Guano-derived δ13C-based paleo-hydroclimate record from Gaura cu Musca Cave,SW Romania

The δ¹³C values of 23 unevenly spaced guano samples from a 17-cm long clay sediment profile in Gaura cu Musc? Cave (GM), in SW Romania, made it possible to preliminarily characterize the Medieval Warm Period summer hydroclimate regime. The beginning of the sequence (AD 990) was rather wet for more than a century, before becoming progressively drier. After a brief, yet distinct wet period around AD 1170, drier conditions, with a possible shift from C₃ to a mixed C₃-dominated/C₄ type vegetation (2 ‰ lower δ¹³C values), prevailed for almost half a century before the climate became colder and wetter at the onset of the Little Ice Age, when bats left the cave. The guano-inferred wet and dry intervals from the GM Cave are mirrored by changes in the color and amount of clay accumulated in the cave. They also agree well with reconstructions based on pollen and charcoal from peat bogs and δ¹³C and δ¹⁸O on speleothems from other Romanian sites. Overall, these results indicate that the δ¹³C of bat guano can provide a sensitive record of the short-term coupling between local/regional climate and the plant–insect–bat–guano system.     

Tracking UVCS/SOHO Responsivity with Observations of <Emphasis Type="Italic">ζ</Emphasis> Tau

We have tracked the spectral responsivity of the ultraviolet channels of the UVCS (Ultraviolet Coronagraph Spectrometer) instrument on SOHO by repeated observations of a stable hot star. We demonstrate first that the ultraviolet spectral irradiance of the Be star ζ Tau (HD 37202) for the 100- to 125-nm wavelength range has been sufficiently constant for our purposes when measured periodically over the course of the SOHO mission. We then use ζ Tau as a radiometric transfer standard to determine an average decrease beginning in November of 1998 of 13.0% per year in the responsivity of the UVCS O vi channel for wavelengths near H i Ly α and for a particular UVCS unvignetted aperture used for science observations. The calibration tracking method involves separating two ζ Tau spectral regions that are overlapped on part of the detector. The change in the responsivity of UVCS/SOHO began in late 1998 as determined by comparison of simultaneous observations of the corona carried out with UVCS/SOHO and the freshly-calibrated UVCS instrument on the Spartan 201 satellite in early November of 1998. B. Valcu now at BrainLAB, Inc, 3 Westbrook Corporate Ctr., Tower 3, Suite 400, Westchester, IL 60154, USA, e-mail: bogdan.valcu@brainlab.com or Bogdan_valcu@hotmail.com     

Poisson Recoding Of Solar Images For Enhanced Compression

The amount of useful scientific data that a space-borne telescope produces is often limited by the available telemetry of the platform. General purpose image compression schemes are usually used to compress the image either lossy or losslessly. These schemes do not take into account the fact that pixel values of typical solar images are only known to within a certain uncertainty range. We present a preprocessing method to enhance the performance (compression ratio) of any subsequent image compression scheme. The method uses estimates of the photon shot and thermal noises to compute a recoding look-up table that maps the initial data into uncertainty intervals. The recoding method is lossy in a mathematical sense but lossless in a physical sense, since the image alterations are guaranteed to be smaller than the Poisson noise. The performance of any further compression algorithm is enhanced while achieving a known guaranteed maximum absolute error for each pixel in the case of lossless compression. This revised version was published online in October 2005 with corrections to one of the authors' names.     

Geohazards assessment and mapping of some Balkan countries

The assessment of geological hazard is a topic with significant interest for the Balkans. During the last decade of twentieth century, most of the countries in the region have embarked on the road of a hasty transitory period from totalitarian regimes to democracy. Development of free market economy has given rise to uncontrolled movement of people, fast construction of housing and facilities and unproportioned accumulation of population around and in big cities. Besides Greece, an old member of European Union, and two newcomers in the organization, Romania and Bulgaria, the other countries are all hoping to enter the Union as faster as they can. Many different candidate or full-fledged member country programs of European Community offer a lot of joint and cross-border projects for constructing road infrastructure and facilities. As development accelerates in the Balkans and given the intensive geohazard elements that this territory exhibits, it becomes increasingly important to understand, study, and map these elements for being aware of the damage to the total environment these hazards might cause. The geohazard map and assessment of some Balkan countries has been carried out through two scientific meetings in Ohrid, Macedonia, and Tirana, Albania during 2007. The map is compiled in the Albanian Geological Survey, Tirana, Albania in the scale 1:1,000,000. As a base map, we used the topographic map produced by VGI, formerly Yugoslavia mapping authorities. As a seismic layer in our map, we used the values of peak ground acceleration obtained from Global Seismic Hazard Assessment Program. Two catalogs were constructed: The first one that contains the crustal earthquakes (hypocentral depth within first 70?km) and the second one that contains intermediate earthquakes (hypocentral depth below 70?km). This work is largely based on previous studies and investigations by earth scientists and specialists of each country comprised in this territory. In this respect, the map we constructed should be considered as a preliminary composite geohazard map with the possibility to be enriched and added with other new elements and data in the future.     

Toponymy and the Communist city: Street names in Bucharest, 1948–;1965

Past studies of the Socialist/Communist city have paid only limited attention to the ways in which Communist regimes mobilised a wide variety of symbols in the urban landscape in order to legitimate and institutionalise the ideology of revolutionary socialism. This paper considers the role of street names in this process with particular reference to Bucharest, Romania during the 1948–1965 period. When the Communist regime came to power it embarked on widespread renaming of streets as one means of both `decommemorating' the pre-socialist regime and proclaiming the agenda and ideology of the Communist state. The new street names commemorated a variety of events and personalities from the history of Romanian and Soviet Communism. The impact of street names was amplified further through practices such as multiple namings and the spatial clustering of street names of high ideological resonances. The paper argues that Bucharest's street names can be `read' as a mirror of ideological change, changing constructions of national identity, and Romania's macro-political orientation (especially its changing relations with the Soviet Union).     

Groundwater study of a volcanic area near Bandung,Java, Indonesia

A hydrogeological investigation of the Bandung area, Java, Indonesia, is described. The investigation was carried out as part of a feasibility study directed towards improvement and development of the city's water supply.The area is situated in a tropic mountainous region, dominated by pyroclastic volcanic deposits and with abundant rainfall. The main activities of the investigation were compilation and evaluation of existing climatological and hydrogeological data, testing of four existing wells, a geo-electrical survey, drilling and testing of a new test well, study of water quality by analysis of samples from both springs and wells, and measurements of spring yields.The results of the investigation indicated presence of large groundwater resources within a distance of 15–20 km from the city. The feasibility study recommended that Bandung's water supply be based on these groundwater resources and this recommendation is being implemented.During the investigation some results concerning rainfall, infiltration, aquifers, geoelectrical surveying, and groundwater quality were obtained, which may be of general interest for hydrologists and geologists working in tropical volcanic and mountainous regions. These results are summarized in the conclusion of this paper.     

Chechnia: The Empire strikes back

The war in Chechnia has few purely military targets and virtually no safe quarters for the population of the republic. The full scale of environmental devastation caused by the Russian invasion of Chechnia will probably be never properly quantified. Reports by independents paint a picture of an immense destruction of the country by the invading Russian army including whole towns and villages. In Chechnia Russia has been up against a national war of liberation and not as the Russian political and military establishment claims a few illegal armed bandits. The social structure of the Chechen society reinforces the long history of Chechen resistance to continuous attempts to subjugate the Chechen people and their integration into Russian political and economic structures.The current tragedy of Chechnia, the latest in series since the incorporation of the Caucasus into the Tsarist Empire, is to a large extend due to thematrioshka effect and the inability of the current Russian authorities to develop a viable nationality policy which would allow genuine devolution of power to the constituent parts of the Russian Federation. The dominant view of the current Russian leadership is that the constitutional principle of preserving the state on its historical and geo-political basis overrides the right of ethnic people to their own clearly defined sovereign political and economic entities. To many Russian and outside observers the Russian Federation appears to be a corpse without a head. Unless Russia's policy changes substantially there must be substantial doubts whether the Federation can survive in its present form. The prolonged guerilla war which is bound to follow the December 1994 invasion of Chechnia, rather than preserving the integrity of the Russian Federation would surely add to its progressive disintegration.     

Bridging Deep Convolutional Autoencoders and Ensemble Smoothers for Improved Estimation of Channelized Reservoirs

Mathematical Geosciences - One of the main problems associated with applying data assimilation methods for facies models is the lack of geological plausibility in updates. This issue is even more...     

Comparative review of data-driven landslide susceptibility models: case study in the Eastern Andes mountain range of Colombia

Natural Hazards - Estimating the likelihood of landslides has proven to be critical for development and protection of infrastructure (e.g. pipelines, roads) and urban settlements. Currently, for...