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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That katavothron is (greek.) a closed depression or swallow hole [10].?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for coastal aquifers (Keyword) returned 11 results for the whole karstbase:
Chemical hydrogeology in natural and contaminated environments, 1989, Back W, Baedecker Mj,
Chemical hydrogeology, including organic and inorganic aspects, has contributed to an increased understanding of groundwater flow systems, geologic processes, and stressed environments. Most of the basic principles of inorganic-chemical hydrogeology were first established by investigations of organic-free, regional-scale systems for which simplifying assumptions could be made. The problems of groundwater contamination are causing a shift of emphasis to microscale systems that are dominated by organic-chemical reactions and that are providing an impetus for the study of naturally occurring and manmade organic material. Along with the decrease in scale, physical and chemical heterogeneity become major controls.Current investigations and those selected from the literature demonstrate that heterogeneity increases in importance as the study site decreases from regional-scale to macroscale to microscale. Increased understanding of regional-scale flow systems is demonstrated by selection of investigations of carbonate and volcanic aquifers to show how application of present-day concepts and techniques can identify controlling chemical reactions and determine their rates; identify groundwater flow paths and determine flow velocity; and determine aquifer characteristics. The role of chemical hydrogeology in understanding geologic processes of macroscale systems is exemplified by selection of investigations in coastal aquifers. Phenomena associated with the mixing zone generated by encroaching sea water include an increase in heterogeneity of permeability, diagenesis of minerals, and formation of geomorphic features, such as caves, lagoons, and bays. Ore deposits of manganese and uranium, along with a simulation model of ore-forming fluids, demonstrate the influence of heterogeneity and of organic compounds on geochemical reactions associated with genesis of mineral deposits. In microscale environments, importance of heterogeneity and consequences of organic reactions in determining the distributions and concentrations cf. constituents are provided by several studies, including infiltration of sewage effluent and migration of creosote in coastal plain aquifers. These studies show that heterogeneity and the dominance of organically controlled reactions greatly increase the complexity of investigations

Pollution by seawater intrusion into a karst system: new research in the case of the Almyros source (Heraklio, Crete, Greece), 2000, Arfib Bruno, De Marsily Ghislain, Ganoulis Jacques

Saline intrusion in karstic coastal aquifers is a common phenomenon which affects the quantity and quality of the freshwater resource. This paper examines the case of the Almyros system at Heraklio in Crete (Greece), characterized by a vast recharge area (300 km2) and a single brackish spring. Data from the Almyros spring and the surrounding wells are analyzed and a specific configuration of the karstic system is proposed. The evolution in time and space of the water temperature and chloride content is shown to be conditioned by the complex structure of this system and the heterogeneity of the karstic formations. These two parameters are analyzed and two storage zones are identified which generate different types of saline pollution. The water in the Almyros spring is not directly connected to the surrounding water-table aquifer. An inland reservoir far from the coast stores the cold, freshwater recharged in the mountains and supplies the Almyros spring. The pollution occurs during the transfer of the water toward the spring, through karstic conduits. Moreover, the local coastal aquifer is polluted by a generalized saline intrusion into the fractured matrix of the limestone, increased by withdrawals. Furthermore, the wells are contaminated by preferential saltwater flow through karstic channels reaching the seawater intrusion zone. The case of the Almyros system shows: (a) that a karstic coastal spring is not necessarily indicative of saline intrusion into the system; (b) that in optimal groundwater resource management, the whole hydrogeological system should be taken into account.

Palaeowaters in European coastal aquifers -- the goals and main conclusions of the PALAEAUX project, 2001, Edmunds Wm,
The PALAEAUX project has brought together up-to-date geochemical, isotopic and hydrogeological information on coastal groundwaters across Europe in a transect from the Baltic to the Canary Islands. These data have been interpreted in relation to past climatic and environmental conditions, as well as extending and challenging concepts about the evolution of groundwater near the present day coastlines. Groundwater movement beyond the present coastline as well as emplacement on shore to greater depths (up to 500 m) than allowed by the present-day flow regime has occurred, hence offshore freshwater reserves are inferred in some coastal areas. The main attributes of palaeowaters, in terms of water quality, are their high bacterial purity, total mineralization that is often less than that of modern waters and being demonstrably free of anthropogenic chemicals. However, in the Mediterranean coastal areas, lower recharge leads to higher salinity conditions in both palaeo- and modern waters. Freshwater of high quality originating from different climatic conditions to the present day, when the sea level was much lower, is found at depth beneath the present-day coastline in several countries. Recharge is shown to have been more or less continuous during the past 100 ka, even beneath the ice, as demonstrated by groundwaters from Estonia, having {delta}O values of c. -22%o. However, elsewhere (UK and Belgium) an age gap can be recognized indicating that no recharge took place at the time of the last glacial maximum. Devensian recharge temperatures (soil air temperatures) were some 6{degrees}C colder across Europe than at the present day. The development of aquifers in Europe during the past 50-100 a, by abstraction from boreholes, has generally disturbed flow systems that have evolved over varying geological timescales, especially those derived from the Late Pleistocene and Holocene. Hydrogeophysical logging has demonstrated time and quality stratified aquifers resulting in mixed waters being produced on pumping. A range of specific indicators, including 3H, 3H/3He, 85Kr, chlorofluoro-carbons and pollutants, have been used to recognize the extent to which waters from the modern (industrial) era have penetrated into the aquifers, often replacing the natural palaeogroundwaters. In the coastal regions, many problems for management are identified, including issues relating to quantity and quality of water, seasonal demand, pollution risks and ecosystem damage, requiring a new look at legislation

Recharge and aquifer response: Northern Guam Lens Aquifer, Guam, Mariana Islands, 2002, Jocson J. M. U. , Jenson J. W. , Contractor D. N. ,
The Northern Guam Lens Aquifer is an island karst aquifer in uplifted young, highly conductive limestone. Calculations of recharge based on differences between daily rainfall and daily pan evaporation suggest that the maximum annual mass of water delivered to the freshwater lens is about 67% of mean annual rainfall. Hydrographs of daily well-level responses plotted against daily rainfall indicate that the rate at which water is delivered to the lens is a function of rainfall intensity and the relative saturation of the vadose zone. Together, these variables determine the degree to which stormwater is shunted into fast flow through preferred pathways that bypass the bedrock matrix, rather than percolating slowly through the bedrock matrix. Data from the 40-year interval from 1956 to 1995 show that some 17% of rainfall on northern Guam arrives in small amounts (<0.6 cm/day). Most of this light rainfall is probably lost to evapotranspiration. At least another 20% of total rainfall on Guam arrives at very high intensities (>5.0 cm/day), which tend to promote fast flow at the expense of percolation. Rapid recovery of the water table from rapid recharge suggests that the lens either takes such recharge into storage very rapidly, discharges it rapidly without taking it into storage, or some combination of both. Significant vadose buffering of recharge to the lens is indicated by the fact that simulations assuming that the recharge from precipitation received in any given month is transmitted to the lens during the same month consistently over-predict observed peak mean monthly water levels and under-predict the minima. (C) 2002 Elsevier Science B.V. All rights reserved

Physical modelling of the seawater intrusion within a karst aquifer: the case of the Almyros of Heraklion (Crete), 2004, Arfib B, Ganoulis J,
Physical modelling of the seawater intrusion within a karst aquifer: the case of the Almyros of Heraklion (Crete). Coastal aquifers are subjected to natural seawater intrusion. Laboratory experiments were made to model the hydraulic conditions of saltwater inflow into a porous karstic conduit through which the freshwater flows. The conceptual model is based on the functioning scheme of the coastal karst system Almyros of Heraklion, Crete. The experiments show that seawater intrusion in a karst conduit can be diffuse, does not always lead to density separation of freshwater and seawater, and is not necessarily related to a conduit-network directly connected to the sea.

On 226Ra and 222Rn concentrations in the brackish waters of coastal aquifers: lab-investigations and confirmation in the carbonate aquifer of Brindisi (Italy), 2005, Spizzico M. , Sciannamblo D. ,

On Ra-226 and Rn-222 concentrations in the brackish waters of coastal aquifers: lab-investigations and confirmation in the carbonate aquifer of Brindisi (Italy), 2005, Spizzico M. , Sciannamblo D. ,
The ground waters circulating in the Apulian mesozoic carbonate aquifer, of coastal type, show high concentrations of Rn-222 everywhere. Considering their variation during the different phases of a hydrological year, such high concentration values can reach activity of 20 Bq/L, in the more internal zones of the aquifer. Moreover, it is often observed that, in correspondence of wells and springs nearest the coast, the concentrations of radioactive gas reach values greater than 400 Bq/L and vary considerably during the course of a day and with withdrawals. The research carried out over the last few years, has confirmed that Ra-226 and Rn-222 concentrations in the karst groundwater of Apulia, are mainly related to the occurrence of 'Terra Rossa' inside the aquifer and the capacity of these paleosols to fix the salts of Ra-226 coming from the dissolution of the calcareous and calcareous-dolomitic rocks. This paper shows the results of the analysis performed to define Rn-222 increase in the brackish waters that come in contact with carbonate rocks and 'terra rossa'. It also indicates the results of surveys performed in a coastal zone with well-known hydrogeological features. The controls performed during one hydrological year, have confirmed the relationships between the salt content of the ground waters and the enrichment of Rn-222 and have highlighted that the manner of increase of this radioisotope is related to cases of ionic exchange and adsorption regulated by the dynamics of marine intrusion

Seawater intrusion in complex geological environments, 2005, Abarca Cameo, Elena

Modelling seawater intrusion (SWI) has evolved from a tool for understanding to a water management need. Yet, it remains a challenge. Difficulties arise from the assessment of dispersion coefficients and the complexity of natural systems that results in complicated aquifer geometries and heterogeneity in the hydraulic parameters. Addressing such difficulties is the objective of this thesis. Specifically, factors that may affect the flow and transport in coastal aquifers and produce heterogeneous salinity distributions are studied.

First, a new paradigm for seawater intrusion is proposed since the current paradigm (the Henry problem) fails to properly reproduce observed SWI wedges. Mixing is represented by means of a velocity dependent dispersion tensor in the new proposed problem. Thereby, we denote it as "dispersive Henry problem". SWI is characterized in terms of the wedge penetration, width of the mixing zone and influx of seawater. We find that the width of the mixing zone depends basically on dispersion, with longitudinal and transverse dispersion controlling different parts of the mixing zone but displaying similar overall effects. The wedge penetration is mainly controlled by the horizontal permeability and by the geometric mean of the dispersivities. Transverse dispersivity and the geometric mean of the hydraulic conductivity are the leading parameters controlling the amount of salt that enters the aquifer.

Second, the effect of heterogeneity was studied by incorporating heterogeneity in the hydraulic permeability into the modified Henry problem. Results show that heterogeneity causes the toe to recede while increases both the width and slope of the mixing zone. The shape of the interface and the saltwater flux depends on the distribution of the permeability in each realization. However, the toe penetration and the width of the mixing zone do not show large fluctuations. Both variables are satisfactorily reproduced, in cases of moderate heterogeneity, by homogeneous media with equivalent permeability and either local or effective dispersivities.

Third, the effect of aquifer geometry in horizontally large confined aquifers was analyzed. Lateral slope turned out to be a critical factor. Lateral slopes in the seaside boundary of more than 3% cause the development of horizontal convection cells. The deepest zones act as preferential zones for seawater to enter the aquifer and preferential discharging zones are developed in the upwards lateral margins. A dimensionless number, Nby, has been defined to estimate the relative importance of this effect.

All these factors can be determinant to explain the evolution of salinity in aquifers such as the Main aquifer of the Llobregat delta. Finally, a management model of this aquifer is developed to optimally design corrective measures to restore the water quality of the aquifer. The application of two different optimization methodologies, a linear and a non-linear optimization method, allowed (1) to quantify the hydraulic efficiency of two potential corrective measures: two recharge ponds and a seawater intrusion barrier; (2) to determine the water necessary to be injected in each of these measures to restore the water quality of the aquifer while minimizing changes in the pumping regime and (3) to assess the sustainable pumping regime (with and without the implementation of additional measures) once the water quality has been restored. Shadow prices obtained from linear programming become a valuable tool to quantify the hydraulic efficiency of potential corrective measures to restore water quality in the aquifer

Time scales in the evolution of solution porosity in porous coastal carbonate aquifers by mixing corrosion in the saltwater-freshwater transition zone, 2007, Dreybrodt W. , Romanov D.

Dissolution of calcium carbonate in the saltwater-freshwater mixing zone of coastal carbonate aquifers up to now has been treated by coupling geochemical equilibrium codes to a reactive- transport model. The result is a complex nonlinear coupled set of differential transport-advection equations, which need high computational efforts. However, if dissolution rates of calcite are sufficiently fast, such that one can assume the solution to be in equilibrium with respect to calcite a highly simplified modelling approach can be used. To calculate initial changes of porosity in the rock matrix one only needs to solve the advection-transport equation for salinity s in the freshwater lens and its transition zone below the island. Current codes on density driven flow such as SEAWAT can be used. To obtain the dissolution capacity of the mixed saltwater-freshwater solutions the calcium equilibrium concentration ceq(s) is obtained as a function of salinity by PHREEQC-2. Initial porosity changes can then be calculated by a simple analytical expression of the gradient of the spatial distribution s(x, y) of salinity, the distribution of flow fluxes q(x,y) and the second derivative of the calcium equilibrium concentration ceq(s) with respect to salinity s. This modelling approach is employed to porosity evolution in homogeneous and heterogeneous carbonate islands and coastal aquifers. The geometrical patterns of porosity changes and the reasons of their origin will be discussed in detail. The results reveal initial changes of porosity in the order of several 10-6 per year. This places the time scale of cavern evolution to orders from several tens of thousands to a hundred thousand years.

Brackish springs in coastal aquifers and the role of calcite dissolution by mixing waters , 2007, Sanz Escud, Esteban

Brackish springs are relatively frequent phenomena in coastal carbonate formations and their existence has been extensively reported in Mediterranean coasts. In fact, more than 300 brackish springs have been identified only in the coast of the former Yugoslavia. They essentially consist of inland or submarine karst outlets discharging waters with flow-dependent salinity. The phenomenon is particularly surprising in inland springs, where high flow rates with significant salinities (presumablyBrackish springs are relatively frequent phenomena in coastal carbonate formations and their existence has been extensively reported in Mediterranean coasts. In fact, more than 300 brackish springs have been identified only in the coast of the former Yugoslavia. They essentially consist of inland or submarine karst outlets discharging waters with flow-dependent salinity. The phenomenon is particularly surprising in inland springs, where high flow rates with significant salinities (presumably

A method for the stochastic modeling of karstic systems accounting for geophysical data: an example of application in the region of Tulum, Yucatan Peninsula (Mexico), 2012, Vuilleumier C. , Borghi A. , Renard P. , Ottowitz D. , Schiller A. , Supper R. , Cornaton F.

The eastern coast of the Yucatan Peninsula, Mexico, contains one of the most developed karst systems in the world. This natural wonder is undergoing increasing pollution threat due to rapid economic development in the region of Tulum, together with a lack of wastewater treatment facilities. A preliminary numerical model has been developed to assess the vulnerability of the resource. Maps of explored caves have been completed using data from two airborne geophysical campaigns. These electromagnetic measurements allow for the mapping of unexplored karstic conduits. The completion of the network map is achieved through a stochastic pseudo-genetic karst simulator, previously developed but adapted as part of this study to account for the geophysical data. Together with the cave mapping by speleologists, the simulated networks are integrated into the finite-element flow-model mesh as pipe networks where turbulent flow is modeled. The calibration of the karstic network parameters (density, radius of the conduits) is conducted through a comparison with measured piezometric levels. Although the proposed model shows great uncertainty, it reproduces realistically the heterogeneous flow of the aquifer. Simulated velocities in conduits are greater than 1 cm s−1, suggesting that the reinjection of Tulum wastewater constitutes a pollution risk for the nearby ecosystems.

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