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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. ...

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 lower confining bed is an impermeable bed underlying an aquifer [16].?

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Your search for biscayne aquifer (Keyword) returned 10 results for the whole karstbase:
Use of stable isotopes to quantify flows between the Everglades and urban areas in Miami-Dade County Florida, 2004, Wilcox W. M. , Sologabriele H. M. , Sternberg L. O. R. ,
An isotopic study was performed to assess the movement of groundwater for a site located in Miami-Dade County, Florida. The site encompasses portions of a protected wetland environment (northeast Everglades National Park) and suburban residential Miami, incorporating municipal pumping wells and lakes formed by rock mining. Samples of ground, surface, and rainwater were analyzed for their isotopic composition (oxygen-18 and deuterium). Various analytical and graphical techniques were used to analyze this data and two conceptual box models were developed to quantify flows between different regions within the site. Results from this study indicate that the aquifer underlying the study site (the Biscayne aquifer) is highly transmissive with the exception of two semi-confining layers of reduced hydraulic conductivity. Everglades surface water infiltrates into the aquifer and migrates east toward residential areas. In these urban areas, 'shallow' groundwater (above the deeper semi-confining layer) is substantially affected by urban rainfall while 'deep' groundwater (below the deeper semi-confining layer) maintains a composition similar to that of Everglades water. Rock mining lakes in the area provide 'breaks' in the semi-confining layers that allow for mixing of shallow and deep groundwater. As water travels eastward, municipal well intakes, screened to a depth below the deeper semi-confining layer, draw upon not only shallow urban water (predominantly comprised of urban rainfall) and lake water (having influences from both urban rainfall and Everglades water) but also deep water that originated in the Everglades. Results from one of the box models estimate that over 60% of the water being removed by municipal pumping originated in the Everglades. These conclusions suggest that Everglades water, both directly through deep groundwater flow and indirectly through mixing with rock-mining lakes, is being drawn into the operating municipal wellfield.

Assessing the Vulnerability of a Municipal Well Field to Contamination in a Karst Aquifer, 2005, Renken R. A. , Cunningham K. J. , Zygnerski M. R. , Wacker M. A. , Shapiro A. M. , Harvey R. W. , Metge D. W. , Osborn C. L. , Ryan J. N. ,
Proposed expansion of extractive lime-rock mines near the Miami-Dade County Northwest well field and Everglades wetland areas has garnered intense scrutiny by government, public, environmental stakeholders, and the media because of concern that mining will increase the risk of pathogen contamination. Rock mines are excavated to the same depth as the well field's primary producing zone. The underlying karst Biscayne aquifer is a triple-porosity system characterized by (1) a matrix of interparticle porosity and separate vug porosity; (2) touching-vug porosity that forms preferred, stratiform passageways; and, less commonly, (3) conduit porosity formed by thin solution pipes, bedding-plane vugs, and cavernous vugs. Existing ground-water flow and particle tracking models do not provide adequate information regarding the ability of the aquifer to limit the advective movement of pathogens and other contaminants. Chemical transport and colloidal mobility properties have been delineated using conservative and microsphere-surrogate tracers for Cryptosporidium parvum. Forced-gradient tests were executed by introducing conservative tracers into injection wells located 100 m (328 ft) from a municipal-supply well. Apparent mean advective velocity between the wells is one to two orders of magnitude greater than previously measured. Touching-vug, stratiform flow zones are efficient pathways for tracer movement at the well field. The effective porosity for a continuum model between the point of injection and tracer recovery ranges from 2 to 4 percent and is an order of magnitude smaller than previously assumed. Existing well-field protection zones were established using porosity estimates based on specific yield. The effective, or kinematic, porosity of a Biscayne aquifer continuum model is lower than the total porosity, because high velocities occur along preferential flow paths that result in faster times of travel than can be represented with the ground-water flow equation. Tracer tests indicate that the relative ease of contaminant movement to municipal supply wells is much greater than previously considered

Identifying and characterizing solution conduits in karst aquifers through geospatial (GIS) analysis of porosity from borehole imagery: An example from the Biscayne aquifer, South Florida (USA), 2006, Manda A. K. , Gross M. R. ,
We apply geospatial analysis to borehole imagery in an effort to develop new techniques to evaluate the spatial distribution and internal structure of karst conduits. Remote sensing software is used to classify a high resolution, digital borehole image of limestone bedrock from the Biscayne aquifer (South Florida, USA) into a binary image divided into cells of rock matrix and pores. Within a GIS, 2D porosity is calculated for a series of rectangular sampling windows placed over the binary image and then plotted as a function of depth. Potential conduits that intersect the borehole are identified as peaks of high porosity. A second GIS technique identifies a conduit as a continuous object that spans the entire borehole width. According to these criteria, geospatial analysis reveals similar to 10 discrete conduits along the similar to 15 m borehole image. Continuous sampling of the geologic medium intersected by the borehole provides insight into the internal structure of karst aquifers and the evolution of karst features. Most importantly, this pilot study demonstrates that GIS-based techniques are capable of quantifying the depths, dimensions, shapes, apertures and connectivity of potential conduits, physical attributes that impact flow in karst aquifers. (c) 2005 Elsevier Ltd. All rights reserved

Application of carbonate cyclostratigraphy and borehole geophysics to delineate porosity and preferential flow in the karst limestone of the Biscayne Aquifer, SE Florida, 2006, Cunningham K. J. , Renken R. A. , Wacker M. A. , Zygnerski M. R. , Robinson E. , Shapiro A. M. , Wingard G. L.

NMR Imaging of Fluid Exchange between Macropores and Matrix in Eogenetic Karst, 2009, Florea L. J. , Cunningham K. J. , Altobelli S.

Sequential time-step images acquired using nuclear magnetic resonance (NMR) show the displacement of deuterated water (D2O) by fresh water within two limestone samples characterized by a porous and permeable limestone matrix of peloids and ooids. These samples were selected because they have a macropore system representative of some parts of the eogenetic karst limestone of the Biscayne Aquifer in southeastern Florida. The macroporosity, created by the trace fossil Ophiomorpha, is principally well connected and of centimeter scale. These macropores occur in broadly continuous stratiform zones that create preferential flow layers within the Hydrogeologic units of the Biscayne. This arrangement of porosity is important because in coastal areas, it could produce a preferential pathway for salt water intrusion. Two experiments were conducted in which samples saturated with D2O were placed in acrylic chambers filled with fresh water and examined with NMR. Results reveal a substantial flux of fresh water into the matrix porosity with a simultaneous loss of D2O. Specifically, we measured rates upward of 0.001 mL/h/g of sample in static conditions, and perhaps as great as 0.07 mL/h/g of sample when fresh water continuously flows past a sample at velocities less than those found within stressed areas of the Biscayne. These experiments illustrate how fresh water and D2O, with different chemical properties, migrate within one type of matrix porosity found in the Biscayne. Furthermore, these experiments are a comparative exercise in the displacement of sea water by fresh water in the matrix of a coastal, karst aquifer since D2O has a greater density than fresh water.


Multiple technologies applied to characterization of the porosity and permeability of the Biscayne aquifer, Florida, 2011, Cunningham K. J. , Sukop M. C.

Research is needed to determine how seepage-control actions planned by the Comprehensive Everglades Restoration Plan (CERP) will affect recharge, groundwater flow, and discharge within the dual-porosity karstic Biscayne aquifer where it extends eastward from the Everglades to Biscayne Bay. A key issue is whether the plan can be accomplished without causing urban flooding in adjacent populated areas and diminishing coastal freshwater flow needed in the restoration of the ecologic systems. Predictive simulation of groundwater flow is a prudent approach to understanding hydrologic change and potential ecologic impacts. A fundamental problem to simulation of karst groundwater flow is how best to represent aquifer heterogeneity. Currently, U.S. Geological Survey (USGS) researchers and academic partners are applying multiple innovative technologies to characterize the spatial distribution of porosity and permeability within the Biscayne aquifer.


Carbonate Aquifers, 2012, Cunningham K. J. , Sukop M. C. , Curran H. A.

Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.


Carbonate Aquifers, 2012, Cunningham K. J. , Sukop M. C. , Curran H. A.

Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.


Evaluation of permeability and non-Darcy flow in vuggy macroporous limestone aquifer samples with lattice Boltzmann methods, 2013, Sukop M. C. , Huang H. , Alvarez P. F. , Variano E. A. , Cunningham K. J.

Lattice Boltzmann flow simulations provide a physics-based means of estimating intrinsic permeability from pore structure and accounting for inertial flow that leads to departures from Darcy’s law. Simulations were used to compute intrinsic permeability where standard measurement methods may fail and to provide better understanding of departures from Darcy’s law under field conditions. Simulations also investigated resolution issues. Computed tomography (CT) images were acquired at 0.8 mm interscan spacing for seven samples characterized by centimeter-scale biogenic vuggy macroporosity from the extremely transmissive sole-source carbonate karst Biscayne aquifer in southeastern Florida. Samples were as large as 0.3 m in length; 7–9 cm-scale-length subsamples were used for lattice Boltzmann computations. Macroporosity of the subsamples was as high as 81%. Matrix porosity was ignored in the simulations. Non-Darcy behavior led to a twofold reduction in apparent hydraulic conductivity as an applied hydraulic gradient increased to levels observed at regional scale within the Biscayne aquifer; larger reductions are expected under higher gradients near wells and canals. Thus, inertial flows and departures from Darcy’s law may occur under field conditions. Changes in apparent hydraulic conductivity with changes in head gradient computed with the lattice Boltzmann model closely fit the Darcy-Forchheimer equation allowing estimation of the Forchheimer parameter. CT-scan resolution appeared adequate to capture intrinsic permeability; however, departures from Darcy behavior were less detectable as resolution coarsened.


Characterizing moldic and vuggy pore space in karst aquifers using borehole-wall, slabbed-core and thin-section images, 2013, Manda A. K. , Culpepper A. R.

Carbonate aquifers are prolific and important sources of potable water in many parts of the world owing toenlarged dissolution features that enhance porosity and interconnectivity. To better understand the variationsof pore space in different karst aquifers, image and geospatial analyses are used to analyze pore attributes(i.e., pore area and perimeter) in images of vuggy aquifers. Pore geometry and 2D porosity derivedfrom images of the moldic Castle Hayne and vuggy Biscayne aquifers are analyzed at three scales of observation:borehole televiewer, core and thin-section. The Castle Hayne and Biscayne aquifers are the foci of thisstudy because the pore spaces that control the hydrologic properties in each of these aquifers are markedlydifferent even though both of these carbonate reservoirs are prolific aquifers. Assessments of pore area,perimeter and shape index (a measure of shape complexity) indicate that pore geometries and pore complexitiesvary as a function pore type and scale of observation. For each aquifer type, the areas, perimetersand complexities of pores are higher at the larger scale of observation (e.g., borehole) than the smallerscale of observation (e.g., thin section). When the complexity of the moldic pores is compared to the complexityof vuggy pores, the results indicate that moldic pores are generally more complex than vuggy poresat the same scale of observation. Whereas estimates of 2D porosity from the borehole televiewer image ofthe vuggy aquifer are higher than those derived from the moldic aquifer, the range of 2D porosities is largerin core and thin section images for the vuggy aquifer than themoldic aquifer. A model for the development ofpores is presented that suggests that the coalescence of small pores with simple shapes leads to the growth oflarger pores with more complex shapes. The model suggests that the younger Biscayne aquifer is a moremature karst than the Castle Hayne aquifer.


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