MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

Community news

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 karst breccia is see collapse breccia; solution breccia.?

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

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
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;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for breakthrough (Keyword) returned 87 results for the whole karstbase:
Showing 76 to 87 of 87
Entrances, 2012, White, William B.

Entrances are connections between an underlying cave passage and the surface above. Most cave entrances are statistical accidents where the breakthrough to the surface is caused by collapse, by valley deepening, or by human activities such as road cuts, quarries, and other excavations. The number of caves with a certain number of entrances decreases rapidly with the number of entrances, leading to the prediction of a large number of caves that have no entrances. Entrances range in size over several orders of magnitude but there is no relationship between the size of the entrance and the size of the cave.


Speleogenesis, Telogenetic, 2012, Gabrovek, Franci

Speleogenesis refers to the processes by which caves are formed. Telogenetic speleogenesis is the formation of caves in compacted, fractured, soluble rocks such as limestone, dolomite, and gypsum by circulating meteoric water. The kinetics of the known chemical reactions can be used to construct models that describe cave development as a function of time and the chemical and geological properties of the system. The common cave patterns of branchworks and mazes can be accounted for by hydraulic gradients and recharge rates.


Water Tracing in Karst Aquifers, 2012, Jones, William K.

Water tracer tests are usually conducted to establish the hydrologic connections between two or more points. The tracer is an identifiable label or marker added to flowing water that establishes the links between the injection point of the tracer and the monitoring points where the tracer reappears. Fluorescent dyes are the most commonly used tracers in karst aquifers, but a wide range of substances has been used successfully. The experimental design of a tracer test may be qualitative to simply establish if a hydrologic connection exists between two points, or quantitative to measure the time-concentration series (breakthrough curve) generated by the recovery of the tracer. Water tracer tests usually work well in karst areas because of the fast groundwater flow rates and the prevalence of flow paths restricted to discrete conduits.


From soil to cave: Transport of trace metals by natural organic matter in karst dripwaters, 2012, Hartland A. , Fairchild I. J. , Lead J. R. , Borsato A. , Baker A. , Frisia S. , Baalousha M.

This paper aims to establish evidence for the widespread existence of metal binding and transport by natural organic matter (NOM) in karst dripwaters, the imprint of which in speleothems may have important climatic significance. We studied the concentration of trace metals and organic carbon (OC) in sequentially filtered dripwaters and soil leachates from three contrasting sites: Poole's Cavern (Derbyshire, UK), Lower Balls Green Mine (Gloucestershire, UK) and Grotta di Ernesto (Trentino, Italy). The size-distribution of metals in the three soils was highly similar, but distinct from that found in fractionated dripwaters: surface-reactive metals were concentrated in the coarse fraction (>100 nm) of soils, but in the fine colloidal (b100 nm) and nominally dissolved (b1 nm) fractions of dripwaters. The concentration of Cu, Ni and Co in dripwater samples across all sites were well correlated (R2=0.84 and 0.70, Cu vs. Ni, Cu vs. Co, respectively), indicating a common association. Furthermore, metal ratios (Cu:Ni, Cu:Co) were consistent with NICA-Donnan n1 humic binding affinity ratios for these metals, consistent with a competitive hierarchy of binding affinity (Cu>Ni>Co) for sites in colloidal or dissolved NOM. Large shifts in Cu:Ni in dripwaters coincided with high fluxes of particulate OC (following peak infiltration) and showed increased similarity to ratios in soils, diagnostic of qualitative changes in NOMsupply (i.e. fresh inputs of more aromatic/hydrophobic soil organic matter (SOM) with Cu outcompeting Ni for suitable binding sites). Results indicate that at high-flows (i.e. where fracture-fed flow dominates) particulates and colloids migrate at similar rates, whereas, in slow seepage-flow dripwaters, particulates (>1 μm) and small colloids (1–100 nm) decouple, resulting in two distinct modes of NOM–metal transport: high-flux and low-flux. At the hyperalkaline drip site PE1 (in Poole's Cavern), high-fluxes of metals (Cu, Ni, Zn, Ti, Mn, Fe) and particulate NOM occurred in rapid, short-lived pulses following peak infiltration events, whereas low-fluxes of metals (Co and V>Cu, Ni and Ti) and fluorescent NOM (b ca. 100 nm) were offset from infiltration events, probably because small organic colloids (1–100 nm) and solutes (b1 nm) were slower to migate through the porous matrix than particulates. These results demonstrate the widespread occurrence of both colloidal and particulate NOM–metal transport in cave dripwaters and the importance of karst hydrology in affecting the breakthrough times of different species. Constraints imposed by soil processes (colloid/particle release), direct contributions of metals and NOM from rainfall, and flow-routing (colloid/particle migration) are expected to determine the strength of correlations between NOM-transported metals in speleothems and climatic signals. Changes in trace metal ratios (e.g. Cu:Ni) in speleothems may encode information on NOMcomposition, potentially aiding in targeting of compound-specific investigations and for the assessment of changes in the quality of soil organic matter.


Solute transport in solution conduits exhibiting multi-peaked breakthrough curves, 2012, Field M. S. , Leij F. J.

Solute transport in karst aquifers is primarily constrained to solution conduits where transport is rapid, turbulent, and relatively unrestrictive. Breakthrough curves generated from tracer tests are typically positively-skewed and may exhibit multiple peaks. In order to understand the circumstances under which multi-peaked positively skewed breakthrough curves occur, physical experiments utilizing singleand multiple-flow channels were conducted. Experiments also included waterfalls, short-term solute detention in pools, and flow obstructions. Results demonstrated that breakthrough curve skewness nearly always occurs to some degree but is magnified as immobile-flow regions are encountered. Multi-peaked breakthrough curves occurred when flow in the main channel became partially occluded from blockage in the main channel that forced divergence of solute into auxiliary channels and when waterfalls and detention in pools occurred. Currently, multi-peaked breakthrough curves are fitted by a multi-dispersion model in which a series of curves generated by the advection–dispersion equation are fitted to each measured peak by superimposing the measured breakthrough curve to obtain a combined model fit with a consequent set of estimated velocities and dispersions. In this paper, a dual-advection dispersion equation with first-order mass transfer between conduits was derived. The dual-advection dispersion equation was then applied to the multi-peaked breakthrough curves obtained from the physical experiments in order to obtain some insight into the operative solute-transport processes through the acquisition of a consequent set of velocities, dispersions, and related parameters. Successful application of the dual-advection, dispersion equation to a tracer test that exhibited dual peaks for a karst aquifer known to consist of two connected but mostly separate conduits confirmed the appropriateness of using a multi-dispersion type model when conditions warrant.


Evolution of Intrastratal Karst and Caves in Gypsum, 2013, Klimchouk, A. B.

The term ‘intrastratal karst’ denotes a series of evolutionary karst types corresponding to successive stages of karst developmentin a soluble rock while it moves back to exposure after being buried by younger strata. The major boundaryconditions, the overall circulation pattern, and extrinsic factors and intrinsic mechanisms of karst development appear tochange considerably between the stages, resulting in characteristic styles of cave development and surface karst morphology,particularly distinct in case of gypsum karst.As gypsum is much more soluble than carbonates, it does not survive long in outcrops beyond arid areas. Wheregypsum is exposed to the surface with no substantial karstification formed during various stages of reburial, the developmentof epigene solution porosity in this rock is hindered due to the fast dissolution, being limited to flow paths in whichthe breakthrough conditions can be attained quickly. However, karst processes in gypsum develop extensively in intrastratalkarst settings, with inheritance from the deep-seated stage through the denuded one. Karstification may commence in anystage of intrastratal development, and during the next successive stage, the process, although in changed conditions, will beaffected significantly by the preformed solution porosity. Speleogenesis in deep-seated gypsum karst is exclusively hypogene.In subjacent karst, both hypogene and epigene speleogenesis may operate depending on the locally prevailing flowregime, but hypogene speleogenesis still dominates. In entrenched and denuded karst types, speleogenesis is overwhelminglyepigenic, but it is greatly facilitated by the presence of solution porosity inherited from the previous stages.Diverse and expressive karst landforms related to subsurface conduits evolve through different stages of the intrastratal karstdevelopment.The subsidence hazard in regions underlain by gypsum differs substantially between the karst types, so that one canobtain a kind of integrated general hazard assessment by classifying a given individual karst according to its evolution state.In general, various types of intrastratal karst, subjacent karst in particular, are the most potent in generating subsidence problems, whereas exposed karst types, particularly open karst, are the least prone to subsidence


Bench-scale models of dye breakthrough curves, 2013, Anger Cale T. , Alexander Jr. E. Calvin

Fluorescent dye tracer breakthrough curves (TBCs) obtained from quantitative traces in karst flow systems record multiple processes, including advection, dispersion, diffusion, mixing, adsorption, and chemical reaction. In this study, TBCs were recorded from small, bench-scale physical models in an attempt to isolate, understand, and quantify some of these processes under full-pipe flow conditions. Dye traces were conducted through a suite of geometries constructed out of Pyrex glass. These geometries consisted of (1) linear conduits, of varying length and diameter, (2) single and dual mixing chambers, and (3) a single chamber with an immobile region. Each glass system was connected to a constant flow apparatus. Dye was then injected with a syringe, allowed to flow through the system, and be naturally or artificially mixed in the process. Solute breakthrough was recorded in a scanning spectrofluorophotometer and the resulting TBC was analyzed. Independent variables examined in each of the three settings were discharge (Q) and dye concentration (Co). Artificial mixing rates (RM), induced by magnetic stirrers in settings (2) and (3), were also considered. Initial runs varied Q from 0.75 to 1.25 mL/s, with constant RM ranging from 0 to 360 revolutions per minute (rpm). Preliminary data yield realistic-looking breakthrough curves with steeply rising leading edges, a peak, and an asymmetric, exponential tail. Analysis of laboratory variables with respect to hydraulic parameters extracted from each TBC suggests that discharge and mixing rate alone can differentiate conduit complexity at the laboratory scale.

 


Comparison of discharge, chloride, temperature, uranine, dD, and suspended sediment responses from a multiple tracer test in karst, 2013, Luhmann A. J. , Covington M. D. , Alexander S. C. , Chai S. Y. , Schwartz B. F. , Groten J. T. , Alexander Jr. E. C.

A controlled recharge event with multiple tracers was conducted on August 30, 2010. A pool adjacent to a sinkhole was filled with approximately 13,000 L of water. The water was heated, and salt, deuterium oxide, and uranine were added. The pool was then emptied into the sinkhole, and data were collected at Freiheit Spring approximately 95 m north of the sinkhole to monitor changes in discharge, temperature, conductivity/chloride, dD, uranine, and suspended sediment. This combined trace demonstrated the feasibility and utility of conducting superimposed physical, chemical, and isotopic traces. Flow peaked first at the spring and was followed by a suspended sediment peak; then essentially identical uranine, chloride, and dD peaks; and finally a temperature peak. The initial increase in flow at the spring recorded the time at which the water reached a submerged conduit, sending a pressure pulse to the spring at the speed of sound. The initial increase in uranine, chloride, and dD at the spring recorded the arrival of the recharge water. The initial change in temperature and its peak occurred later than the same parameters in the uranine, chloride, and dD breakthrough curves. As water flowed along this flow path, water temperature interacted with the aquifer, producing a delayed, damped thermal peak at the spring. The combination of conservative and nonconservative tracers illustrates unique pressure, advective, and interactive processes.


HOW DO APERTURE SIZES IN LIMESTONE VARY FOR THE ONSETS OF TURBULENT FLOW AND FIRST-ORDER DISSOLUTION KINETICS?, 2013, Faulkner Trevor

 

It is commonly stated in the literature that the “breakthrough” point at the transition from slow high-order to fast firstorder dissolution kinetics in limestone occurs at an exit aperture of about one centimetre, and that this coincides with the transition from a wholly laminar flow to a turbulent flow. These relationships are approximately true for a range of conduit geometries in sub-horizontally bedded strata. However, the exit aperture for the onset of turbulence varies with the hydraulic gradient whereas the exit aperture for the onset of first-order kinetics varies with the hydraulic ratio, which is the hydraulic gradient divided by the path length. These transitions only occur at the same exit aperture for planar fissures and cylindrical tubes of lengths 290 m and 452 m. Breakthrough can occur before or after the onset of turbulence. Aperture sizes for breakthrough and turbulence can be over a metre for long and shallow conduits but sub millimetre for short and steep conduits. This paper analyses these relationships for many conduits in natural and artificial conditions and discusses their relevance to the multitude of possible karst situations, where hydraulic ratios can be considered over 17 orders of magnitude.


A laboratory study of tracer tomography, 2013, Brauchler R. , Bhm G. , Leven P. , Dietrich C. , Sauter M.

A tracer tomographic laboratory study was performed with consolidated fractured rock in three-dimensional space. The investigated fractured sandstone sample was characterized by significant matrix permeability. The laboratory transport experiments were conducted using gas-flow and gas-tracer transport techniques that enable the generation of various flow-field patterns via adjustable boundary conditions within a short experimental time period. In total, 72 gas-tracer (helium) tests were performed by systematically changing the injection and monitoring configuration after each test. For the inversion of the tracer breakthrough curves an inversion scheme was applied, based on the transformation of the governing transport equation into a form of the eikonal equation. The reliability of the inversion results was assessed with singular value decomposition of the trajectory density matrix. The applied inversion technique allowed for the three-dimensional reconstruction of the interstitial velocity with a high resolution. The three-dimensional interstitial velocity distribution shows clearly that the transport is dominated by the matrix while the fractures show no apparent influence on the transport responses.


Effects of sinuosity factor on hydrodynamic parameters estimation in karst systems: a dye tracer experiment from the Beyyayla Sinkhole (Eskişehir, Turkey), 2013, Aydin H. , Ekmekci M. , Soylu M. E.

The sinuosity factor (SF) is a critical value in karst systems in terms of estimating their hydrodynamic parameters including groundwater velocity, coefficient of dispersion, etc., through dye tracer experiments. SF has been used in a number of different dye tracer experiments in karstic systems to estimate a representative flow path. While knowing SF is crucially important in the estimation of hydrodynamic parameters, its calculation is associated with significant uncertainty due to the complexity of subsurface karstic features. And yet, only a few studies have discussed its uncertainties, which might lead some errors in estimation of hydrodynamic parameters from dye tracer experiment. In this study, dye tracer experiments were conducted in two consecutive years (2003 and 2004) representing low and high flow conditions in the Beyyayla sinkhole (Eskişehir, Turkey) where the flow path is well known. Uranine was used in experiments as a tracer and QTRACER computer program was used to determine the hydrodynamic properties of the Beyyayla karst system as well as to gain insights into the effects of SF from dye tracer experiments on estimated parameters. The results showed that the breakthrough curve follows a unimodal and a bimodal distribution in low and high flow conditions, respectively. These different distributions stem from the water transport mechanisms, where velocities were calculated as 58.2 and 93.6 m h−1 during low and high flow conditions observed in a spring emerging from the south side of the studied system. The results also show that the coefficient of dispersion, Reynolds number, and Peclet number increased and longitudinal dispersivity decreased with the higher flow rate. Furthermore, the estimated parameters did not vary with either the flow conditions or the tracer transit time, but they have shown some variations with SF. When SF was increased by 50 %, a change in these parameters was obtained in the range of 50–125 %.


Assessment of forward osmosis as a possible mitigation strategy for urine management during extended cave exploration, 2014, Borer C. H. , Stiles W. J. , Stevenson J. C. , . Cabanillas K. E

Extended expeditions into caves for the purpose of survey, exploration, and scientific studies pose unique challenges to cavers, but also create the potential for environmental degradation as a result of human activities. Human waste disposal can present particular challenges during extended trips underground. Urine may cause rapid microbe proliferation and substantial odor when deposited in areas that do not receive frequent flooding, but weight and bulk make it impractical to carry many days worth of urine to the surface. In this study, we evaluated the feasibility of a forward osmosis system to concentrate nitrogen-containing and carbon-containing compounds, which would allow for cleaner treated liquid to be deposited in the cave. The concentrated waste solution, with lower weight and volume than the raw urine, could then be removed from the cave. In our analysis of volume and chemical changes of a urine solution treated over the course of a week-long trial, we determined that the system, as tested, does reduce the weight and concentrate the chemical constituents in urine, allowing some chemical separation from the treated liquid. Unfortunately, the drawbacks of this system (chemical breakthrough, added weight of the system, and unknown ecological effects associated with substantial sodium chloride additions to the cave) outweigh the benefits. We do not recommend this forward osmosis system, as tested, as an effective mitigation strategy, although other treatment strategies may hold promise.


Results 76 to 87 of 87
You probably didn't submit anything to search for