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Articles 511 - 540 of 1880

Full-Text Articles in Earth Sciences

The Morphology And Development Of Kalahroud Cave, Iran, Shirin Bahadorinia, Sayed Hassan Hejazi, Alireza Nadimi, Derek C. Ford, Karine Wainer Oct 2016

The Morphology And Development Of Kalahroud Cave, Iran, Shirin Bahadorinia, Sayed Hassan Hejazi, Alireza Nadimi, Derek C. Ford, Karine Wainer

International Journal of Speleology

Kalahroud Cave is located in central Iran, ~50 km north of Isfahan. The landscape is a typical mountain desert morphology of cuestas dissected by ravines and gorges created during rare surface run-off events; crest lines are ~2800 m asl and lowlands at ~2100 m asl. Kalahroud Cave (4500 m of mapped passages, ~60 m deep) is entered through breakdown in the eastern wall of a gorge. The host rock is a Cretaceous limestone and mudstone formation 60 m in thickness, underlain by sandstones and conglomerates and overlain by weakly permeable calcareous marl strata, all dipping 15-20o. Below the …


Poster Madness, Jennifer Collins Oct 2016

Poster Madness, Jennifer Collins

School of Geosciences Faculty and Staff Publications

No abstract provided.


The Geophysical Kitchen Sink Approach To Improving Our Understanding Of Volcano-Tectonic Interactions, Ophelia Ann George Sep 2016

The Geophysical Kitchen Sink Approach To Improving Our Understanding Of Volcano-Tectonic Interactions, Ophelia Ann George

USF Tampa Graduate Theses and Dissertations

A multi-prong approach was taken in this dissertation to understand volcanic processes from both a long-term and more immediate hazard perspective. In the long-term, magma sources within the crust may produce measurable surficial response and long-wavelength gravity anomalies that provide information about the extent and depth of this magma. Long-term volcanic hazard forecasting is also improved by developing as complete a record as possible of past events. In the short-term, a long-standing question has been on the casting of precursory volcanic activity in terms of future volcanic hazards. Three studies are presented in this dissertation to address these issues. Inversion …


The Record‐Breaking 2015 Hurricane Season In The Eastern North Pacific: An Analysis Of Environmental Conditions, Jennifer Collins, Philip J. Klotzbach, Ryan N. Maue, David R. Roache, Eric S. Blake, Charles H. Paxton, Christopher A. Mehta Sep 2016

The Record‐Breaking 2015 Hurricane Season In The Eastern North Pacific: An Analysis Of Environmental Conditions, Jennifer Collins, Philip J. Klotzbach, Ryan N. Maue, David R. Roache, Eric S. Blake, Charles H. Paxton, Christopher A. Mehta

School of Geosciences Faculty and Staff Publications

The presence of a near‐record El Niño and a positive Pacific Meridional Mode provided an extraordinarily warm background state that fueled the 2015 eastern North Pacific hurricane season to near‐record levels. We find that the western portion of the eastern North Pacific, referred to as the Western Development Region (WDR; 10°–20°N, 116°W–180°), set records for named storms, hurricane days, and Accumulated Cyclone Energy in 2015. When analyzing large‐scale environmental conditions, we show that record warm sea surface temperatures, high midlevel relative humidity, high low‐level relative vorticity, and record low vertical wind shear were among the environmental forcing factors contributing to …


High-Resolution Signatures Of Oxygenation And Microbiological Activity In Speleothem Fluid Inclusions, Nigel Blamey, Penelope J. Boston, Laura Rosales-Lagarde Aug 2016

High-Resolution Signatures Of Oxygenation And Microbiological Activity In Speleothem Fluid Inclusions, Nigel Blamey, Penelope J. Boston, Laura Rosales-Lagarde

International Journal of Speleology

Speleothems frequently host “fossil” fluids that were trapped in small inclusions during growth. Such fluids may provide valuable clues to past microbial, geochemical, and climatic processes during their formation. However, one difficulty is to understand which gases represent background atmosphere and fluids within a given cave system at a particular time, and which may be the product of post-trapping residual microbial activity or abiotic chemical reactions? Do we have any hope of sorting out these differences? The success depends on a quantitative understanding of the gas composition trapped in the inclusions and an understanding of the interactions of cave mineralogy, …


Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo Aug 2016

Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo

International Journal of Speleology

Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence and bifurcation process are re-constructed by interpretation of tube floor continuity, the distribution of remnant tubes and the scales of lava tube branches (shapes of …


Tephraprob: A Matlab Package For Probabilistic Hazard Assessments Of Tephra Fallout, Sébastien Biass, Costanza Bonadonna, Laura J. Connor, Charles B. Connor Aug 2016

Tephraprob: A Matlab Package For Probabilistic Hazard Assessments Of Tephra Fallout, Sébastien Biass, Costanza Bonadonna, Laura J. Connor, Charles B. Connor

School of Geosciences Faculty and Staff Publications

TephraProb is a toolbox of Matlab functions designed to produce scenario–based probabilistic hazard assessments for ground tephra accumulation based on the Tephra2 model. The toolbox includes a series of graphical user interfaces that collect, analyze and pre–process input data, create distributions of eruption source parameters based on a wide range of probabilistic eruption scenarios, run Tephra2 using the generated input scenarios and provide results as exceedence probability maps, probabilistic isomass maps and hazard curves. We illustrate the functionality of TephraProb using the 2011 eruption of Cordón Caulle volcano (Chile) and selected eruptions of La Fossa volcano (Vulcano Island, Italy). The …


Transitions Between Explosive And Effusive Phases During The Cataclysmic 2010 Eruption Of Merapi Volcano, Java, Indonesia, Katie Preece, Ralf Gertisser, Jenni Barclay, Sylvain J. Charbonnier, Jean-Christophe Komorowski, Richard A. Herd Aug 2016

Transitions Between Explosive And Effusive Phases During The Cataclysmic 2010 Eruption Of Merapi Volcano, Java, Indonesia, Katie Preece, Ralf Gertisser, Jenni Barclay, Sylvain J. Charbonnier, Jean-Christophe Komorowski, Richard A. Herd

School of Geosciences Faculty and Staff Publications

Transitions between explosive and effusive activity are commonly observed during dome-forming eruptions and may be linked to factors such as magma influx, ascent rate and degassing. However, the interplay between these factors is complex and the resulting eruptive behaviour often unpredictable. This paper focuses on the driving forces behind the explosive and effusive activity during the well-documented 2010 eruption of Merapi, the volcano’s largest eruption since 1872. Time-controlled samples were collected from the 2010 deposits, linked to eruption stage and style of activity. These include scoria and pumice from the initial explosions, dense and scoriaceous dome samples formed via effusive …


A Molluscan Record Of Monsoonal Precipitation Along The Western Shoreline Of The Late Maastrichtian Western Interior Seaway, Scott Allen Ishler Jul 2016

A Molluscan Record Of Monsoonal Precipitation Along The Western Shoreline Of The Late Maastrichtian Western Interior Seaway, Scott Allen Ishler

USF Tampa Graduate Theses and Dissertations

Global warming in response to increasing levels of atmospheric CO2 concentration (pCO2) has generated concern over the effects of increasing surface temperature on the hydrologic cycle. Investigating precipitation dynamics during past ‘greenhouse’ intervals provide important insights necessary to better constrain potential future climate scenarios. The Late Cretaceous greenhouse is characterized by elevated pCO2 and surface temperatures, with a prolonged cooling trend which initiated in the late Campanian and an associated 4th-order sea-level regression recorded in the Western Interior Seaway (WIS), providing an opportunity to examine the hydrologic cycle under conditions of changing temperature and sea-level. …


On A Desert Island With Unit Sticks, Continued Fractions And Lagrange, Victor J. Ricchezza, H. L. Vacher Jul 2016

On A Desert Island With Unit Sticks, Continued Fractions And Lagrange, Victor J. Ricchezza, H. L. Vacher

Numeracy

GLY 4866, Computational Geology, provides an opportunity, welcomed by our faculty, to teach quantitative literacy to geology majors at USF. The course continues to evolve although the second author has been teaching it for some 20 years. This paper describes our experiences with a new lab activity that we are developing on the core issue of measurement and units. The activity is inspired by a passage in the 2008 publication of lectures that Joseph Louis Lagrange delivered at the Ecole Normale in 1795. The activity envisions that young scientists are faced with the need to determine the dimensions of a …


Optimizing Methods For Extraction Of Organic Compounds From Molluscan Shells, Kaydee Jo West Jun 2016

Optimizing Methods For Extraction Of Organic Compounds From Molluscan Shells, Kaydee Jo West

USF Tampa Graduate Theses and Dissertations

Mollusk shells contain proteins within and between the crystals of calcium carbonate. These organic molecules play an important role in biomineralization and shell function, and their stable isotope ratios of carbon and nitrogen are also thought to record important ecological information about the animal's diet and nutrient sources. These proteins can be preserved for millions of years, offering potential insight into pre-anthropogenic ecological conditions. However, shell organics in older shells are typically recovered in reduced abundances due to leaching and remaining organics are often converted from insoluble proteins to soluble, free amino acids, making them difficult to detect and recover. …


Development And Validation Of A Remote Sensing Model To Identify Anthropogenic Boreholes That Provide Dry Season, Refuge Habitat For Anopheles Vector Mosquitoes In Sub-Saharan Africa, James Pkemoi Kukat Jun 2016

Development And Validation Of A Remote Sensing Model To Identify Anthropogenic Boreholes That Provide Dry Season, Refuge Habitat For Anopheles Vector Mosquitoes In Sub-Saharan Africa, James Pkemoi Kukat

USF Tampa Graduate Theses and Dissertations

A lack of surveillance systems is an impediment to public health intervention for perennial vector-borne disease transmission in northern tropical savanna region of Kenya. The population in this area are mostly poor nomadic pastoralists with little acquired functional immunity to Plasmodium falciparum, due to infrequent challenges with the parasite. A common characteristic in tropical savanna climatic zone is the availability of riverbeds that have anthropogenic boreholes that provide malaria vector mosquitoes, such as Anopheles gambiae s.l and Anopheles funestus, with aquatic refuge habitats for proliferation and endemic transmission to proximity human households during the dry-season. Unfortunately, currently there …


Pollutants And Foraminiferal Assemblages In Torrecillas Lagoon: An Environmental Micropaleontology Approach, Michael Martinez-Colon Jun 2016

Pollutants And Foraminiferal Assemblages In Torrecillas Lagoon: An Environmental Micropaleontology Approach, Michael Martinez-Colon

USF Tampa Graduate Theses and Dissertations

Torrecillas Lagoon in the North Coast of Puerto Rico has experienced extensive anthropogenic influence over the past 400 years. Elevated concentrations of Potential Toxic Elements (PTEs) have been reported in surficial sediments. The main goal of this dissertation was to implement in Puerto Rico the use of benthic foraminifers as a bioindicators of PTEs and to compare the impact of Cu(II) on field samples with results of experimental work using cultures.

Analyses included geochemical assessment for bulk and carbonate- soluble bioavailable concentrations of PTEs in surface, core and pore-water samples, as well as analyses of grain-size, Percent Total Organic Carbon …


Alumni Narratives On Computational Geology (Spring 1997 – Fall 2013), Victor J. Ricchezza Jun 2016

Alumni Narratives On Computational Geology (Spring 1997 – Fall 2013), Victor J. Ricchezza

USF Tampa Graduate Theses and Dissertations

Recent meetings and publications have discussed what geoscience undergraduates should learn for professional success, and among other items, have identified several quantitative skills and habits of mind as being necessary for geoscience students; many of these items are commonly associated with Quantitative Literacy (QL). The Computational Geology course in the geology department has been evolving at USF for 20 years. The course teaches QL in a geologic setting independent of specific core geology topics. This course has long preceded the national acknowledgment of the need for what it teaches within the field. As the first of a series of related …


Is Uplift Of Volcano Clusters In The Tohoku Volcanic Arc, Japan, Driven By Magma Accumulation In Hot Zones? A Geodynamic Modeling Study, Ophelia A. George, Rocco Malservisi, Rob Govers, Charles B. Connor, Laura J. Connor Jun 2016

Is Uplift Of Volcano Clusters In The Tohoku Volcanic Arc, Japan, Driven By Magma Accumulation In Hot Zones? A Geodynamic Modeling Study, Ophelia A. George, Rocco Malservisi, Rob Govers, Charles B. Connor, Laura J. Connor

School of Geosciences Faculty and Staff Publications

In many volcanic arcs, the rate of tectonic uplift cannot be explained by lithospheric plate motion alone but may be associated with dynamic uplift. Buoyant forces associated with underplated magma bodies lift the upper crust and leads to relatively high rates of topographic change. One such region is northern Honshu, Japan, where Quaternary volcano clusters are spatially associated with uplifted crust and isostatic gravity anomalies. Axisymmetric inversion of Bouguer gravity data for the Sengan volcano cluster shows that these gravity anomalies can be modeled by 30 km radius bodies emplaced at ∼15 km depth. Axisymmetric, finite element models, generated using …


Applications Of Satellite Geodesy In Environmental And Climate Change, Qian Yang May 2016

Applications Of Satellite Geodesy In Environmental And Climate Change, Qian Yang

USF Tampa Graduate Theses and Dissertations

Satellite geodesy plays an important role in earth observation. This dissertation presents three applications of satellite geodesy in environmental and climate change. Three satellite geodesy techniques are used: high-precision Global Positioning System (GPS), the Gravity Recovery and Climate Experiment (GRACE) and Interferometric Synthetic Aperture Radar (InSAR). In the first study, I use coastal uplift observed by GPS to study the annual changes in mass loss of the Greenland ice sheet. The data show both spatial and temporal variations of coastal ice mass loss and suggest that a combination of warm atmospheric and oceanic condition drove these variations. In the second …


Search For An Artificially Buried Karst Cave Entrance Using Ground Penetrating Radar: A Successful Case Of Locating The S-19 Cave In The Mt. Kanin Massif (Nw Slovenia), Andrej Gosar, Teja Čeru May 2016

Search For An Artificially Buried Karst Cave Entrance Using Ground Penetrating Radar: A Successful Case Of Locating The S-19 Cave In The Mt. Kanin Massif (Nw Slovenia), Andrej Gosar, Teja Čeru

International Journal of Speleology

The S-19 Cave was with its explored depth of 177 m one of the most important caves of the Mt. Kanin massif, but after its discovery in 1974, a huge snow avalanche protection dyke was constructed across the cave entrance. To excavate the buried cave, the accurate location of the cave had to be determined first. Since the entrance coordinates were incorrect and no markers were available, application of geophysical techniques was necessary to do this. A Ground Penetrating Radar (GPR) with special 50 MHz rough terrain antennas was selected as the single suitable geophysical method for the given conditions …


Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu May 2016

Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu

International Journal of Speleology

The most common methods used for assessing the relative age of a cave bear bone assemblage are the P4/4 index (morphodynamic index of the cave bear fourth premolar), the K-index and the Index of Plumpness (both used for cave bear’s 2nd metatarsal). Preliminary work on this (Robu et al., 2011), for Urşilor Cave (NW Romania), has indicated one of the youngest European cave bear populations. As the number of extracted fossil bones from the palaeontological excavation increased recently, a re-assessment of the of the age of the cave bear assemblage is necessary. 206 cave bear fourth …


Morphodynamics Of Egmont Key At The Mouth Of Tampa Bay: West-Central Florida, Zachary James Tyler Apr 2016

Morphodynamics Of Egmont Key At The Mouth Of Tampa Bay: West-Central Florida, Zachary James Tyler

USF Tampa Graduate Theses and Dissertations

Egmont Key, located at the mouth of Tampa Bay, is part of a dynamic system with many interrelated natural and anthropogenic factors influencing its morphodynamics. This study started in August 2012. During the 3-year period until August 2015, 28 beach profile transects were established and surveyed 10 times. Seventeen historical aerial images from 1942 to 2013 were geo-rectified and analyzed. Three hundred and fourteen sediment samples were procured from the navigation channel dredge area and the beach nourishment area and analyzed for grain size. A numerical wave model was established to simulate the nearshore wave field. The overall goals of …


Subsidence Along The Atlantic Coast Of North America: Insights From Gps And Late Holocene Relative Sea Level Data, Makan A. Karegar, Timothy H. Dixon, Simon E. Engelhart Apr 2016

Subsidence Along The Atlantic Coast Of North America: Insights From Gps And Late Holocene Relative Sea Level Data, Makan A. Karegar, Timothy H. Dixon, Simon E. Engelhart

School of Geosciences Faculty and Staff Publications

The Atlantic Coast of North America is increasingly affected by flooding associated with tropical and extratropical storms, exacerbated by the combined effects of accelerated sea‐level rise and land subsidence. The region includes the collapsing forebulge of the Laurentide Ice Sheet. High‐quality records of late Holocene relative sea‐level (RSL) rise are now available, allowing separation of long‐term glacial isostatic adjustment‐induced displacement from modern vertical displacement measured by GPS. We compare geological records of late Holocene RSL to present‐day vertical rates from GPS. For many coastal areas there is no significant difference between these independent data. Exceptions occur in areas of recent …


Hercules And Diana Hypogene Caves (Herculane Spa, Romania): Dissimilar Chemical Evolutions Documented By Their Present-Day Thermal Water Discharges, Horia Mitrofan, Constantin Marin, Ioan Povară, Bogdan P. Onac Apr 2016

Hercules And Diana Hypogene Caves (Herculane Spa, Romania): Dissimilar Chemical Evolutions Documented By Their Present-Day Thermal Water Discharges, Horia Mitrofan, Constantin Marin, Ioan Povară, Bogdan P. Onac

School of Geosciences Faculty and Staff Publications

Hercules Cave and Diana Cave are two small caves situated some 600 m apart, for which a hypogene origin has been previously suggested. Thermal water discharges (up to about 54°C) are hosted by each cave, and were recently made the object of an eight-month chemical monitoring operation. By plotting the concentrations of several chemical species (Na, K, Ca, Sr, Mg, SiO2, Br) against the concentration of the conservative anion Cl, it was found that both caves discharged a binary water mixture, which was derived from the same saline (and hot) parent-fluid and the same fresh (and cold) parent-fluid. This fact …


A New Volcanic Event Recurrence Rate Model And Code For Estimating Uncertainty In Recurrence Rate And Volume Flux Through Time With Selected Examples, James Adams Wilson Mar 2016

A New Volcanic Event Recurrence Rate Model And Code For Estimating Uncertainty In Recurrence Rate And Volume Flux Through Time With Selected Examples, James Adams Wilson

USF Tampa Graduate Theses and Dissertations

Recurrence rate is often used to describe volcanic activity. There are numerous documented ex- amples of non-constant recurrence rate (e.g. Dohrenwend et al., 1984; Condit and Connor, 1996; Cronin et al., 2001; Bebbington and Cronin, 2011; Bevilacqua, 2015), but current techniques for calculating recurrence rate are unable to fully account for temporal changes in recurrence rate. A local–window recurrence rate model, which allows for non-constant recurrence rate, is used to calculate recurrence rate from an age model consisting of estimated ages of volcanic eruption from a Monte Carlo simulation. The Monte Carlo age assignment algorithm utilizes paleomagnetic and stratigraphic information …


Modeling The Construction And Evolution Of Distributed Volcanic Fields On Earth And Mars, Jacob Armstrong Richardson Mar 2016

Modeling The Construction And Evolution Of Distributed Volcanic Fields On Earth And Mars, Jacob Armstrong Richardson

USF Tampa Graduate Theses and Dissertations

Magmatism is a dominant process on Earth and Mars that has significantly modified and evolved the lithospheres of each planet by delivering magma to shallow depths and to the surface. Two common modes of volcanism are present on both Earth and Mars: central-vent dominated volcanism that creates large edifices from concentrating magma in chambers before eruptions and distributed volcanism that creates many smaller edifices on the surface through the independent ascent of individual magmatic dikes. In regions of distributed volcanism, clusters of volcanoes develop over thousands to millions of years. This dissertation explores the geology of distributed volcanism on Earth …


U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom Feb 2016

U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom

International Journal of Speleology

The 1100-meter Big Room elevation level of Carlsbad Cavern, New Mexico USA, formed 4 Ma by hypogenic sulfuric acid speleogenesis (SAS). The age of the Big Room level of 4.0 ± 0.2 Ma was previously determined by dating alunite, a byproduct of speleogenesis, using the 40Ar/39Ar method. Duplication of these results is possible by radiometric dating of other byproducts interpreted to be speleogenetic (a byproduct of speleogenesis) such as calcite and dolomite in certain settings. XRD and TEM analyses of sample 94044, a piece of crust collected within the Big Room level of SAS just below Left …


Ultra‐Long‐Range Hydroacoustic Observations Of Submarine Volcanic Activity At Monowai, Kermadec Arc, D. Metz, A. B. Watts, I. Grevemeyer, Mel Rodgers, M. Paulatto Feb 2016

Ultra‐Long‐Range Hydroacoustic Observations Of Submarine Volcanic Activity At Monowai, Kermadec Arc, D. Metz, A. B. Watts, I. Grevemeyer, Mel Rodgers, M. Paulatto

School of Geosciences Faculty and Staff Publications

Monowai is an active submarine volcanic center in the Kermadec Arc, Southwest Pacific Ocean. During May 2011, it erupted over a period of 5 days, with explosive activity directly linked to the generation of seismoacoustic T phases. We show, using cross‐correlation and time‐difference‐of‐arrival techniques, that the eruption is detected as far as Ascension Island, equatorial South Atlantic Ocean, where a bottom moored hydrophone array is operated as part of the International Monitoring System of the Comprehensive Nuclear‐Test‐Ban Treaty Organization. Hydroacoustic phases from the volcanic center must therefore have propagated through the Sound Fixing and Ranging channel in the South Pacific …


A Decade Of Modern Cave Surveying With Terrestrial Laser Scanning: A Review Of Sensors, Method And Application Development, Idrees Mohammed Oludare, Biswajeet Pradhan Jan 2016

A Decade Of Modern Cave Surveying With Terrestrial Laser Scanning: A Review Of Sensors, Method And Application Development, Idrees Mohammed Oludare, Biswajeet Pradhan

International Journal of Speleology

During the last decade, the need to survey and model caves or caverns in their correct three-dimensional geometry has increased due to two major competing motivations. One is the emergence of medium and long range terrestrial laser scanning (TLS) technology that can collect high point density with unprecedented accuracy and speed, and two, the expanding sphere of multidisciplinary research in understanding the origin and development of cave, called speleogenesis. Accurate surveying of caves has always been fundamental to understanding their origin and processes that lead to their current state and as well provide tools and information to predict future. Several …


Effects Of Nutrient Supplementation On Host-Pathogen Dynamics Of The Amphibian Chytrid Fungus: A Community Approach, Julia C. Buck, Jason R. Rohr, Andrew R. Blaustein Jan 2016

Effects Of Nutrient Supplementation On Host-Pathogen Dynamics Of The Amphibian Chytrid Fungus: A Community Approach, Julia C. Buck, Jason R. Rohr, Andrew R. Blaustein

Integrative Biology Faculty and Staff Publications

  1. Anthropogenic stressors may influence hosts and their pathogens directly or may alter host–pathogen dynamics indirectly through interactions with other species. For example, in aquatic ecosystems, eutrophication may be associated with increased or decreased disease risk. Conversely, pathogens can influence community structure and function and are increasingly recognised as important members of the ecological communities in which they exist.
  2. In outdoor mesocosms, we experimentally manipulated nutrients (nitrogen and phosphorus) and the presence of a fungal pathogen, Batrachochytrium dendrobatidis (Bd), and examined the effects on Bd abundance on larval amphibian hosts (Pseudacris regilla: Hylidae), amphibian traits and community dynamics. We …


Recent Increases In Arctic Freshwater Flux Affects Labrador Sea Convection And Atlantic Overturning Circulation, Qian Yang, Tim Dixon, Paul G. Myers, Jennifer Bonin, Don Chambers, M.R. Van Den Broeke, Mads H. Ribergaard, John Mortensen Jan 2016

Recent Increases In Arctic Freshwater Flux Affects Labrador Sea Convection And Atlantic Overturning Circulation, Qian Yang, Tim Dixon, Paul G. Myers, Jennifer Bonin, Don Chambers, M.R. Van Den Broeke, Mads H. Ribergaard, John Mortensen

School of Geosciences Faculty and Staff Publications

The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland’s ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from …


Volcanic Lightning In Eruptions Of Sakurajima Volcano, Harald E. Edens, Ronald J. Thomas, Sonja A. Behnke, Stephen R. Mcnutt, Cassandra M. Smith, Alexandra Farrell, Alexa R. Van Eaton, Corrado Cimarelli, Valeria Cigala, Ken Eack, Graydon Aulich, Christopher Michael, Daisuke Miki, Masato Iguchi Jan 2016

Volcanic Lightning In Eruptions Of Sakurajima Volcano, Harald E. Edens, Ronald J. Thomas, Sonja A. Behnke, Stephen R. Mcnutt, Cassandra M. Smith, Alexandra Farrell, Alexa R. Van Eaton, Corrado Cimarelli, Valeria Cigala, Ken Eack, Graydon Aulich, Christopher Michael, Daisuke Miki, Masato Iguchi

School of Geosciences Faculty and Staff Publications

In May 2015 a field program was undertaken to study volcanic lightning at the Sakurajima volcano in southern Japan. One of the main goals of the study was to gain a better understanding of small electrical discharges in volcanic eruptions, expanding on our earlier studies of volcanic lightning at Augustine and Redoubt volcanoes in Alaska, USA, and Eyjafjallajökull in Iceland. In typical volcanic eruptions, electrical activity occurs at the onset of an eruption as a near-continual production of VHF emissions at or near to the volcanic vent. These emissions can occur at rates of up to tens of thousands of …


Encrustation Of Inarticulate Brachiopods On Scaphitid Ammonites And Inoceramid Bivalves From The Upper Cretaceous U. S. Western Interior, Neil H. Landman, Joshua S. Slattery, Peter J. Harries Jan 2016

Encrustation Of Inarticulate Brachiopods On Scaphitid Ammonites And Inoceramid Bivalves From The Upper Cretaceous U. S. Western Interior, Neil H. Landman, Joshua S. Slattery, Peter J. Harries

School of Geosciences Faculty and Staff Publications

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from east-central Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they …