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Full-Text Articles in Earth Sciences

Comparative Estimate Of Resistance To Drought For Selected Karstic Aquifers In Bulgaria, Tatiana Orehova Jan 2004

Comparative Estimate Of Resistance To Drought For Selected Karstic Aquifers In Bulgaria, Tatiana Orehova

International Journal of Speleology

Effective management of water resources requires adequate knowledge of groundwater system including the influence of climate variability and climate change. The drought of 1982-1994 in Bulgaria has led to important decrease of springflow and lowering of water levels. Therefore, groundwater demonstrated its vulnerability to drought. The purpose of this paper is to determine relative resistance of selected aquifers in Bulgaria to a prolonged decrease of recharge to groundwater. The drought resistance indicator has been defined for some karstic aquifers based on the method proposed in report of BRGM. The data from National Hydrogeological Network located in the National Institute of …


Surface Cover Infiltration Index: A Suggested Method To Assess Infiltration Capacity For Intrinsic Vulnerability In Karstic Areas In Absence Of Quantitative Data, Levent Tezcan, Mehmet Ekmekci Jan 2004

Surface Cover Infiltration Index: A Suggested Method To Assess Infiltration Capacity For Intrinsic Vulnerability In Karstic Areas In Absence Of Quantitative Data, Levent Tezcan, Mehmet Ekmekci

International Journal of Speleology

Karst is a hydrogeological environment of importance not only for its water resources potential but also for its scenic and economic potential, thereby increasing the intensity of human impact. The uniqueness of karst in this regard stems from its high sensitivity and vulnerability to imposed pressures and its distinctive response to these pressures. Therefore, a clear definition and formulation of the concept of ‘intrinsic vulnerability’ is essential for the design of vulnerability and/or management criteria of the karstic system as a resource. In this regard, the recharge rate, the amount of water passing through the unsaturated zone into the aquifer, …


The Distribution Of Radon Concentration In Caves, Arrigo A. Cigna Jan 2004

The Distribution Of Radon Concentration In Caves, Arrigo A. Cigna

International Journal of Speleology

Radon concentration in caves is known to vary within an extremely wide range. Here the distribution of the average values of radon concentration is examined and a power law describing is identified, i.e. radon concentration has a fractal dimension D=1.26. This fact means that concentrations are not grouped around a mean value, a characteristic common to many other phenomena.


20 Years Of Speleothem Paleoluminescence Records Of Environmental Changes: An Overview, Yavor Y. Shopov Jan 2004

20 Years Of Speleothem Paleoluminescence Records Of Environmental Changes: An Overview, Yavor Y. Shopov

International Journal of Speleology

This paper discusses advance of the research on Speleothem Paleoluminescence Records of Environmental Changes after it have been first introduced by the author 20 years ago. It is demonstrated that most of the progress in this field was made in result of the operation of the International Program “Luminescence of Cave Minerals” of the commission on Physical Chemistry and Hydrogeology of Karst of UIS of UNESCO. Potential, resolution and limitations of high resolution luminescence speleothem proxy records of Paleotemperature, Solar Insolation, Solar Luminosity, Glaciations, Sea Level advances, Past Precipitation, Plants Populations, Paleosoils, Past Karst Denudation, Chemical Pollution, Geomagnetic field and …


Influence Of Solar Luminosity Over Geomagnetic And Climatic Cycles As Derived From Speleothems, Y. Shopov, D. Stoykova, L. Tsankov, M. Sanabria, D. Georgieva, D. Ford, L. Georgiev Jan 2004

Influence Of Solar Luminosity Over Geomagnetic And Climatic Cycles As Derived From Speleothems, Y. Shopov, D. Stoykova, L. Tsankov, M. Sanabria, D. Georgieva, D. Ford, L. Georgiev

International Journal of Speleology

We observed cycles presented in a luminescent solar insolation proxy record from a speleothem from Jewel Cave, South Dakota, US. We found cycles of orbital precession with periods of 23 and 19 ka and of obliquity of 41 ka and many others from non-orbital origin in this sample. We determined the Solar origin of the cycles with durations of 11500, 4400, 3950, 2770, 2500, 2090, 1960, 1670, 1460, 1280, 1195, 1145, 1034, 935, 835, 750 and 610 years. It was done by their detection both in proxy records of speleothem luminescence, Δ14C and the intensity of the geomagnetic …


Activators Of Luminescence In Speleothems As Source Of Major Mistakes In Interpretation Of Luminescent Paleoclimatic Records, Y. Y. Shopov Jan 2004

Activators Of Luminescence In Speleothems As Source Of Major Mistakes In Interpretation Of Luminescent Paleoclimatic Records, Y. Y. Shopov

International Journal of Speleology

This work summarizes the main results of the operation of the International Program “Luminescence of Cave Minerals” of the commission on Physical Chemistry and Hydrogeology of Karst of UIS of UNESCO in the field of activators of speleothem luminescence. It discusses Activators of Luminescence in Speleothems as a source of major mistakes in the interpretation of luminescent paleoclimatic records. It demonstrates the existence of 6 types of luminescence of speleothems and cave minerals in dependence of the type of the luminescence center and its incorporation in the mineral. 24 different activators of photoluminescence of speleothem calcite and 11 of aragonite …


Evolution Of Golpazari-Huyuk Karst System (Bilecik-Turkey): Indications Of Morpho-Tectonic Controls, Mehmet Ekmekci, Lütfü Nazik Jan 2004

Evolution Of Golpazari-Huyuk Karst System (Bilecik-Turkey): Indications Of Morpho-Tectonic Controls, Mehmet Ekmekci, Lütfü Nazik

International Journal of Speleology

The Golpazari-Huyuk karst system is located in the Central Sakarya Basin whose geomorphologic evolution is mainly controlled by the Post-Miocene epirogenic continental rise. Drastic change in the drainage pattern and dissection of the carbonate platform were the major consequences of this tectonic movement. Rapid incision of the Sakarya river changed the position of the erosion base which consequently distorted the direction of surface and subsurface flow. The Golpazari and Huyuk plains are two topographically distinct, flat bottomed geomorphic features separated by a carbonate rock relief. The difference in elevation between these 10 km distant plains is 350 m. Morphological, geological …


Dissaggregation Modelling Of Spring Discharges, Elena Kirilova Bojilova Jan 2004

Dissaggregation Modelling Of Spring Discharges, Elena Kirilova Bojilova

International Journal of Speleology

Disaggregation models are basically divided into three main groups: temporal, spatial and temporal-spatial. The focus of this paper is the application of temporal disaggregation models to disaggregate the seasonal flow in some large time intervals to sub-seasonal flows in some shorter time intervals. Two basic models are applied: the original model of Mejia and Rousselle and the corrected extended Lin model one-stage disaggregation. The flow totals from some karstic springs are used. Data for five springs in different areas of Bulgaria for the aims of the study are executed. The synthetic data generation for the chosen spring stations for a …


The Role Of The Environmental Archaeologist In The Study And Reconstruction Of Cave Palaeoclimate, Maria Gkioni Jan 2004

The Role Of The Environmental Archaeologist In The Study And Reconstruction Of Cave Palaeoclimate, Maria Gkioni

International Journal of Speleology

Man and environment are engaged in a continuous battle to impose themselves on one another. The results are found in environmental modifications or climatic oscillations and, as far as man is concerned, in the different character of cultural remains. Man responds to environmental changes by migrating or evolving technological innovations, both of which leave important remains that the archaeologist is called on to recognise and interpret during and after an excavation. They both also reflect the sociocultural responses to climatic stress. This paper refers to a specific case study, caves, which housed man and his activities from the very early …


Paleocollapse Structures As Geological Record For Reconstruction Of Past Karst Processes During The Upper Miocene Of Mallorca Island, P. A. Robledo Ardila, J. J. Durán, L. Pomar Jan 2004

Paleocollapse Structures As Geological Record For Reconstruction Of Past Karst Processes During The Upper Miocene Of Mallorca Island, P. A. Robledo Ardila, J. J. Durán, L. Pomar

International Journal of Speleology

Paleocollapse structures and collapse breccias are one of the major features for paleokarst analysis and paleoclimate record. These are affecting the Llucmajor and Santanyí carbonate platforms. These platforms, of southern and eastern Mallorca respectively, are a good example of progradation reef platform in the western Mediterranean. The Santanyí platform is constituted of two sedimentary units, both affected by paleocollapse structures: (1) The Reef Complex attributed to the upper Tortonian-lower Messinian; (2) Santanyí Limestone attributed to the Messinian. There are abundant paleocollapse outcropping in the Reef Complex and Santanyí Limestone units. These structures have been produced by roof collapse of caverns …


Trace Elements In Speleothems. A Short Review Of The State Of The Art, Sophie Verheyden Jan 2004

Trace Elements In Speleothems. A Short Review Of The State Of The Art, Sophie Verheyden

International Journal of Speleology

A state of the art of the research on trace elements of speleothems is given. First studies focussed on problems such as the colour of speleothems and the aragonite problem. Insitu studies and studies oriented towards a better understanding of vadose hydrology brought new insights in the controls on trace elemental composition of speleothems. Recent studies deal with microscale analyses and annual and intra-annual chemistry changes. Further in-situ studies should be performed to further differentiate influences, such as climate, soil/weathering and local hydrology in order to better constrain possible transfer functions between the surface and a speleothem.


Cave Temperatures And Global Climatic Change, Giovanni Badino Jan 2004

Cave Temperatures And Global Climatic Change, Giovanni Badino

International Journal of Speleology

The physical processes that establish the cave temperature are briefly discussed, showing that cave temperature is generally strictly connected with the external climate. The Global Climatic changes can then influence also the underground climate. It is shown that the mountain thermal inertia causes a delay between the two climates and then a thermal unbalance between the cave and the atmosphere. As a consequence there is a net energy flux from the atmosphere to the mountain, larger than the geothermal one, which is deposited mainly in the epidermal parts of caves.