Surface Photometry of Proplyds in the Vicinity of θ1 Ori C

Results of studies of the surface-brightness distributions of a group of young stellar objects located within 16″ of the star θ₁ Ori C are presented. Isophotes around each proplyd are constructed using violet, red, and near-infrared images. No regularity in the sizes of the diametral cross sections of the proplyds in the various photometric bands is observed. The measured relative intensities are converted to absolute fluxes, and the absolute luminosities of the brightest parts of the disks and of the disk peripheries are estimated. The ratio of the semi-major to the semi-minor axes of the objects range from 1.5 to 2.5. The maximum lengths of the proplyd tails in various filters range from 300 to 700 AU. They become shorter with decreasing distance from the illuminating star, possibly due to enhanced dissipation of the disk, due to the growth in the role of photovaporization.

     

From global to local: Testing the potential of cross-scaling in global data sets

The present study investigates the potential of readily available and easily accessible global data sets to understand regional/local level interactions in wetland systems. The biogeographical zones of India were used a base-frame to select three sites. The study well fits the interests of National Wetland Committee of India to investigate and document fundamental information on wetland extent/distribution. The national partnership with SACON represents this interest. SACON commenced the inland wetland inventory module at national scale using geospatial data, although the provincial scale analysis is underway. In addition, the global irrigated area mapping (GIAM-IWMI) project generated multi-scalar spatial outputs for irrigated/rain-fed areas. With the existing information base, a multi-level geospatial analysis using Arc GIS algorithmic modelling was used to derive comprehensive appraisal of wetland systems complementing the data from GIAM and SACON. It was observed that the overlap between the two layers was 58 percent for Gujarat and 10 percent in Tamil Nadu. In Krishna basin the wetland’s cover 1.04 million hectare excluding the rice agro-ecosystem. The difference in the biogeography of the case sites governs the gradient of information derived from both data layers. Additionally, the global lakes and wetlands database (GLWD) database added thematic information on coastal wetlands. In summary we describe the cross-scaling the global data layers to compliment the regional/national level monitoring assignments.     

Specific features of ice conditions in the Sea of Azov and the Kerch Strait in the winter season of 2005/06

Peculiarities of the ice situation in the Sea of Azov and the Kerch Strait during the cold winter of 2005/06 are considered using a set of satellite images in the visible range, accumulated at the Southern Research Institute of Marine Fisheries and Oceanography (in Kerch). The ice conditions of the water area over the last years are examined and compared to the climatic data.     

The effect that coarse particles have on estimates of both optical and radiation characteristics of dust aerosol

Based on mathematical simulation, quantitative estimates of the effect that coarse dust particles have on the accuracy of retrieving the optical characteristics of aerosol have been obtained from the results of ground-based measurements of the spectral fluxes of both direct and scattered solar radiations. The results of verifying a retrieval algorithm (used at the AERONET ground-based network) based on special test models showed that the aerosol characteristics retrieved with this algorithm are unsuitable for calculating integral solar fluxes and for simulating space spectrometric IR measurements when the concentration of dust particles in the atmosphere exceeds their concentration in the well-known CONT model of continental aerosol by a factor of two or more.     

A note on the useable dynamic range of accelerographs recording translation

Since the late 1970s, the dynamic range and resolution of strong motion digital recorders have leaped from 65 to 135 dB, opening new possibilities for advanced data processing and interpretation. One of these new possibilities is the calculation of permanent displacement of the ground or of structures, associated with faulting or with non-linear response. Proposals on how permanent displacements could be recovered from recorded strong motion have been published since 1976. The analysis in this paper concludes that permanent displacements of the ground and of structures in the near-field can be calculated provided all six components of strong motion (three translations and three rotations) have been recorded, and the records are corrected for transducer rotation, misalignment and cross-axis sensitivity.     

Arumberia-type structures in the Upper Vendian of the Urals

Problematic arumberia-type structures are widespread in Upper Proterozoic sedimentary rocks deposited in depositional environments subject to periodic desiccation and fluctuating salinity. Here we report two new occurrences of arumberia-type structures in the Krutikha Member of the Upper Vendian Chernyi Kamen Formation on the western slope of the Central Urals (Us??va River) and the Zigan Formation of the Asha Group in the South Urals (new road Sterlitamak-Beloretsk). The results of the study of these structures significantly expand paleontological characteristics of the Upper Vendian non-marine rocks and allow us to re-examine the paleontological importance of the hastily forgotten group of arumberia-type organisms. We distinguished six varieties of arumberia-type structures that for the sake of convenience were given formal Latin names in binominal nomenclature although they are not biological species. Two species??Arumberia banski and A. vindhyanensis??were erected by previous researchers, whereas the A. beckeri, A. ollii, A. usvaensis, and A. multykensis varieties are recognized for the first time. Despite similarity to erosional structures on the bottom of turbidite beds, erosion does not explain the genesis of the entire spectrum of arumberia-type structures including those preserved on ripple marks, with evidence of soft-body deformation, or with ribbon and filamentous fabric replaced by clay minerals. The diversity of arumberia could be only a manifestation of living systems. The species of Arumberia are distinguished by their different biostratinomy, the distance between the main structural units, the preservation of the main structural units, and the presence of additional structures between the main structural units. Most likely, the diversity of arumberia reflects not only taphonomic, but also ontogenetic and phenotypic variation. The level of morphological complexity and biostratinomic features of arumberia apparently exceed the organization of microbial mats and represent a non-actualistic type of microbial communities. The occurrence in extremely shallow-water depositional setting suggests that arumberia had evolved an adaption to periodic desiccation and that arumberia-type organisms, along with microbial mats, had been an important factor of sediment biostabilization in the Late Vendian non-marine environments.     

Stress amplification in the upper crust and the development of normal faulting

Finite element analysis of lithosphere deformation, incorporating failure criteria based on the Modified Griffith Theory for an elastic upper crust and a visco-elastic rheology for the lower crust and lithospheric mantle, demonstrates that normal faulting as a result of comparatively small, horizontal tensile stresses acting throughout the lithosphere can occur by the phenomenon of stress amplification. The use of a simple, Newtonian viscosity or of power law creep for the visco-elastic material does not significantly change the results. The time to failure is dependent upon the magnitude of the applied stress and the effective viscosity of the underlying material. For an applied stress of 20 MPa and a constant viscosity of 10²³ Pa s failure is predicted after 1.19 Ma, with a fault plane hade of about 30°. A decrease of one order of magnitude in the viscosity of the lower crust results in a slightly shorter time to failure whereas an increase of one order of magnitude results in a very much greater failure time.     

What about reservoirs? Questioning anthropogenic and climatic interferences on water availability

Water resources in semi-arid regions like the Mediterranean Basin are highly vulnerable because of the high variability of weather systems. Additionally, climate change is altering the timing and pattern of water availability in a region where growing populations are placing extra demands on water supplies. Importantly, how reservoirs and dams have an influence on the amount of water resources available is poorly quantified. Therefore, we examine the impact of reservoirs on water resources together with the impact of climate change in a semi-arid Mediterranean catchment. We simulated the Susurluk basin (23.779-km²) using the Soil and Water Assessment Tool (SWAT) model. We generate results for with (RSV) and without reservoirs (WRSV) scenarios. We run simulations for current and future conditions using dynamically downscaled outputs of the MPI-ESM-MR general circulation model under two greenhouse gas relative concentration pathways (RCPs) in order to reveal the coupled effect of reservoir and climate impacts. Water resources were then converted to their usages – blue water (water in aquifers and rivers), green water storage (water in the soil) and green water flow (water losses by evaporation and transpiration). The results demonstrate that all water resources except green water flow are projected to decrease under all RCPs compared to the reference period, both long-term and at seasonal scales. However, while water scarcity is expected in the future, reservoir storage is shown to be adequate to overcome this problem. Nevertheless, reservoirs reduce the availability of water, particularly in soil moisture stores, which increases the potential for drought by reducing streamflow. Furthermore, reservoirs cause water losses through evaporation from their open surfaces. We conclude that pressures to protect society from economic damage by building reservoirs have a strong impact on the fluxes of watersheds. This is additional to the effect of climate change on water resources.     

Palaeomagnetism of (late Vendian-earliest Cambrian) minor alkaline intrusions, Fen Complex, southeast Norway

Emplacement of the Fen central complex (603-565 Ma) within the Fennoscandian Shield in southeast Norway was preceded by the emplacement of numerous minor alkaline intrusions into the surrounding gneisses. A palaeomagnetic sample of 28 of these bodies has identified a predominant SSE negative remanence carried by magnetite in some bodies and hematite in others. A sporadic high blocking temperature component appears to record localised effects associated with the development of the Oslo rift and igneous province to the east, but no major magnetic overprinting by post-emplacement events is recognised. The stable magnetisation vectors for twenty sites comprise a coherent population with those for two sites reversed with respect to the remainder; they yield a mean direction ofD = 210°,I = 44° (₉₅ = 6.4°) and a palaeomagnetic pole at 324°E, 50°S (dpdm=4.9°7.9°). The difference between the pole position for this early phase of the Fen magmatism and that for the late metasomatic rødberg (322°E, 63°S) in the interior of the complex is interpreted in terms of continental movement during the late Vendian-earliest Cambrian interval of alkaline activity here. The defined direction of APW movement continues a motion recognised from other Vendian data but subsequent movements during Lower Cambrian times are unclear.