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Articles 271 - 300 of 1880

Full-Text Articles in Earth Sciences

Tf1.3 Permanent Marshes, R. T. Kingsford, J. A. Catford, Mark C. Rains, B. J. Robson, D. A. Keith Jan 2020

Tf1.3 Permanent Marshes, R. T. Kingsford, J. A. Catford, Mark C. Rains, B. J. Robson, D. A. Keith

School of Geosciences Faculty and Staff Publications

No abstract provided.


Uncovering Host-Microbiome Interactions In Global Systems With Collaborative Programming: A Novel Approach Integrating Social And Data Sciences [Version 1; Peer Review: Awaiting Peer Review], Jenna Oberstaller, Swamy Rakesh Adapa, Guy Dayhoff Ii, Justin Gibbons, Gregory S. Herbert Jan 2020

Uncovering Host-Microbiome Interactions In Global Systems With Collaborative Programming: A Novel Approach Integrating Social And Data Sciences [Version 1; Peer Review: Awaiting Peer Review], Jenna Oberstaller, Swamy Rakesh Adapa, Guy Dayhoff Ii, Justin Gibbons, Gregory S. Herbert

School of Geosciences Faculty and Staff Publications

Microbiome data are undergoing exponential growth powered by rapid technological advancement. As the scope and depth of microbiome research increases, cross-disciplinary research is urgently needed for interpreting and harnessing the unprecedented data output. However, conventional research settings pose challenges to much-needed interdisciplinary research efforts due to barriers in scientific terminologies, methodology and research-culture. To breach these barriers, our University of South Florida OneHealth Codeathon was designed to be an interactive, hands-on event that solves real-world data problems. The format brought together students, postdocs, faculty, researchers, and clinicians in a uniquely cross-disciplinary, team-focused setting. Teams were formed to encourage equitable distribution …


F1.2 Permanent Lowland Rivers, R. T. Kingsford, R. Mac Nally, G. S. Giller, Mark C. Rains, A. H. Arthington, D. A. Keith Jan 2020

F1.2 Permanent Lowland Rivers, R. T. Kingsford, R. Mac Nally, G. S. Giller, Mark C. Rains, A. H. Arthington, D. A. Keith

School of Geosciences Faculty and Staff Publications

No abstract provided.


F2.3 Seasonal Freshwater Lakes, R. T. Kingsford, R. Mac Nally, Mark C. Rains, B. J. Robson, K. Irvine, D. A. Keith Jan 2020

F2.3 Seasonal Freshwater Lakes, R. T. Kingsford, R. Mac Nally, Mark C. Rains, B. J. Robson, K. Irvine, D. A. Keith

School of Geosciences Faculty and Staff Publications

No abstract provided.


F1.1 Permanent Upland Streams, R. T. Kingsford, R. Mac Nally, P. S. Giller, Mark C. Rains, M. Kelly-Quinn, A. H. Arthington, D. A. Keith Jan 2020

F1.1 Permanent Upland Streams, R. T. Kingsford, R. Mac Nally, P. S. Giller, Mark C. Rains, M. Kelly-Quinn, A. H. Arthington, D. A. Keith

School of Geosciences Faculty and Staff Publications

No abstract provided.


Serpentinization As A Route To Liberating Phosphorus On Habitable Worlds, Matthew Pasek, Arthur Omran, Carolyn Lang, Maheen Gull, Josh Abbatiello, Tian Feng, Lyle Garong, Heather Abbott-Lyon Jan 2020

Serpentinization As A Route To Liberating Phosphorus On Habitable Worlds, Matthew Pasek, Arthur Omran, Carolyn Lang, Maheen Gull, Josh Abbatiello, Tian Feng, Lyle Garong, Heather Abbott-Lyon

School of Geosciences Faculty and Staff Publications

Planetary habitability is in part governed by nutrient availability, including the availability of the element phosphorus. The nutrient phosphorus plays roles in various necessary biochemical functions, and its biogeochemical cycling has been proposed to be extremely slow due to a strong coupling to the rock cycle via mineral weathering. Here we show a route to P liberation from water-rock reactions that are thought to be common throughout the Solar System. We report the speciation of phosphorus in serpentinite rocks to include the ion phosphite (HPO32- with P3+) and show that reduction of phosphate to phosphite is predicted from thermodynamic models …


Factors Affecting The 2019 Atlantic Hurricane Season And The Role Of The Indian Ocean Dipole, Kimberly M. Wood, Philip J. Klotzbach, Jennifer M. Collins, Louis-Philippe Caron, Ryan E. Truchelut, Carl J. Schreck Jan 2020

Factors Affecting The 2019 Atlantic Hurricane Season And The Role Of The Indian Ocean Dipole, Kimberly M. Wood, Philip J. Klotzbach, Jennifer M. Collins, Louis-Philippe Caron, Ryan E. Truchelut, Carl J. Schreck

School of Geosciences Faculty and Staff Publications

The 2019 Atlantic hurricane season exhibited above‐average Accumulated Cyclone Energy—60% of which was produced by Hurricanes Dorian and Lorenzo. Most tropical cyclone (TC) activity was concentrated in a ~6‐week period from late August to early October. During the early part of the season, relatively TC‐unfavorable conditions persisted in the main development region (MDR). The MDR environment became largely favorable in September, followed by an abrupt shift back to less conducive conditions in October coincident with a strongly positive Indian Ocean Dipole (IOD). The IOD produced an El Niño‐like teleconnection pattern observed through 200‐hPa velocity potential anomalies. In the subtropical Atlantic, …


The Prebiotic Provenance Of Semi-Aqueous Solvents, Jennifer L. Lago, Bradley T. Burcar, Nicholas V. Hud, Rio Febrian, Christopher A. Mehta, Paul J. Bracher, Zachary D. Atlas, Matthew A. Pasek Jan 2020

The Prebiotic Provenance Of Semi-Aqueous Solvents, Jennifer L. Lago, Bradley T. Burcar, Nicholas V. Hud, Rio Febrian, Christopher A. Mehta, Paul J. Bracher, Zachary D. Atlas, Matthew A. Pasek

School of Geosciences Faculty and Staff Publications

The numerous and varied roles of phosphorylated organic molecules in biochemistry suggest they may have been important to the origin of life. The prominence of phosphorylated molecules presents a conundrum given that phosphorylation is a thermodynamically unfavorable, endergonic process in water, and most natural sources of phosphate are poorly soluble. We recently demonstrated that a semi-aqueous solvent consisting of urea, ammonium formate, and water (UAFW) supports the dissolution of phosphate and the phosphorylation of nucleosides. However, the prebiotic feasibility and robustness of the UAFW system are unclear. Here, we study the UAFW system as a medium in which phosphate minerals …


Utilizing Ecological Niche Modelling To Predict Habitat Suitability Of Eastern Equine Encephalitis In Florida, Claire Burch, Rebecca Loraamm, Thomas R. Unnasch, Joni A. Downs Jan 2020

Utilizing Ecological Niche Modelling To Predict Habitat Suitability Of Eastern Equine Encephalitis In Florida, Claire Burch, Rebecca Loraamm, Thomas R. Unnasch, Joni A. Downs

School of Geosciences Faculty and Staff Publications

Eastern Equine Encephalitis virus (EEEV) is a virus found predominantly east of the Mississippi River in the United States that can be fatal to both equines and humans. The disease has previously been most prolific in states like Florida, but there has been an increase in the prevalence in other states further up north on the east coast of the United States in recent years. The purpose of this research is to use the ecological niche modelling program Maxent to model EEEV habitat suitability probability. This research utilized data of fatality incidence in equine hosts, versus sentinel chicken infection data, …


Optimizing Arbovirus Surveillance Using Risk Mapping And Coverage Modelling, Joni A. Downs, Mehrdad Vaziri, George Deskins, William Kellner, Kristi M. Miley, Thomas R. Unnasch Jan 2020

Optimizing Arbovirus Surveillance Using Risk Mapping And Coverage Modelling, Joni A. Downs, Mehrdad Vaziri, George Deskins, William Kellner, Kristi M. Miley, Thomas R. Unnasch

School of Geosciences Faculty and Staff Publications

Diseases carried by mosquitoes and other arthropods endanger human health globally. Though costly, surveillance efforts are vital for disease control and prevention This paper describes an approach for strategically configuring targeted disease surveillance sites across a study area. The methodology combines risk index mapping and spatial optimization modelling. The risk index is used to identify demand for surveillance, and the maximum covering location problem is used to select a specified number of candidate surveillance sites that covers the maximum amount of risk. The approach is demonstrated using a case study where optimal locations for sentinel surveillance sites are selected for …


A Hydrologic Landscapes Perspective On Groundwater Connectivity Of Depressional Wetlands, Brian P. Neff, Donald O. Rosenberry, Scott G. Leibowitz, Dave M. Mushet, Heather E. Golden, Mark C. Rains, J. R. Brooks, Charles R. Lane Jan 2020

A Hydrologic Landscapes Perspective On Groundwater Connectivity Of Depressional Wetlands, Brian P. Neff, Donald O. Rosenberry, Scott G. Leibowitz, Dave M. Mushet, Heather E. Golden, Mark C. Rains, J. R. Brooks, Charles R. Lane

School of Geosciences Faculty and Staff Publications

Research into processes governing the hydrologic connectivity of depressional wetlands has advanced rapidly in recent years. Nevertheless, a need persists for broadly applicable, non-site-specific guidance to facilitate further research. Here, we explicitly use the hydrologic landscapes theoretical framework to develop broadly applicable conceptual knowledge of depressional-wetland hydrologic connectivity. We used a numerical model to simulate the groundwater flow through five generic hydrologic landscapes. Next, we inserted depressional wetlands into the generic landscapes and repeated the modeling exercise. The results strongly characterize groundwater connectivity from uplands to lowlands as being predominantly indirect. Groundwater flowed from uplands and most of it was …


Tf1.4 Seasonal Floodplain Marshes, D. A. Keith, R. T. Kingsford, R. Mac Nally, B. J. Robson, C. A. Catford, Mark C. Rains, K. Irvine, K. M. Rodriguez-Clark, A. Etter Jan 2020

Tf1.4 Seasonal Floodplain Marshes, D. A. Keith, R. T. Kingsford, R. Mac Nally, B. J. Robson, C. A. Catford, Mark C. Rains, K. Irvine, K. M. Rodriguez-Clark, A. Etter

School of Geosciences Faculty and Staff Publications

No abstract provided.


Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace Nov 2019

Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace

USF Tampa Graduate Theses and Dissertations

The present research examined the viability and utility of eye lenses as a source of lifetime stable-isotope records in fish. It is presented in three sections. The first section compared bulk isotopic variation (bulk analysis) within fish eye-lenses at two temporal resolutions and compared patterns obtained from left and right eyes. The first temporal resolution was lower in an attempt to expose broad-scale isotopic changes during life while reducing effort and cost. This approach did reveal lifetime patterns, but tended to miss certain life events, particularly during early life. The second resolution was higher and provided detail that was missed …


The Peculiar Nature Of Florida’S Sandhill Wetlands, Ponds & Lakes— Their Ecohydrology, Relationship With The Regional Aquifer & Importance Within The Landscape., Renae Starr Nowicki Nov 2019

The Peculiar Nature Of Florida’S Sandhill Wetlands, Ponds & Lakes— Their Ecohydrology, Relationship With The Regional Aquifer & Importance Within The Landscape., Renae Starr Nowicki

USF Tampa Graduate Theses and Dissertations

This dissertation explores the ecohydrology of Florida’s peculiar and poorly studied sandhill wetland and water features, particularly those located in west-central Florida. The primary research goals include: compilation and summarization of the available ecohydrologic information for features across Florida; comparison of water level and water geochemistry data between sandhill wetlands and waters and the regional aquifer to provide evidence of regional hydrologic control; and use of geophysical applications to examine the hydraulic connections between sandhill wetlands and waters and the regional aquifer.

From this research, a natural history of sandhill wetland and water ecohydrology is presented, highlighting: the differences between …


Effects Of Reservoir Conditions And Trace Co-Contaminant Gases On Geological Carbon Sequestration, Ram Kumar Nov 2019

Effects Of Reservoir Conditions And Trace Co-Contaminant Gases On Geological Carbon Sequestration, Ram Kumar

USF Tampa Graduate Theses and Dissertations

Geological carbon sequestration in a saline formation is a promising technology for large-scale carbon dioxide (CO2) mitigation. Several factors such as temperature, pressure, salinity, hydraulic conductivity, and mineralogy of a formation affect the CO2 sequestration in saline formations. These factors can vary widely depending upon the type of formation or the degree of heterogeneity within a formation. In addition to these properties of the repositories, the CO2-rich flue gas streams captured from point sources often contains small amounts of impurities such as sulfur oxides (SOx) and nitrogen oxides (NOx), which may have serious implications on the chemistry of the repositories …


Seafloor Geodesy In Shallow Water With Gps On An Anchored Spar Buoy, Surui Xie, Jason Law, Randy Russell, Timothy H. Dixon, Chad Lembke, Rocco Malservisi, Melanie Rodgers, Giovanni Iannaccone, Sergio Guardato, D. F. Naar Nov 2019

Seafloor Geodesy In Shallow Water With Gps On An Anchored Spar Buoy, Surui Xie, Jason Law, Randy Russell, Timothy H. Dixon, Chad Lembke, Rocco Malservisi, Melanie Rodgers, Giovanni Iannaccone, Sergio Guardato, D. F. Naar

School of Geosciences Faculty and Staff Publications

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near‐shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in subduction zones and submerged volcanoes, and certain freshwater applications, such as volcano deformation in caldera‐hosted lakes. We have developed a seafloor geodesy system for this environment based on an anchored spar buoy topped by high‐precision GPS. Orientation of the buoy is measured using a digital compass that provides heading, pitch, and roll information. The combined orientation and GPS tracking data are used to recover …


Boron Variation And The Subducted Sediment Component In The Volcanics From The Bifurcated Portion Of The Lesser Antilles Island Arc (Laia), Ami Margret Ngo Ward Nov 2019

Boron Variation And The Subducted Sediment Component In The Volcanics From The Bifurcated Portion Of The Lesser Antilles Island Arc (Laia), Ami Margret Ngo Ward

USF Tampa Graduate Theses and Dissertations

North of Martinique island the Lesser Antilles volcanic arc bifurcates, creating a double arc. Here volcanic activity has migrated up to 50 km westward with time, resulting in two volcanic lines that are distinct in age. The eastern line, commonly referred to as the old arc, was active from Early Eocene to Mid-Miocene (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., 1988). The western line, commonly referred to as the recent arc, has been active since the late Pliocene, ~6 Ma ago (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., …


On The Ablation Of Meteors And The Implications On Organic Delivery To Earth, Christopher Alan Mehta Oct 2019

On The Ablation Of Meteors And The Implications On Organic Delivery To Earth, Christopher Alan Mehta

USF Tampa Graduate Theses and Dissertations

The synthesis of prebiotic organic compounds is a key step in the origin of life. Sources of these materials are divided into endogenous and exogenous sources. Endogenous synthesis—occurring potentially on the surface of the Earth—includes such historic experiments as the Miller spark discharge and formose chemistry. However, one avenue for exogenous synthesis to occur is when meteors enters an atmosphere. Using principles of orbital mechanics, geology, physics, and chemistry, we study meteor ablation and the transport of organic matter to the surface of Earth. To do so, I create numerical models that simulates meteors traveling through the atmosphere of Earth …


Mattes J., 2019. Wissenskulturen Des Subterranen. Vermittler Im Spannungsfeld Zwischen Wissenschaft Und Öffentlichkeit. Ein Biographisches Lexikon. [The Culture Of Subterranean Knowledge. Mediators In The Field Of Tension Between Science And Public. A Biographical Lexicon], Monika Schöner Oct 2019

Mattes J., 2019. Wissenskulturen Des Subterranen. Vermittler Im Spannungsfeld Zwischen Wissenschaft Und Öffentlichkeit. Ein Biographisches Lexikon. [The Culture Of Subterranean Knowledge. Mediators In The Field Of Tension Between Science And Public. A Biographical Lexicon], Monika Schöner

International Journal of Speleology

No abstract provided.


The Lampenflora In Show Caves And Its Treatment: An Emerging Ecological Problem, Carlos Baquedano Estévez, Luis Moreno Merino, Almudena De La Losa Román, Juan J. Durán Valsero Oct 2019

The Lampenflora In Show Caves And Its Treatment: An Emerging Ecological Problem, Carlos Baquedano Estévez, Luis Moreno Merino, Almudena De La Losa Román, Juan J. Durán Valsero

International Journal of Speleology

The artificial lighting of caves adapted for touristic visits, leads to the appearance and propagation of a complex community of phototrophic organisms known as “lampenflora”. Formed mainly by algae and cyanobacteria, they produce the degradation of the colonized substrates and decrease the show value of the caves. This phenomenon became famous worldwide in the 1960s due to the damage caused to the paintings in the Lascaux Cave (France). Since then it has become an issue of serious concern to both managers of show caves and to the international scientific community. Over time, the problem has been approached following two complementary …


Barite Replacement Boxwork In The Frasassi Caves (Italy), Sandro Galdenzi Sep 2019

Barite Replacement Boxwork In The Frasassi Caves (Italy), Sandro Galdenzi

International Journal of Speleology

The Frasassi caves, located in the Sentino River Gorge in Ancona Province (Marche, Italy), contains boxwork in a small zone in the inner part of the cave system where it is closely associated with subaqueous corrosion produced by sulfuric acid speleogenesis. The boxwork consists of barite that replaces calcite spar-filled veins and limestone porosity and projects from the corroded cave walls. The replacement involved only the calcite that protrudes from the rock surfaces, indicating that the process took place in the cave environment, and therefore the boxwork is not simply a product of differential corrosion. I hypothesize that the boxwork …


Petrography And Provenance Of Floor Sediments From The Loutra Almopias Cave (Pella, Macedonia, Greece), Ioannis Georgiadis, Katerina Chatzopoulou, Nikolaos Kantiranis, Ioakeim Ioakeimidis, Ananias Tsirambides Sep 2019

Petrography And Provenance Of Floor Sediments From The Loutra Almopias Cave (Pella, Macedonia, Greece), Ioannis Georgiadis, Katerina Chatzopoulou, Nikolaos Kantiranis, Ioakeim Ioakeimidis, Ananias Tsirambides

International Journal of Speleology

Thirty seven floor sediment samples of Upper Pleistocene age from the Loutra Almopias Cave were collected from different beds and stratigraphic columns on the basis of their induration grade, grain distribution, and paleontological findings. Channel facies make up the bulk of the clastic sediments found in the cave passages. Slackwater facies compose the final layer of all the stratigraphic sections of the examined cave. The floor sediments are mineralogically immature, since they contain many ferromagnesian minerals, feldspars (especially plagioclase) and quartz. The extensive presence of silicate minerals means that the phyllites, gneisses, schists, ophiolitic rocks and the clastic Mariam Formation …


Genesis Of Iron And Manganese Sediments In Zoloushka Cave (Ukraine/Moldova) As Revealed By Δ13C Organic Carbon, Piotr Kotula, Viacheslav Andreychouk, Jacek Pawlyta, Leszek Marynowski, Izabela Jendrzejewska Sep 2019

Genesis Of Iron And Manganese Sediments In Zoloushka Cave (Ukraine/Moldova) As Revealed By Δ13C Organic Carbon, Piotr Kotula, Viacheslav Andreychouk, Jacek Pawlyta, Leszek Marynowski, Izabela Jendrzejewska

International Journal of Speleology

Zoloushka Cave is one of the largest maze gypsum caves in the world. Mining of the gypsum bedrock and lowering of the water level due to the pumping of groundwater led to exposure of the cave passages to vadose conditions and changed the hydrochemistry of the karst water. As a result, large quantities of Fe and Mn hydroxides were deposited in the passages. It was found that at least two groups of various organisms were involved in depositing ferrous and manganese sediments. In order to establish the mechanism of deposition, we conducted chemical analyses of the sediments and isotopic analyses …


Full Issue 48(2) Sep 2019

Full Issue 48(2)

International Journal of Speleology

No abstract provided.


Table Of Contents Sep 2019

Table Of Contents

International Journal of Speleology

No abstract provided.


Multi-Phased Hypogene Speleogenesis In A Marginal Horst Structure Of The Malé Karpaty Mountains, Slovakia, Pavel Bella, Pavel Bosák, Petr Mikysek, Juraj Littva, Helena Hercman, Jacek Pawlak Aug 2019

Multi-Phased Hypogene Speleogenesis In A Marginal Horst Structure Of The Malé Karpaty Mountains, Slovakia, Pavel Bella, Pavel Bosák, Petr Mikysek, Juraj Littva, Helena Hercman, Jacek Pawlak

International Journal of Speleology

The Plavecká jaskyňa Cave on the western fault edge of the Malé Karpaty Mountains (western Slovakia) is a result of multi-phased hypogene speleogenesis. It formed in fractured Triassic carbonates by waters ascending along the Vienna Basin Transform Fault between Malé Karpaty Mountains and Záhorská nížina Lowland (the north-eastern part of the Vienna Basin) and/or the N–S-trending faults that intersect it in the cave vicinity. Morphologically, the cave is featured by (1) phreatic chimneys, cupolas, ceiling pockets, enlarged fissures with spongework cavities, upward wall channels and upward oriented large scallops, (2) epiphreatic flat corrosion bedrock floors, feeding fissures and wall water-table …


Fluid-Mobile Trace Element Variability Of Serpentinites And Entrained Crustal Rocks Across The Mariana Forearc System, Raymond M. Johnston Aug 2019

Fluid-Mobile Trace Element Variability Of Serpentinites And Entrained Crustal Rocks Across The Mariana Forearc System, Raymond M. Johnston

USF Tampa Graduate Theses and Dissertations

In the Mariana subduction system, active serpentinite mud volcanoes are associated with the subduction of the Pacific plate beneath the Philippine plate in a non-accretionary convergent plate margin. This location offers a unique opportunity to study the subduction zone interface with little crustal contamination. The systematics of fluid-mobile trace elements (FME) (As, Cs, Rb, Sb, Tl, Pb, and Sr) in erupted serpentinite muds and entrained serpentinized ultramafic and mafic clasts can place constraints on the release of slab-derived fluids from the downgoing plate, and ultimately the pressure/temperature (P/TC°) conditions at which these fluids are mobilized.

The samples analyzed in this …


The Record‐Setting 2018 Eastern North Pacific Hurricane Season, Kimberly M. Wood, Philip J. Klotzbach, Jennifer M. Collins, Carl J. Schreck Aug 2019

The Record‐Setting 2018 Eastern North Pacific Hurricane Season, Kimberly M. Wood, Philip J. Klotzbach, Jennifer M. Collins, Carl J. Schreck

School of Geosciences Faculty and Staff Publications

The extremely active 2018 eastern North Pacific (ENP) hurricane season set records for number of hurricane days, major hurricane days, and accumulated cyclone energy (ACE). The Western Development Region (116°W–180°) was especially active, shattering its prior record for ACE set in 2015. In addition, Hawaii was impacted by Hurricane Lane in August and Tropical Storm Olivia in September. Despite above‐normal sea surface temperatures (SSTs) and below‐normal vertical wind shear in 2018, large‐scale conditions were generally less conducive for tropical cyclone (TC) formation than in 2015. However, the strong subtropical ridge in August and September of 2018 enhanced westward steering flow, …


Breakdown Mechanisms In Iron Caves. An Example From Brazil, Marcelo R. Barbosa, Allan D.F. Da Silva, Rafael G. De Paula, Georgete M. Dutra, Airton Barata, Iuri V. Brandi, Chrystophe R.P. Da Silva, Robert A. Osborne Jul 2019

Breakdown Mechanisms In Iron Caves. An Example From Brazil, Marcelo R. Barbosa, Allan D.F. Da Silva, Rafael G. De Paula, Georgete M. Dutra, Airton Barata, Iuri V. Brandi, Chrystophe R.P. Da Silva, Robert A. Osborne

International Journal of Speleology

An iron cave in the vicinity of a mine in Carajás, Brazil, was selected to be mined within an assisted elimination project, planned to control all mine advancement operations towards the cave along with a strict speleological physical monitoring. It allowed, in a pioneering way, the recording of events in the cave from the first signs of damage until to the total collapse of the cave. The project lasted four years and it was possible to identify and describe four breakdown mechanisms in iron caves: Fragment downfall, Block downfall, Controlling structure reactivation, and Open discontinuity movement. The mechanisms occurred independently …


Stable Isotope Geochemistry Of Shelled Marine Invertebrates: Wide-Ranging Applications, Nasser M. Al-Qattan Jul 2019

Stable Isotope Geochemistry Of Shelled Marine Invertebrates: Wide-Ranging Applications, Nasser M. Al-Qattan

USF Tampa Graduate Theses and Dissertations

Mollusks grow by adding discrete growth layers throughout their lifetime (i.e., accretion). More specifically, most marine mollusks precipitate their shells in oxygen isotopic equilibrium with seawater or with a constant offset from equilibrium. The stable oxygen isotope values (δ18O) of their shells are determined by the temperature and δ18O values of the surrounding water during calcification without significant vital effects. In comparison, the stable carbon isotope values (δ13C) of their shells reflect those of the dissolved inorganic carbon (δ13C- DIC) and respired carbon dioxide. Therefore, variations in the oxygen and carbon isotope …