which in the past was common in Sweden. In this context, the dilemma of romanticizing peasants’ use of land is highlighted and discussed more than has hitherto been done. This paper sheds light on some paradoxes inherent in official policies in relation to land use practices concerning the management of rural landscapes in Sweden, and relates the Swedish situation to a contrasting example of landscape practice in Romania. We discuss the concept of landscape care in relation to the construction and perception of landscape values and valuable landscapes through the lenses of rural realities and official policies. When Swedish authorities engage in the promotion of landscape care, they tend to work with slices of land, specific predefined values and individual farmers, and they often disregard the need to treat the landscape as a socio-ecological complex dynamic in space and time. We discuss how environmental policy generally could be improved through the adoption of a more inclusive and flexible approach towards aiding the different aims inherent in multifunctional rural landscapes.     

Multiple drivers of Holocene lake level changes at a lowland lake in northeastern Germany

Many German lakes experienced significant water level declines in recent decades that are not fully understood due to the short observation period. At a typical northeastern German groundwater‐fed lake with a complex basin morphology, an acoustic sub‐bottom profile was analysed together with a transect of five sediment cores, which were correlated using multiple proxies (sediment facies, μ‐XRF, macrofossils, subfossil Cladocera). Shifts in the boundary between sand and mud deposition were controlled by lake level changes, and hence, allowed the quantification of an absolute lake level amplitude of ~8 m for the Holocene. This clearly exceeded observed modern fluctuations of 1.3 m (AD 1973–2010). Past lake level changes were traced continuously using the calcium‐record. During high lake levels, massive organic muds were deposited in the deepest lake basin, whereas lower lake levels isolated the sub‐basins and allowed carbonate deposition. During the beginning of the Holocene (>9700 cal. a BP), lake levels were high, probably due to final melting of permafrost and dead‐ice remains. The establishment of water‐use intensive Pinus forests caused generally low (3–4 m below modern) but fluctuating lake levels (9700–6400 cal. a BP). Afterwards, the lake showed an increasing trend and reached a short‐term highstand at c. 5000 cal. a BP (4 m above modern). At the transition towards a cooler and wetter late Holocene, forests dominated by Quercus and Fagus and initial human impact probably contributed more positively to groundwater recharge. Lake levels remained high between 3800 and 800 cal. a BP, but the lake system was not sensitive enough to record short‐term fluctuations during this period. Lake level changes were recorded again when humans profoundly affected the drainage system, land cover and lake trophy. Hence, local Holocene water level changes reflect feedbacks between catchment and vegetation characteristics and human impact superimposed by climate change at multiple temporal scales.     

Gendered labour arrangements in Switzerland: Structures, cultures, meanings: statistical evidence and biographical narratives

In this paper we explore the role of culture in the reproduction of gendered labour arrangements. Using Switzerland as an example, we first analyse statistical data on paid and unpaid labour. We look at differences between women and men, but also between different types of regions. Patterns emerge to support our hypothesis that beyond structures of economic opportunity, economic cycles and welfare state provisions, local (gender) culture might explain some of the particularities of gendered labour arrangements. The argument is reinforced by data on regional voting patterns in a recent referendum on the issue of maternity leave. In the second part, we further explore these issues by looking at a particular place and re-telling work-life-stories that show how two women navigate between different working culture environments in accordance with their life-cycle needs and individual ideas and values. Finally, we discuss issues of scale and methodology and reflect on the significance of varying local working environments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Kaolinitic meniscus bridges as an indicator of early diagenesis in Nubian sandstones, Sinai, Egypt

Characteristic meniscus geometries formed by kaolinitic infiltration are observed in Nubian sandstones collected on the western coast of the Sinai Peninsula (Egypt). Based on petrographic and scanning electron microscope (SEM) observations, the kaolinite forming the menisci consists of mixed-size discrete platelets that gather into the corners around the framework grain-to-grain contacts. Specifically, the internal fabric of menisci indicates a general organizing trend from (1) the centre, where the platelets coat the framework grains; (2) to the peripheral zone, where they are oriented tangentially to grain surfaces; (3) to the pore linings with curvatures that are consistent with theoretical considerations of air–water interfaces. This typical arrangement suggests a detrital origin of kaolinite platelets by mechanical infiltration into sediments lying above the tablewater, in vadose conditions. This type of clay cementation occurring during early diagenesis can prevent (delay) deep burial diagenetic processes and therefore preserve excellent reservoir properties.     

Interindividual variability and ontogenetic effects on Mg and Sr incorporation in the planktonic foraminifer Globigerinoides sacculifer

In order to investigate the interindividual and ontogenetic effects on Mg and Sr incorporation, magnesium/calcium (Mg/Ca) and strontium/calcium (Sr/Ca) ratios of cultured planktonic foraminifera have been determined. Specimens of Globigerinoides sacculifer were grown under controlled physical and chemical seawater conditions in the laboratory. By using this approach, we minimised the effect of potential environmental variability on Mg/Ca and Sr/Ca ratios. Whereas temperature is the overriding control of Mg/Ca ratios, the interindividual variability observed in the Mg/Ca values contributes 2-3 °C to the apparent temperature variance. Interindividual variability in Sr/Ca ratios is much smaller than that observed in Mg/Ca values. The variability due to ontogeny corresponds to −0.43 mmol/mol of Mg/Ca ratio per chamber added. This translates into an apparent decrease of ∼1 °C in Mg/Ca-based temperature per ontogenetic (chamber) stage. No significant ontogenetic effect is observed on Sr incorporation. We conclude that the presence of a significant ontogenetic effect on Mg incorporation can potentially offset Mg/Ca-based temperature reconstructions. We propose two new empirical Mg/Ca-temperature equation based on Mg/Ca measurements of the last four ontogenetic (chamber) stages and whole foraminiferal test: Mg/Ca = (0.55(±0.03) − 0.0002(±4 × 10⁻⁵) MSD) e^0.089T and, Mg/Ca = (0.55(±0.03) − 0.0001(±2 × 10⁻⁵) MSD) e^0.089T, respectively, where MSD corresponds to the maximum shell diameter of the individual.     

Industrial accidents triggered by earthquakes,floods and lightning: lessons learned from a database analysis

Natural hazards and disasters can cause major accidents in chemical and process installations. These so-called Natech accidents can result in hazardous-materials releases due to damage to process and storage units, or pipes. In order to understand the dynamics of Natech events, accidents triggered by earthquakes, floods and lightning recorded in industrial accident databases were analysed. This allowed the identification of the most vulnerable equipment types, their modes of failure due to natural-event impact and the final accident scenarios. Moreover, lessons learned for future accident prevention and mitigation were derived. The analysis showed that pipes and storage tanks are the most vulnerable equipment for earthquakes, floods and lightning, calling for more research of equipment behaviour under natural-event loading. The damage modes and states are strongly dependent on the characteristics of the impacting natural event. Toxic dispersion, fires and explosions were observed as a consequence of all three types of analysed natural events. In the case of floods, two additional scenarios were identified. These are water contamination and the formation of toxic and/or flammable vapours upon reaction of the released chemicals with the floodwaters. The overall number of recorded Natech accidents was found to range from 2 to 5% of all reported accidents in the analysed databases.     

Combined object-based classification and manual interpretation–synergies for a quantitative assessment of parcels and biotopes

Recent technical advances in remote sensing data capture and spatial resolution lead to a widening gap between increasing data availability on the one hand and insufficient methodology for semi-automated image data processing and interpretation on the other hand. At the interface of GIS and remote sensing, object-based image analysis methodologies are one possible approach to close this gap. With this, methods from either side are integrated to use both the capabilities of information extraction from image data and the power to perform spatial analysis on derived polygon data. However, dealing with image objects from various sources and in different scales implies combining data with inconsistent boundaries. A landscape interpretation support tool (LIST) is introduced which seeks to investigate and quantify spatial relationships among image objects stemming from different sources by using the concept of spatial coincidence. Moreover, considering different categories of object fate, LIST enables a change categorization for each polygon of a time series of classifications. The application of LIST is illustrated by two case-studies, using Landsat TM and ETM as well as CIR aerial photographs: the first showing how the tool is used to perform object quantification and change analysis; the latter demonstrating how superior aggregation capabilities of the human brain can be combined with the fine spatial segmentation and classification. Possible fields of application are identified and limitations of the approach are discussed.