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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 rill is 1. small solution groove on surface exposures of limestone; most common in arid or semiarid areas [10]. 2. small channel cut by flowing water in the floor, wall, or ceiling of a cave [20]. 3. the smallest category of stream in any terrane [20]. synonyms: (french.) traces de ruissellement; (german.) rinne, kerbe; (greek.) riakion; (italian.) solchi di ruscellamento; (spanish.) arroyuelo; (turkish.) kucuk dere, oluk, ark.?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

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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 fracture flow (Keyword) returned 8 results for the whole karstbase:
Parameter identification in double-continuum models applied to karst aquifers., 1997, Mohrlok U. , Kienie J. , Teutsch G.
One modelling approach which proved successful in describing the groundwater flow within karst terraines is based on the double-continuum concept. This concept was first introduced by Teutsch (1988) and subsequently used by Teutsch & Sauter (1991), Sauter (1992), Lang (1995), Mohrlok (1996) and others to describe the ambivalent characteristics of karst aquifers. However, the approach has the drawback that the double-continuum model parameters can be determined only through model calibration (inverse approach), i.e. so far the model parameters cannot be related directly to physical field measurements. Therefore, in order to develop a better understanding of the physical significance of hydraulic parameters within double-continuum systems, a detailed numerical modeling study was conducted. For this purpose a number of synthetic but realistic karst aquifer network geometries were generated and analysed. The response of the karst network to recharge events was simulated using a detailed discrete fracture flow model with the resulting head and spring flow variographs being subsequently assumed as field measurements. This 'measured' data was then used for the calibration of a double-continuum model and the resulting parameters were compared to the original karst network geometry data. This comparison was used to develop mathematical/physical relationships between the discrete karst network geometry representing reality and the double-continuum parameter representation of it.

Karstic groundwater flow characteristics in the Cretaceous Chalk aquifer, Northern Ireland, 1999, Barnes S,
The Cretaceous Chalk in Northern Ireland (Ulster White Limestone Formation) is a locally important aquifer for both public and private supply, yet little is known about its groundwater flow regime. This issue is important for the protection of existing groundwater abstractions and for the development of new sources as it will help determine groundwater vulnerability and resource potential in the Chalk. The subject has been addressed using hydrochemical variations from individual springs, together with artificial and natural water tracing techniques employed from river-sinks located at outcrop. A common orientation has been established between traced groundwater flow routes and the dominant northwest-southeast fracture trend within the Ulster White Limestone Formation. Hydraulic gradient has also been shown to have little significance in controlling the flow direction, suggesting poor fracture connectivity and thus extreme aquifer heterogeneity. Tracer breakthrough curve characteristics and velocities (up to 2838 metres per day) are indicative of conduit rather than fracture flow. In addition, the highly variable water chemistry associated with all the proven river-sink supplied springs has been independently classified to meet conduit flow criteria. Conversely, the much less variable water chemistry associated with springs draining Chalk subcrop areas (with no influence from river-sinks) is consistent with a less active karstic regime

Groundwater in the Celtic regions, 2000, Robins N. S. , Misstear B. D. R. ,
The Celtic regions of Britain and Ireland have a complex and diverse geology which supports a range of regionally and locally important bedrock aquifers and unconsolidated Quaternary aquifers. In bedrock, aquifer units are often small and groundwater flow paths short and largely reliant on fracture flow. Groundwater has fulfilled an important social role throughout history, and is now enjoying renewed interest. Groundwater quality is generally favourable and suitable for drinking with minimal treatment. However, many wells are vulnerable to microbiological and chemical pollutants from point sources such as farmyards and septic tank systems, and nitrate concentrations from diffuse agricultural sources are causing concern in certain areas. Contamination by rising minewaters in abandoned coalfields and in the vicinity of abandoned metal mines is also a problem in some of the Celtic lands

Numerical analysis of conduit evolution in karstic aquifers. PhD Thesis, 2003, Annable, W. K.

Fractured and solutionally enhanced carbonate aquifers supply approximately 20 percent of the Worlds potable water supply. Although in rare cases these geologic settings can geochemically evolve into conduits which are of sufficient size to be explored and interpreted by researchers, the majority of the solutionally enlarged networks providing fresh water supplies remain too small to be directly measured. As such, we rely upon indirect hydraulic testing and tracer studies to infer the complexity and size of such aquifers. Because solutionally enhanced (karstic) aquifers have multiple scales of porosity ranging from matrix flow, fracture flow and open channel conduit flow, they are particularly vulnerable to contamination due to the high rates of chemical transport. In this study, a numerical model which solves for the variably-saturated flow, chemically-reactive transport and sediment transport within fractured carbonate aquifers has been developed to investigate the evolution of proto conduits from discrete fractures towards the minimum limits of caves which can be explored. The model results suggest that, although potentiometric surfaces can be of assistance in forecasting the possible locations of proto conduits at depth, many conduits are never detected using conventional observation wells relying upon hydraulic head data. The model also demonstrates the strong dependence in the pattern of vertical jointing on how conduits may evolve: fractures oriented similar to the mean groundwater flow direction show conduits evolving along the vertical fracture orientation; however, vertical fractures that differ significantly from the mean groundwater flow direction have vastly more complex dissolution networks. The transport of fine-grained sediments within the fractures has been shown to reduce the rates of conduit development in all but the highest velocity regions, resulting in simplified conduit networks, but at accelerated dissolution rates. The fully-coupled advective-dispersive and reactive chemistry equations were employed strictly with equilibrium reactions to simulate calcite dissolution. This study further shows that higher order kinetics in the form of the kinetic trigger effect of White (1997) are not required if diffusion between the rock matrix and the fracture surfaces account for multi-component matrix diffusion effects between the evolving conduits and the carbonate rock matrix according to the diffusional characteristics of the fractured rock system at hand.


Ground water flux distribution between matrix, fractures, and conduits: constraints on modelling, 2005, White W. , White E.

Calculations are presented to show the relative contribution of the matrix, fracture, and conduit permeability to the overall flow of ground water through a karst aquifer. The conceptual model is a cross-section spanning the full width and thickness of the aquifer. A constant, but adjustable head is assumed. The rock matrix is characterized by an adjustable hydraulic conductivity. Varying proportions of fractures and conduits of adjustable fracture apertures and conduit diameters were the calculational parameters. Calculations used Darcy’s law for matrix flow, the cube law for fracture flow, and the Darcy-Weisbach equation for conduit flow. The results show a surprising dominance of fracture flow in the early stages of aquifer development. A focusing mechanism is needed to localize the flow into a relatively small number of conduits.


Ground water flux distribution between matrix, fractures, and conduits: constraints on modeling, 2005, White W. B. , White E. L.
Calculations are presented to show the relative contribution of the matrix, fracture, and conduit permeability to the overall flow of ground water through a karst aquifer. The conceptual model is a cross-section spanning the full width and thickness of the aquifer. A constant, but adjustable head is assumed. The rock matrix is characterized by an adjustable hydraulic conductivity. Varying proportions of fractures and conduits of adjustable fracture apertures and conduit diameters were the calculational parameters. Calculations used Darcys law for matrix flow, the cube law for fracture flow, and the Darcy-Weisbach equation for conduit flow. The results show a surprising dominance of fracture flow in the early stages of aquifer development. A focusing mechanism is needed to localize the flow into a relatively small number of conduits.

Cryogenic fracturing of calcite flowstone in caves: theoretical considerations and field observations in Kents Cavern, Devon, UK, 2012, Lundberg Joyce, Mcfarlane Donald A.

Several caves in Devon, England, have been noted for extensive cracking of substantial flowstone floors. Conjectural explanations have included earthquake damage, local shock damage from collapsing cave passages, hydraulic pressure, and cryogenic processes. Here we present a theoretical model to demonstrate that frost-heaving and fracture of flowstone floors that overlie wet sediments is both a feasible and likely consequence of unidirectional air flow or cold-air ponding in caves, and argue that this is the most likely mechanism for flowstone cracking in caves located in Pleistocene periglacial environments outside of tectonically active regions. Modeled parameters for a main passage in Kents Cavern, Devon, demonstrate that 1 to 6 months of -10 to -15° C air flow at very modest velocities will result in freezing of 1 to 3 m of saturated sediment fill. The resultant frost heave increases with passage width and depth of frozen sediments. In the most conservative estimate, freezing over one winter season of 2 m of sediment in a 6-m wide passage could fracture flowstone floors up to ~13 cm thick, rising to ~23 cm in a 12-m wide passage. Natural flaws in the flowstone increase the thickness that could be shattered. These numbers are quite consistent with the field evidence.


MODELING SPELEOGENESIS USING COMPUTATIONAL FLUID DYNAMICS: POTENTIAL APPLICATIONS TO HYPOGENE CAVES, 2014, Covington M. , Myre J.

Numerical models of speleogenesis typically simulate flow and dissolution within single fractures or networks of fractures. Such models employ fracture flow and pipe flow equations to determine flow rates and only consider average velocities within each fracture segment. Such approximations make large scale simulations of speleogenesis tractable. However, they do not allow simulation of the formation and evolution of micro- or meso-scale cave passage morphologies. Such morphologies are frequently studied within a field setting and utilized for the interpretation of the speleogenetic processes that formed the cave. One classic example is the formation of scallops in cave streams with turbulent flow. Scallops are used to interpret past flow velocities and directions. However, a recent analysis of the theory of limestone dissolution in turbulent flow conditions suggests a discrepancy between theory and reality concerning the formation of limestone scallops (Covington, in review). Similarly, the only attempt to numerically simulate flute formation in limestone found that the flute forms were not stable (Hammer et al., 2011). Motivated by these puzzles, we are developing a computational fluid dynamics (CFD) framework for the simulation of the evolution of dissolution morphologies.

While this project was initially conceived to better understand dissolution in turbulent flow, the tools being developed are particu­larly well-suited to examine a variety of other questions related to cave morphology on the micro- and meso-scales. There has been significant recent discussion about the interpretation of features that are diagnostic of hypogenic or transverse speleogenesis, such as the morphological suite of rising flow defined by Klimchouk (2007). Other authors have suggested that such forms can be found in a variety of settings where confined flow is not present (Mylroie and Mylroie, 2009; Palmer, 2011). We propose that simulation of such forms using a CFD speleogenesis code will allow a more complete understanding of the connections between process and form, because in such simulations the processes occurring are well-known, well-defined, and also can be adjusted within controlled numeri­cal experiments, where relevant parameters and boundary conditions are systematically varied.

The CFD framework we are developing is based on the Lattice Boltzman method (Chen and Doolen, 1998), which is a popular tech­nique for modeling the mechanics of complex fluids, including fluid mixtures, reactive transport, porous media flow, and complex and evolving domain geometries. With this framework it is straightforward to simulate many of the processes occurring in hypogene settings, including complex fluid flows, dissolution, solute and heat transport, and buoyancy-driven flow. Furthermore, this modeling framework allows these processes to be coupled so that their interactions and feedbacks can be explored. With the suite of capabili­ties provided by this framework, we can begin to numerically simulate the processes occurring in hypogene speleogenesis, including the driving mechanisms and the role of buoyancy-driven flow and its relationship with the morphological suite of rising flow. In the spirit of a workshop, this work is presented as in-progress, in the hopes that it will stimulate discussion on potential applications of the model being developed.


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