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Full-Text Articles in Physical Sciences and Mathematics

The Role Of Mites In The Construction And Weathering Of Siliceous Biospeleothems, María José López-Galindo Nov 2018

The Role Of Mites In The Construction And Weathering Of Siliceous Biospeleothems, María José López-Galindo

International Journal of Speleology

Acarines are well-documented as formative elements in the biocenosis of soils. However, their role in the construction and weathering of siliceous speleothems has received very little attention in previous research. The present study describes different groups of cavities (nesting/molting sites) excavated by these organisms in the surface of siliceous speleothems that are deposited in the fissures between various granite boulders in Southern Spain. There is evidence that there are immature stages that would survive the heat and drought of summer in the form of small larvae, or euedaphic nymphs, in the soil. This study provides the first description of how …


High-Precision Lead Isotope Analysis On Modern Populations To Determine Geolocation Reliability, Gennifer M. Goad Nov 2018

High-Precision Lead Isotope Analysis On Modern Populations To Determine Geolocation Reliability, Gennifer M. Goad

USF Tampa Graduate Theses and Dissertations

Forensic anthropologists increasingly use chemical isotope analysis in the investigation of unidentified human remains, as biochemical georeferencing continually improves with the development of modern reference data of known origins. Isotope variations in trace elements such as strontium (Sr) and lead (Pb) in human teeth are some of the most useful indicators of past domicile in archaeological research and thus have high potential for modern, forensic applications. In this study, high-precision lead isotope analysis was conducted on 63 modern human teeth, which were previously analyzed for strontium isotopes. The results present new lead isotope data for the following countries: United States …


The Utility Of The Conductivity Mass-Balance Method For Base Flow Separation In Rivers And Streams, Darline Alegria Lott Nov 2018

The Utility Of The Conductivity Mass-Balance Method For Base Flow Separation In Rivers And Streams, Darline Alegria Lott

USF Tampa Graduate Theses and Dissertations

Freshwater for ecosystems, drinking water, and water for various businesses are important resources and those resources are rapidly diminishing globally due to drought and overuse. In order to manage the availability of water for all concerned, good estimates of base flow (groundwater) is required. Base flow, a component of streamflow, is deduced by separating a stream hydrograph into two components, base flow and runoff. There are several techniques used to perform base flow separation; however two techniques are used in this study, chemical mass-balance and analytical methods. This dissertation explains how an analytical technique was derived from a mass-balance method, …


Evolution Of Noble Gas And Water Isotopes Along The Regional Groundwater Flow Path Of The Konya Closed Basin, Turkey, N. Nur Ozyurt, C. Serdar Bayari Nov 2018

Evolution Of Noble Gas And Water Isotopes Along The Regional Groundwater Flow Path Of The Konya Closed Basin, Turkey, N. Nur Ozyurt, C. Serdar Bayari

International Journal of Speleology

Noble gas and water isotope compositions of regional groundwater were investigated along two transects in the Konya Closed Basin (KCB) of central Turkey. According to the 3He/4He versus Ne/He plot of samples, crust (up to 86%) and mantle (up to 26%) appear to be the primary and secondary sources of dissolved He in groundwater, respectively. After the beginning of both transects where the flow domain is confined, both 3He and 4He accumulate steadily in groundwater. Thereafter, the intermediate recharge from the surface in the unconfined part of regional flow system disrupts the steady accumulation trend …


Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood Nov 2018

Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood

International Journal of Speleology

The Upper Geyser Basin in Yellowstone National Park occurs over a siliceous hydrothermal terrane containing numerous hot springs and geysers. The pool and vent-conduit geometries of these hydrothermal features share a resemblance to conventional karst features known from other rock types, suggesting karst processes could be responsible for their origin and/or evolution. Hypogene speleogenesis is a cave-forming process in which the formation of caves is decoupled from and occurs independently of surface recharge. The geologic setting for hypogene speleogenesis typically occurs at the distal end of regional groundwater systems wherein the hydrogeology is manifested by ascending fluids and/or by geochemical …


Assessing The Cooling Effects Of Urban Vegetation On Urban Heat Mitigation In Selected U.S. Cities, Qiuyan Yu Nov 2018

Assessing The Cooling Effects Of Urban Vegetation On Urban Heat Mitigation In Selected U.S. Cities, Qiuyan Yu

USF Tampa Graduate Theses and Dissertations

Urban Heat Island (UHI) is a growing problem worldwide. Mitigation of UHI is necessary for cities to adapt to climate change and enhance sustainable development at a city scale. Cooling cities with urban vegetation management is a sustainable solution for urban heat mitigation. Urban vegetation influences urban microclimate through the shading effect, surface roughness, and evapotranspiration. The differences in horizontal and vertical structures of urban vegetation determine the shading effect, surface roughness, and evapotranspiration. Enhancing the cooling effect of urban vegetation requires a comprehensive understanding of how vegetation structure affects UHI. The effects of horizontal structure on land surface temperature …


Enhancement Of Rainfall-Triggered Shallow Landslide Hazard Assessment At Regional And Site Scales Using Remote Sensing And Slope Stability Analysis Coupled With Infiltration Modeling, Thilanki Maneesha Dahigamuwa Rajaguru Mudiyanselage Nov 2018

Enhancement Of Rainfall-Triggered Shallow Landslide Hazard Assessment At Regional And Site Scales Using Remote Sensing And Slope Stability Analysis Coupled With Infiltration Modeling, Thilanki Maneesha Dahigamuwa Rajaguru Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Landslides cause significant damage to property and human lives throughout the world. Rainfall is the most common triggering factor for the occurrence of landslides. This dissertation presents two novel methodologies for assessment of rainfall-triggered shallow landslide hazard. The first method focuses on using remotely sensed soil moisture and soil surface properties in developing a framework for real-time regional scale landslide hazard assessment while the second method is a deterministic approach to landslide hazard assessment of the specific sites identified during first assessment. In the latter approach, landslide inducing transient seepage in soil during rainfall and its effect on slope stability …


Optical Remote Sensing Of Oil Spills In The Gulf Of Mexico, Shaojie Sun Nov 2018

Optical Remote Sensing Of Oil Spills In The Gulf Of Mexico, Shaojie Sun

USF Tampa Graduate Theses and Dissertations

Assessment of oil spills in the ocean using passive remote sensing (i.e., reflected sun light) faces two challenges: detect oil presence/absence and quantify oil volume. While the optical properties of oil allow it to be differentiated from the surrounding marine environment, sun glint can facilitate oil presence/absence detection because the oil-water spatial contrast is enhanced due to wave dampening. However, sun glint also modulates the magnitude and shape of the spectral reflectance of surface oil. In addition to this difficulty, the most critical challenge is how to quantify oil volume (or thickness) through remote sensing. To date, such quantifications have …


A Review Of Fractals In Karst, Eulogio Pardo-Igúzquiza, Peter A. Dowd, Juan J. Durán, Pedro Robledo-Ardila Nov 2018

A Review Of Fractals In Karst, Eulogio Pardo-Igúzquiza, Peter A. Dowd, Juan J. Durán, Pedro Robledo-Ardila

International Journal of Speleology

Many features of a karst massif can either be modelled using fractal geometry or have a fractal distribution. For the exokarst, typical examples include the geometry of the landscape and the spatial location and size-distribution of karst depressions. Typical examples for the endokarst are the geometry of the three-dimensional network of karst conduits and the length-distribution of caves. In addition, the hydrogeological parameters of the karst massif, such as hydraulic conductivity, and karst spring hydrographs may also exhibit fractal behaviour. In this work we review the karst features that exhibit fractal behaviour, we review the literature in which they are …


Do Slow Slip Events Trigger Large And Great Megathrust Earthquakes?, N. Voss, Timothy H. Dixon, Z. Liu, Rocco Malservisi, M. Protti, S. Schwartz Oct 2018

Do Slow Slip Events Trigger Large And Great Megathrust Earthquakes?, N. Voss, Timothy H. Dixon, Z. Liu, Rocco Malservisi, M. Protti, S. Schwartz

School of Geosciences Faculty and Staff Publications

Slow slip events have been suggested to trigger subduction earthquakes. However, examples to date have been poorly recorded, occurring offshore, where data are sparse. Better understanding of slow slip events and their influence on subsequent earthquakes is critical for hazard forecasts. We analyze a well-recorded event beginning 6 months before the 2012 Mw (moment magnitude) 7.6 earthquake in Costa Rica. The event migrates to the eventual megathrust rupture. Peak slip rate reached a maximum of 5 mm/day, 43 days before the earthquake, remaining high until the earthquake. However, changes in Mohr-Coulomb failure stress at the hypocenter were small (0.1 …


Remote Estimation Of Surface Water PCo2 In The Gulf Of Mexico, Shuangling Chen Oct 2018

Remote Estimation Of Surface Water PCo2 In The Gulf Of Mexico, Shuangling Chen

USF Tampa Graduate Theses and Dissertations

Surface ocean partial pressure of CO2 (pCO2) is a critical parameter in the quantification of air-sea CO2 flux, which further plays an important role in quantifying the global carbon budget and understanding ocean acidification. The demand for a clearer understanding of how, and how fast, the ocean is changing due to atmospheric CO2 absorption, requires accurate and synoptic estimation of surface pCO2.

Surface ocean pCO2 is mainly controlled by four oceanic processes – thermodynamics, ocean mixing, biological activities, and air-sea CO2 exchange. Surface ocean pCO2 …


Ice And Guano Deposits In El Malpais Lava Tubes: Potential Paleoclimate Archives For The Southwest United States, Dylan S. Parmenter Oct 2018

Ice And Guano Deposits In El Malpais Lava Tubes: Potential Paleoclimate Archives For The Southwest United States, Dylan S. Parmenter

USF Tampa Graduate Theses and Dissertations

Three ice cores and one guano core were obtained from lava tubes in El Malpais National Monument, New Mexico, in the Southwest United States. A large hiatus in the Bat Cave guano record, resulting from mining activities in the early 1900's, left us with only ~50 years of data (from AD 1955-2006) to use in analysis. 13C values in guano (-18 to -11.6‰) primarily fall within the range of C4 plants, and likely indicate a tendency of Tadarida brasiliensis to feed on insects over grasslands to the North or South of the park. Variations in 13C values for this period …


Morphodynamics Of Shell Key And Mullet Key Barrier Islands: Their Origin And Development, Zachary J. Westfall Oct 2018

Morphodynamics Of Shell Key And Mullet Key Barrier Islands: Their Origin And Development, Zachary J. Westfall

USF Tampa Graduate Theses and Dissertations

Shell Key and Mullet Key are two sandy barrier islands on the West Central Florida coast near the mouth of Tampa Bay. These islands are part of an interconnected barrier-inlet system that includes Pass-a-Grille (PAG) and Bunces Pass. Shell Key is a relatively new island about 40-years of age that formed in between the two inlets of Bunces Pass and PAG. Mullet Key is an island to the south of Shell Key situated between Bunces Pass and the main Tampa Bay channel that has demonstrated large scale upward shoaling events. Using numerical modeling, the wave and tidal conditions at the …


The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta Oct 2018

The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta

International Journal of Speleology

The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif …


Application Of Image Recognition Technology To Foraminiferal Assemblage Analyses, Christian Helmut Gfatter Oct 2018

Application Of Image Recognition Technology To Foraminiferal Assemblage Analyses, Christian Helmut Gfatter

USF Tampa Graduate Theses and Dissertations

Analyses of foraminiferal assemblages involve time consuming microscopic assessment of sediment samples. Image recognition software, which systematically matches features within sample images against an image library, is widely used in contexts ranging from law enforcement to medical research. At present, scientific applications such as identification of specimens in plankton samples utilize flow through systems in which samples are suspended in liquid and pass through a beam of light where the images are captured using transmitted light. Identification of foraminifers generally utilizes reflected light, because most shells are relatively opaque.

My goal was to design and test a protocol to directly …


On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. Mcfarlane Oct 2018

On Biospeleothems From A Venezuelan Tepui Cave: U-Th Dating, Growth Rates, And Morphology, Joyce Lundberg, Charles Brewer-Carías, Donald A. Mcfarlane

International Journal of Speleology

Seven silica biospeleothems from Cueva Charles Brewer, Chimantá Plateau, Venezuela have been successfully U-Th dated despite very low U and high detrital Th concentrations. Growth rates are low, between ~100 to ~800 µm/ka, and are greater closer to water level. Dates in unaltered material are in good stratigraphic order, but secondary silicification may compromise the U-Th system, yielding unreliable sequences of ages. Detritally-enriched layers correlate with global climate cycles of the Late Quaternary, in particular the cooler, drier phases of MIS 5d, 5a, and 4. SEM studies indicate that the peloidal material is made up of silica nano-particles assembled to …


Correlates Of Rate Heterogeneity In Avian Ecomorphological Traits, A. M. Chira, C. R. Cooney, Jen A. Bright, E. J. R. Capp, E. C. Hughes, C. J. A. Moody, L. O. Nouri, Z. K. Varley, G. H. Thomas Oct 2018

Correlates Of Rate Heterogeneity In Avian Ecomorphological Traits, A. M. Chira, C. R. Cooney, Jen A. Bright, E. J. R. Capp, E. C. Hughes, C. J. A. Moody, L. O. Nouri, Z. K. Varley, G. H. Thomas

School of Geosciences Faculty and Staff Publications

Heterogeneity in rates of trait evolution is widespread, but it remains unclear which processes drive fast and slow character divergence across global radiations. Here, we test multiple hypotheses for explaining rate variation in an ecomorphological trait (beak shape) across a globally distributed group (birds). We find low support that variation in evolutionary rates of species is correlated with life history, environmental mutagenic factors, range size, number of competitors, or living on islands. Indeed, after controlling for the negative effect of species' age, 80% of variation in species‐specific evolutionary rates remains unexplained. At the clade level, high evolutionary rates are associated …


Sulfur (34S/32S) Isotope Composition Of Gypsum And Implications For Deep Cave Formation On The Nullarbor Plain, Australia, Matej Lipar, Mateja Ferk, Sonja Lojen, Milo Barham Sep 2018

Sulfur (34S/32S) Isotope Composition Of Gypsum And Implications For Deep Cave Formation On The Nullarbor Plain, Australia, Matej Lipar, Mateja Ferk, Sonja Lojen, Milo Barham

International Journal of Speleology

Large deep caves with little relation to surface topography are distinctive karst features on the Nullarbor Plain of Australia. The presence of gypsum deposits and chemoautotrophic bacteria within the caves have been suggested as evidence for cave formation and (or) enlargement via sulfuric acid speleogenesis. To test this hypothesis, the stable sulfur isotope compositions (δ34S) of both cave gypsum and surface gypsum were measured. Analyses yielded relatively high, positive δ34S values from both cave gypsum and surface gypsum, arguing against gypsum genesis via microbial chemoautotrophy, and more broadly, sulfuric acid speleogenesis. Instead, the gypsum is interpreted …


Evidence For Subsurface Origin Of Boulder Caves, Roofed Slots And Boulder-Filled Canyons (Broumov Highland, Czechia), Filip Duszyński, Kacper Jancewicz, Piotr Migoń Sep 2018

Evidence For Subsurface Origin Of Boulder Caves, Roofed Slots And Boulder-Filled Canyons (Broumov Highland, Czechia), Filip Duszyński, Kacper Jancewicz, Piotr Migoń

International Journal of Speleology

The backslope of a sandstone cuesta in the Broumov Highland (Czechia) is cut by a complex network of canyons. Long sections of canyons have thick boulder fills which are difficult to reconcile with simple rock fall and talus development scenario. Boulder caves occur within these fills and their lowermost parts are drained by streams that evacuate fine loose sandy material produced by weathering and mechanical erosion. These boulder fills are explained as largely in situ, residual features, left after subsurface selective disintegration of rock mass, mainly joint-guided, and removal of grains by underground water. Evacuation of fines leaves voids …


Impact Of Climate Change On The Transition Of Neanderthals To Modern Humans In Europe, Michael Staubwasser, Virgil Drăgușin, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, Daniel Veres Sep 2018

Impact Of Climate Change On The Transition Of Neanderthals To Modern Humans In Europe, Michael Staubwasser, Virgil Drăgușin, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, Daniel Veres

School of Geosciences Faculty and Staff Publications

Two speleothem stable isotope records from East-Central Europe demonstrate that Greenland Stadial 12 (GS12) and GS10—at 44.3–43.3 and 40.8–40.2 ka—were prominent intervals of cold and arid conditions. GS12, GS11, and GS10 are coeval with a regional pattern of culturally (near-)sterile layers within Europe’s diachronous archeologic transition from Neanderthals to modern human Aurignacian. Sterile layers coeval with GS12 precede the Aurignacian throughout the middle and upper Danube region. In some records from the northern Iberian Peninsula, such layers are coeval with GS11 and separate the Châtelperronian from the Aurignacian. Sterile layers preceding the Aurignacian in the remaining Châtelperronian domain are coeval …


Replacement Times Of A Spectrum Of Elements In The North Atlantic Based On Thorium Supply, Christopher T. Hayes, Robert F. Anderson, Hai Cheng, Tim M. Conway, R. L. Edwards, Martin Q. Fleisher, Peng Ho, Kuo-Fang Huang, Seth G. John, William M. Landing Sep 2018

Replacement Times Of A Spectrum Of Elements In The North Atlantic Based On Thorium Supply, Christopher T. Hayes, Robert F. Anderson, Hai Cheng, Tim M. Conway, R. L. Edwards, Martin Q. Fleisher, Peng Ho, Kuo-Fang Huang, Seth G. John, William M. Landing

School of Geosciences Faculty and Staff Publications

The measurable supply of 232Th to the ocean can be used to derive the supply of other elements, which is more difficult to quantify directly. The measured inventory of an element divided by the derived supply yields a replacement time estimate, which in special circumstances is related to a residence time. As a proof of concept, Th‐based supply rates imply a range in the replacement times of the rare earth elements in the North Atlantic that is consistent with the chemical reactivity of rare earth elements related to their ionic charge density. Similar estimates of replacement times for the …


Tracking Submarine Volcanic Activity At Monowai: Constraints From Long‐Range Hydroacoustic Measurements, D. Metz, A. B. Watts, I. Grevemeyer, Mel Rodgers Sep 2018

Tracking Submarine Volcanic Activity At Monowai: Constraints From Long‐Range Hydroacoustic Measurements, D. Metz, A. B. Watts, I. Grevemeyer, Mel Rodgers

School of Geosciences Faculty and Staff Publications

Monowai is a submarine volcanic center in the Kermadec Arc, Southwest Pacific Ocean. In the past, activity at the volcano had been intermittently observed in the form of fallout at the sea surface, discolored water, changes in seafloor topography, and T phase seismicity, but there is no continuous record for more recent years. In this study, we investigated 3.5 years of recordings at a hydrophone array of the International Monitoring System, located near Juan Fernández Islands, for long‐range underwater sound waves from Monowai. Results from direction‐of‐arrival calculations and density‐based spatial clustering indicate that 82 discrete episodes of activity occurred between …


Kinetic Processes And Stable Isotopes In Cave Dripwaters As Indicators Of Winter Severity, Vasile Ersek, Bogdan P. Onac, Aurel Perșoiu Aug 2018

Kinetic Processes And Stable Isotopes In Cave Dripwaters As Indicators Of Winter Severity, Vasile Ersek, Bogdan P. Onac, Aurel Perșoiu

School of Geosciences Faculty and Staff Publications

We examine how the stable isotope composition of meteoric water is transmitted through soil and epikarst to dripwaters in a cave in western Romania. δ2H and δ18O in precipitation at this site are influenced by temperature and moisture sources (Atlantic and Mediterranean), with lower δ18O in winter and higher in summer. The stable isotope composition of cave dripwaters mimics this seasonal pattern of low and high δ18O, but the onset and end of freezing conditions in the winter season are marked by sharp transitions in the isotopic signature of cave dripwaters of …


Cultural Conundrums In African Land Governance: Agribusiness In Sierra Leone, Fenda A. Akiwumi Aug 2018

Cultural Conundrums In African Land Governance: Agribusiness In Sierra Leone, Fenda A. Akiwumi

School of Geosciences Faculty and Staff Publications

This paper deals with the disjuncture between recognition of the important role of culture in sustainable development discourse embedded in African regional and state policies and legal instruments and the reality of externally driven neoliberal land-based development agendas in African nations. Using postcolonial theoretical notions of identity, subalterns and representation, and the centuries-old African landlord-stranger institution as an important customary land management system operating at the local level, I explore some inherent conflicts between the landlord-stranger institution and state land governance. I interrogate this dilemma in the context of agribusiness development projects and land grabbing claims in Sierra Leone, West …


The Geotraces Intermediate Data Product 2017, Conwaygeotraces, Tim M. Conway Aug 2018

The Geotraces Intermediate Data Product 2017, Conwaygeotraces, Tim M. Conway

School of Geosciences Faculty and Staff Publications

The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results …


Convergent Evolution In The Euarchontoglires, Philip J.R. Morris, Samuel N.F. Cobb, Philip G. Cox Aug 2018

Convergent Evolution In The Euarchontoglires, Philip J.R. Morris, Samuel N.F. Cobb, Philip G. Cox

School of Geosciences Faculty and Staff Publications

Convergence—the independent evolution of similar phenotypes in distantly related clades—is a widespread and much-studied phenomenon. An often-cited, but hitherto untested, case of morphological convergence is that between the aye-aye and squirrels. The aye-aye (Daubentonia madagascariensis) is a highly unusual lemuriform primate that has evolved a dentition similar to that of rodents: it possesses large, ever-growing incisors which it uses to strip the bark from trees in order to feed on wood-boring beetle larvae. Indeed, such is the similarity that some of the earliest classifications of the aye-aye placed it in the squirrel genus Sciurus. Here, we aimed …


Vertical Structure Of Diurnal Englacial Hydrology Cycle At Helheim Glacier, East Greenland, Irena Vaňková, Denis Voytenko, Keith W. Nicholls, Surui Xie, Byron R. Parizek, David M. Holland Aug 2018

Vertical Structure Of Diurnal Englacial Hydrology Cycle At Helheim Glacier, East Greenland, Irena Vaňková, Denis Voytenko, Keith W. Nicholls, Surui Xie, Byron R. Parizek, David M. Holland

School of Geosciences Student Publications

The interior dynamics of Helheim Glacier were monitored using an autonomous phase‐sensitive radio‐echo sounder (ApRES) during two consecutive summers. The return signals from all observational sites exhibited strong non‐tidal, depth‐dependent diurnal variations. We show that these variations in the glacier interior can be explained by an englacial diurnal meltwater cycle: a data interpretation that assumes constant ice‐column composition through time leads to dynamical inconsistencies with concurrent observations from GPS and terrestrial radar. The observed diurnal meltwater cycle is spatially variable, both between different sites and in the vertical, consistent with the existence of a dense and complex englacial hydrologic network. …


Old And Recent Processes In A Warm And Humid Desert Hypogene Cave: ‘A’Rak Na‘Asane, Israel, Amos Frumkin, Shlomi Aharon, Uri Davidovich, Boaz Langford, Yoav Negev, Micka Ullman, Anton Vaks, Shemesh Ya‘Aran, Boaz Zissu Jul 2018

Old And Recent Processes In A Warm And Humid Desert Hypogene Cave: ‘A’Rak Na‘Asane, Israel, Amos Frumkin, Shlomi Aharon, Uri Davidovich, Boaz Langford, Yoav Negev, Micka Ullman, Anton Vaks, Shemesh Ya‘Aran, Boaz Zissu

International Journal of Speleology

Recent environmental processes are studied in ʻA’rak Naʻasane Cave at the northern Judean Desert, Israel. The outer zone of the cave is heavily influenced by the outside environment through a large entrance, facilitating entry of air flow, fauna and humans, with minor cave-forming modifications. Conversely, the inner cave sustains humid and warm conditions, favoring modifications by condensation corrosion of convective air flow, associated with deposition of popcorn speleothems at the lower parts of dissolution pockets. The warm humid air of the inner cave may be associated with an underlying thermal water table. Active condensation corrosion is decreasing, possibly because of …


Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown Jul 2018

Unconfined Hypogene Evaporite Karst: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford, Jon T. Ehrhart, Adam F. Majzoub, Jessica M. Shields, Wesley A. Brown

International Journal of Speleology

Diverse karst phenomena occur throughout the Gypsum Plain where the Castile Formation crops out over ~1800 km2 in West Texas and southeastern New Mexico. Hypergene karst is extensive and widespread, while traditional hypogene karst manifestations (both caves and intrastratal dissolution) occur in high frequency in the western outcrop region where surface denudation has been the greatest so as to induce surficial breaching. Unconfined hypogene karst occurrences have been recently identified, including two general variations: 1) artesian-like discharge features; and 2) venting structures. Artesian-like discharge features arise at surficially-breached hypogene caves and through high permeability regions on the margins of …


Forewarned Is Forearmed: Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World By Timothy H. Dixon (2017), Jason Makansi Jul 2018

Forewarned Is Forearmed: Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World By Timothy H. Dixon (2017), Jason Makansi

Numeracy

Timothy H. Dixon. 2017. Curbing Catastrophe: Natural Hazards and Risk Reduction in the Modern World. (New York, NY: Cambridge University Press) 300 pp. ISBN 978-1108113663.

Curbing Catastrophe for the most part lives up to what is claimed in the foreword: “…a compelling account of recent and historical disasters, both natural and human-caused, drawing on common themes and providing a holistic understanding of hazards, disasters, and mitigation for anyone interested in this important and topical subject.” This is a pretty thorough treatment of an extraordinarily complex subject, and the gaps identified in this review should be considered explications more than …