Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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 degradation is 1. geological action of wearing down a surface [16]. 2. the process of degrading water quality in an aquifer by the addition of contaminants, either naturally or artificially. 3. the process by which various chemicals are altered to form new chemicals; breakdown.?

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

What is Karstbase?



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.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
See all featured articles
Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
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
See all featured articles from other geoscience journals

Search in KarstBase

Your search for uncertainty (Keyword) returned 31 results for the whole karstbase:
Showing 16 to 30 of 31
The early Ordovician Majiagou reservoir of the Jingbian Field, northwest China: Karstic peritidal dolomite, 2004, Zhang W. H. ,
The Jingbian Field is located in the central part of the Ordos Basin in the west part of the North China Platform. It is the largest gas field discovery in China in the 1980's. The field is an example of production from a paleogeomorphic trap formed by karstification of Lower Ordovician peritidal dolomites. In terms of gas potential, the Majiagou Formation is the more important stratigraphic unit. It is composed of six members, the uppermost member (O(1)m(6)) has been largely removed by prolonged Caledonian karst erosion, leaving the underlying (O(1)m(5)) member to provide the main pay for the field. In spite of the 163 wells drilled the field presents many problems and uncertainties because of the poor seismic definition of the pay zones and the great reservoir heterogeneity of the karst system. Statistical data from more than 30 wells show a poor correlation between individual well-flow rates and thickness of the karstic zone or distance of wells, relative to a paleochannel. This suggests karstification is not the most important factor controlling productivity. The release of organic acids (during maturation of the source rock) and fracturing in response to Cretaceous tectonic event appear to be key factors responsible for the productivity of the Majiagou-5 (O(1)m(5)) reservoir in terms of modifying and enlarging the pore network. Carboniferous clays provide an effective updip seal through the infill of karst-breccia zones. High productivity is prominent along structural axes where karstic fractures, solution vugs and caverns are interconnected by vertical to sub-vertical fractures. On the basis of pore-type the Majiagou-5 Member reservoirs can be divided into four reservoir types, each allowing differentiation of reservoir quality through characteristic porosity-permeability ranges and capillary-pressure curves. Key aspects which affect the commerciality of the field are still uncertain but with recent test wells producing gas with water, considerations should focus on the mechanism of weak edge-water drive and the need to predict fracture zones

Current issues and uncertainties in the measurement and modelling of air-vegetation exchange and within-plant processing of POPs, 2004, Barber Jl, Thomas Go, Kerstiens G, Jones Kc,
Air-vegetation exchange of POPs is an important process controlling the entry of POPs into terrestrial food chains, and may also have a significant effect on the global movement of these compounds. Many factors affect the air-vegetation transfer including: the physicochemical properties of the compounds of interest; environmental factors such as temperature, wind speed, humidity and light conditions; and plant characteristics such as functional type, leaf surface area, cuticular structure, and leaf longevity. The purpose of this review is to quantify the effects these differences might have on air/plant exchange of POPs, and to point out the major gaps in the knowledge of this subject that require further research. Uptake mechanisms are complicated, with the role of each factor in controlling partitioning, fate and behaviour process still not fully understood. Consequently, current models of air-vegetation exchange do not incorporate variability in these factors, with the exception of temperature. These models instead rely on using average values for a number of environmental factors (e.g. plant lipid content, surface area), ignoring the large variations in these values. The available models suggest that boundary layer conductance is of key importance in the uptake of POPs, although large uncertainties in the cuticular pathway prevents confirmation of this with any degree of certainty, and experimental data seems to show plant-side resistance to be important. Models are usually based on the assumption that POP uptake occurs through the lipophilic cuticle which covers aerial surfaces of plants. However, some authors have recently attached greater importance to the stomatal route of entry into the leaf for gas phase compounds. There is a need for greater mechanistic understanding of air-plant exchange and the 'scaling' of factors affecting it. The review also suggests a number of key variables that researchers should measure in their experiments to allow comparisons to be made between studies in order to improve our understanding of what causes any differences in measured data between sites. (C) 2003 Elsevier Ltd. All rights reserved

Inversion strategy in crosshole radar tomography using information of data subsets, 2004, Becht A, Tronicke J, Appel E, Dietrich P,
Detecting discrete anomalies, such as cavities or tunnels, is an important application of crosshole radar tomography. However, crosshole tomographic inversion results are frequently ambiguous, showing smearing effects and inversion artifacts. These ambiguities lead to uncertainties in interpretation; hence, the size and position of anomalies can only be interpreted with limited accuracy and reliability. We present an inversion strategy for investigating discrete anomalies with crosshole radar tomography. In addition to the full traveltime data set, we use subsets of specified ray-angle intervals for tomographic inversion. By analyzing inversion results from different ray-angle intervals, a more accurate interpretation of anomalies is possible. The second step of our strategy is to develop a good inhomogeneous starting model from joint interpretation of the inversion results from different subsets. The third step is to invert the full data set using this new starting model and to evaluate the inversion results by analyzing the distributions of mean square traveltime residuals with respect to the ray angles. We use a synthetic model with two discrete anomalies located roughly at the same depth to demonstrate and evaluate our approach. This inversion strategy is also applied to a field data set collected to investigate karst cavities in limestone. From the inversion results of both examples, we show that horizontal smearing of anomalies can be reduced by eliminating near-horizontal rays. A good starting model can be obtained based on the joint interpretation of the inversion results of the different subsets; it leads to a high-resolution final image of the full data set

Calcite dissolution kinetics and solubility in Na-Ca-Mg-Cl brines of geologically relevant composition at 0.1 to 1 bar pCO2 and 25 to 80°C. Doctoral dissertation, Texas A&M University. , 2005, Gledhill, Dwight Kuehl

Sedimentary basins can contain close to 20% by volume pore fluids that are commonly classified as brines. These fluids can become undersaturated with respect to calcite as a result of processes such as migration, dispersive mixing, or anthropogenic injection of CO2. This study measured calcite solubility and dissolution rates in geologically relevant Na-Ca-Mg-Cl synthetic brines (35 to 200 g L-1 TDS). In brines < 50 g L-1 TDS, the EQPITZER calculated calcium carbonate ion activity product (IAP) at steady-state was in reasonable agreement (±10%) with the thermodynamic solubility constant for calcite (Kc). However, the IAP systematically exceeded Kc in more concentrated brines. The deviation was strongly correlated with calcium concentration and also was observed in magnesium-free solutions. This is interpreted as an uncertainty in the carbonate ion activity coefficient, and minor adjustment in stoichiometric association constants (K*M2+CO30) for the CaCO30 or MgCo30 ion pairs would correct for the error. The dissolution rate dependency on brine composition, pCO2 (0.1 to 1 bar), and temperature (25.0 to 82.5 °C) was modeled using the empirical rate equation ()nkRΩ−=1 where R is the rate, k and n are empirical fitting terms, and Ω the degree of disequilibrium with respect to calcite. When Ω was defined relative to an apparent kinetic solubility, n could be assumed first-order over the range of Ω investigated (Ω = 0.2 to 1.0). Rates increased with increasing pCO2 as did the sensitivity to brine concentration. At 0.1 bar, rates were nearly independent of concentration (k = 13.0 ±2.0 x 10-3 moles m-1 hr-1). However, at higher CO2 partial pressures rates became composition dependent and the rate constant, k, was shown to be a function of temperature, pCO2, ionic strength, and calcium and magnesium activity. The rate constant (k) can be estimated from a multiple regression (MR) model of the form k = B0 + B1(T) + B2(pCo2) + B4(aCa2+) + B5(aMg2+). A relatively high activation energy (Ea = 20 kJ mol-1) was measured, along with a stirring rate independence suggesting the dissolution is dominated by surface controlled processes at saturation states Ω > 0.2 in these calcium-rich brines. These findings offer important implications to reaction-transport models in carbonate-bearing saline reservoirs.

Millipede (Diplopoda) fauna of the Dark Cave (Gua Gelap), Batu Caves, Selangor, Malaysia: species composition and ecological observations., 2006, Moseley M.
Millipedes are conspicuous and abundant in the Dark Cave, but there are few published records and thus uncertainty about the species composition of the fauna. There is also doubt about the ecological status and ecology of the three species reported from the cave (Plusioglyphyiulus grandicollis, Ascetophacus macclurei and Orthomorpha fluminoris). This paper reports some new records and field and laboratory observations that clarify some of these points.

A gray system model for studying the response to climatic change: The Liulin karst springs, China, 2006, Hao Yonghong, Yeh Tian Chyi, Gao Zongqiang, Wang Yanrong, Zhao Ying,
SummaryGray system theory uses a black-gray-white color spectrum to describe a complex system whose characteristics are only partially known or known with uncertainty. In this study, we use gray system theory to investigate the relation between precipitation and spring flows in a karst region in China. The gray incidence analysis was applied to the Liulin Springs, Shanxi Province, China to analyze the time-lag between spring flow and precipitation. The results showed that the average groundwater residence time at Liulin Spings is about 4 years. The gray system GM(1,2) model was subsequently used as a predictive tool for spring discharge. It was found that model predictions are in agreement with observed data. This study also shows that the discharge of the Liulin Springs primarily responds to climate change; anthropogenic impacts are secondary. The continuous decline of water level in the karst aquifer and waning of spring discharges in semi-arid regions of China might be largely a response of the groundwater system to the decline in regional precipitation over the past two decades

Timing and dynamics of the last deglaciation from European and North African [delta]13C stalagmite profiles--comparison with Chinese and South Hemisphere stalagmites, 2006, Genty D, Blamart D, Ghaleb B, Plagnes V, Causse C, Bakalowicz M, Zouari K, Chkir N, Hellstrom J, Wainer K, Bourges F,
The last deglaciation and its climatic events, such as the Bolling-Allerod (BA) and the Younger-Dryas (YD), have been clearly recorded in the [delta]13C profiles of three stalagmites from caves from Southern France to Northern Tunisia. The three [delta]13C records, dated by thermal ionization mass spectrometric uranium-thorium method (TIMS), show great synchroneity and similarity in shape with the Chinese cave [delta]18O records and with the marine tropical records, leading to the hypothesis of an in-phase (between 15.5 and 16 ka ~0.5 ka) postglacial warming in the Northern Hemisphere, up to at least 45[deg]N. The BA transition appears more gradual in the speleothem records than in the Greenland records and the Allerod seems warmer than the Bolling, showing here close similarities with other marine and continental archives. A North-South gradient is observed in the BA trend: it cools in Greenland and warms in our speleothem records. Several climatic events are clearly recognizable: a cooler period at about 14 ka (Older Dryas (OD)); the Intra-Allerod Cold Period at about ~13.3 ka; the YD cooling onset between 12.7 and 12.90.3 ka. Similar to the BA, the YD displays a gradual climate amelioration just after its onset at 12.750.25 ka, up to the Preboreal, and is punctuated by a short climatic event at 12.15 ka. Even though the Southern Hemisphere stalagmite records seem to indicate that the postglacial warming started about ~3 ka1.8 ka earlier in New Zealand (~41 [deg]S), and about ~1 to ~2 ka earlier in South Africa (24.1 [deg]S), large age uncertainties, essentially due to slow growth rates, make the comparison still perilous. The overall [delta]13C speleothem record seems to follow a baseline temperature increase controlled by the increase in insolation and punctuated by cold events possibly due to the N-America freshwater lake discharges

Chronology and paleoenvironment of Marine Isotope Stage 3 from two high-elevation speleothems, Austrian Alps, 2006, Spotl Christoph, Mangini Augusto, Richards David A. ,
A new high-resolution stable isotope record from the alpine Kleegruben Cave (2165 m, Central Alps) is presented. This record largely duplicates a previously reported speleothem record from this site. High-precision U-series thermal ionization mass spectrometry dates constrain the growth history of this new sample (56-48 ka) to the Marine Isotope Stage (MIS) 3. Both stalagmites reveal highly similar variations in O isotopes that can be directly compared to O isotope variability associated with Dansgaard-Oeschger interstadials recorded in the Greenland ice cores (Greenland Interstadials, GIS). Based on the new record we refine our previous age assignments of the GIS during this time interval, i.e. GIS 15b at 55.7 ka, GIS 15a at 55.3 ka, onset (mid-point) of the prominent GIS 14 at 54.5 yr and onset of GIS 12 at ~48 ka. The overall uncertainties associated with these ages are 0.1-0.3 ka. The timing of these Dansgaard-Oeschger interstadials is within 0.2 ka of the newly proposed GRIP.SFCP04 timescale.The age data for both Kleegruben stalagmites demonstrate that liquid water was at least seasonally present in the shallow sub-surface allowing calcite precipitation to continue even during stadials of MIS 3. Given the present-day low temperature (.4 [deg]C) we propose that these unusual speleothems formed in a karst system overlain by a warm-based glacier

UPb geochronology of speleothems by MC-ICPMS, 2006, Woodheada Jon, Hellstroma John, Maasa Roland, Drysdaleb Russell, Zanchettac Giovanni, Devined Paul, Taylor Eve

Building upon the work of Richards et al. [1998. U–Pb dating of a speleothem of Quaternary age. Geochimica et Cosmochimica Acta 62, 3683–3688], we have developed a method for precise dating of speleothems beyond the range of the U–Th technique using the U–Pb decay scheme. By coupling low-blank sample preparation procedures and multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) analytical methodologies developed for low-level Pb-isotope analysis, we find that, under ideal circumstances (radiogenic speleothems with very low common Pb), U–Pb dating of speleothems is not only possible, but also produces excellent age resolution— often comparable to or better than U–Th studies. Corrections for initial isotopic disequilibrium are necessary and exert a strong control on the achievable age uncertainty. The technique will be of immediate benefit in extending speleothem-based climate proxy records beyond _500 ka and will also find other uses, such as the dating of associated sub-fossil remains, and providing constraints on rates of landscape evolution and neo-tectonic processes. Here we present initial results for speleothems from the Nullarbor Plain, Western Australia, and the Alpi Apuane, Italy. The Nullarbor samples provide important new constraints on the development of aridity in Australia during the late Tertiary/early Quaternary, while the Apuane samples offer insights into the landscape history and uplift of that region.

Hydrogeological uncertainties in delineation of leakage at karst dam sites, the Zagros Region, Iran, 2007, Mohammadi Z. And Raeisi E.
Leakage from dam reservoirs has been reported in different karst regions of the world. Water leakage occurs through the karst features directly or indirectly. The estimation of leakage locations, path(s), and quantity are subject to error due to uncertainties in the non-homogenous nature of a karst formation, method of study, and limited investigation due to time and cost factors. The conventional approaches for study on the karst development are local boring at the dam site and geological mapping. In this paper, uncertainties associated with conventional hydrogeological approaches are addressed from both qualitative and quantitative points of view. No major solution cavities were observed in boreholes and galleries of some dam sites in the Zagros Region, Iran, but huge karst conduits were discovered during the drilling of a diversion tunnel. This inconsistency is due to the point character of boreholes and the inherent nonhomogeneity of karst. The results of dye tracing tests in boreholes may be significantly affected by location of the injection and sampling points, as tests executed at the Saymareh and Tangab Dam sites in the Zagros Region, Iran show. The quantitative uncertainty of leakage is analyzed for diffuse and conduit flow systems for cases with and without any grout curtain, under the combined effect of input uncertainties at the Tangab Dam site, southern Iran. Assuming a diffuse flow system, the mean leakage at 95% confidence interval for both strategies is estimated at less than 5% of the mean annual discharge of the river. Accordingly, the dam can be constructed without the necessity of a grout curtain. However, assuming a conduit flow system, the results reveal a significant uncertainty. A small diameter conduit can convey significant amounts of water under high reservoir pressure heads. The leakage of a 4 m diameter conduit (cross section area of 12.5 m2) is 163 times more than the leakage of 0.5 m diameter conduit (cross sectional area of 0.2 m2) while the cross sectional area ratio is 60. The uncertainty may be decreased if a detailed study is carried out on the stratigraphic and tectonic settings, karst hydrogeology, geomorphology, speleogenesis, and by performing several dye tracing tests, especially outside the proposed grout curtain area.

On the essence of karst, 2010, Klimchouk, O. B. , Andreychouk, V. N.

The long-lasting uncertainty with the central for karstology notion of karst hinders synthesis of knowledge and the development of a theoretical basis of this scientific discipline. This paper analyses the essence of karst, based on generalization of the modern ideas about regularities of the origin and evolution of conduit permeability in soluble rocks, viewed in the light of ideas of synergetics and non-equilibrium thermodynamics of I.P.Prigogine regarding self-organization in open systems and formation of ordered dissipative structures.

The presence of soluble rocks in the sedimentary environment determines a phenomena of self-organization of the flow structure, which brings the water-rock system into a new capacity-state, namely karstic. The property of self-organization of this geosystem realizes via specific (speleogenetic) mechanism of permeability development, which action radically changes (organizes in a special manner) the structure and functioning of the flow system.

The mechanism of self-organization of flow and of the formation of the karst geosystem (speleogenesis) includes: 1) early speleogenesis, positive feedback between flow and the rate of enlargement of initial flow paths (revealing of proto-conduits), 2) speleogenetic initiation: a cascade breakthroughs of proto-conduits to the condition of rapid dissolution kinetics, with accelerated growth of initiated conduits, hydrodynamic competition, respective destabilization and reorganization of the flow pattern and change in boundary conditions, and, 3) speleogenetic development: stabilization of the system at dynamic equilibrium at the expense of increased energy exchange with the environment, and further growth of conduits. As a result of this specific evolution the geosystem acquires new, karstic, capacity and more complex of organization, with the establishment of one more level of permeability, the most contrast one.

The notion of karst is derived from the essence of progressive evolution of the geosystem containing permeable soluble rocks, driven by water exchange and speleogenetic mechanism of self-organization of the permeability structure. Regressive evolution of the karst geosystem includes processes of gravitational destruction and various accumulations, which lead to fragmentation and demolition of relict structures of karst permeability. Based on this new approach to definition of the notion of karst, criteria of distinction between proper karst and similar but not identical phenomena (merokarst, pseudokarst) are discussed.

Resolving Carbonate Complexity, 2010, Almarzouqi M. I. , Bush I. , Griffiths R. , Husser A. , Jeha Z. , Montaron B. , Narhari S. R. , Poiriercoutansais X.

Assessing basic rock properties using traditional logging suites—usually a straightforward
process in sandstone reservoirs—may be difficult or impossible in carbonate reservoirs. Also, when dealing with carbonates, determining optimal locations for new wells from petrophysical analysis often becomes little more than a statistical exercise. However, new tools, techniques and interpretation methodologies are helping petrophysicists unravel the complexities posed by carbonate reservoirs.
Equipped with this information, operators are able to drill and produce these reservoirs hile better managing uncertainty.

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.

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 %.

Thermal damping and retardation in karst conduits, 2015, Luhmann A. J. , Covington M. D. , Myre J. M. , Perne M. , Jones S. W. , Alexander Jr. E. C. , Saar M. O

Water temperature is a non-conservative tracer in the environment. Variations in recharge temperature are damped and retarded as water moves through an aquifer due to heat exchange between water and rock. However,within karst aquifers, seasonal and short-term fluctuations in recharge temperature are often transmitted over long distances before they are fully damped. Using analytical solutions and numerical simulations, we develop relationshipsthat describe the effect of flow path properties, flow-through time, recharge characteristics, and water and rock physical properties on the damping and retardation of thermal peaks/troughs in karst conduits. Using these relationships, one can estimate the thermal retardation and damping that would occur under given conditions with a given conduit geometry. Ultimately, these relationships can be used with thermal damping and retardation field data to estimate parameters such as conduit diameter. We also examine sets of numerical simulations where we relax some of the assumptions used to develop these relationships, testing the effects of variable diameter, variable velocity, open channels, and recharge shape on thermal damping and retardation to provide some constraints on uncertainty. Finally, we discuss a multitracer experiment that provides some field confirmation of our relationships. High temporal resolution water temperature data are required to obtain sufficient constraints on the magnitude and timing of thermal peaks and troughs in order to take full advantage of water temperature as a tracer.


Results 16 to 30 of 31
You probably didn't submit anything to search for