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Full-Text Articles in Geology

Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Mike Marasa Oct 2015

Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Mike Marasa

Sinkhole Conference 2015

On February 12th, 2014, a sinkhole occurred at the National Corvette Museum in Bowling Green, Kentucky. The collapse happened inside part of the building known as the Skydome and eight Corvettes on display were lost into the void that opened in the concrete floor. In this region of Kentucky, known as the Pennyroyal sinkhole plain, subsidence and cover collapse sinkholes are commonly found throughout the landscape. This iconic karst region in the United States is also home to Mammoth Cave, the longest cave in the world, and thousands of other caves and karst features. Investigation of the sinkhole collapse began …


Finding Springs In The File Cabinet, Mason Johnson, Ashley Ignatius Oct 2015

Finding Springs In The File Cabinet, Mason Johnson, Ashley Ignatius

Sinkhole Conference 2015

The Minnesota Pollution Control Agency (MPCA), in partnership with other agencies, is currently undertaking comprehensive sub-basin assessments statewide over a ten-year period. Southeast Minnesota has over 17,500 kilometers of perennial and intermittent streams, making the task of comprehensive sub-basin assessment challenging; the task is further complicated by karst geology. In the summer of 2014, a pilot project began between the MPCA and Minnesota Department of Natural Resources (DNR) to digitally preserve paper documents which capture qualitative and quantitative data about the hydrology, water chemistry, geomorphology, biology, land use and karst features of southeast Minnesota streams. The paper documents in file …


Sinkhole Vulnerability Mapping: Results From A Pilot Study In North Central Florida, Clint Kromhout, Alan E. Baker Oct 2015

Sinkhole Vulnerability Mapping: Results From A Pilot Study In North Central Florida, Clint Kromhout, Alan E. Baker

Sinkhole Conference 2015

At the end of June in 2012, Tropical Storm Debby dropped a record amount of rainfall across Florida which triggered hundreds, if not thousands, of sinkholes to form which resulted in tremendous damage to property. The Florida Division of Emergency Management contracted with the Florida Department of Environmental Protection’s Florida Geological Survey to produce a map depicting the state’s vulnerability to sinkhole formation. The three-year project began with a pilot study in three northern Florida counties: Columbia, Hamilton and Suwannee. Utilizing the statistical modeling method Weights of Evidence, results from the pilot study yielded a 93 percent success rate of …


Creation Of A Map Of Paleozoic Bedrock Springsheds In Southeast Minnesota, Jeffrey A. Green, E. Calvin Alexander Jr. Oct 2015

Creation Of A Map Of Paleozoic Bedrock Springsheds In Southeast Minnesota, Jeffrey A. Green, E. Calvin Alexander Jr.

Sinkhole Conference 2015

Springs are groundwater discharge points that serve as vital coldwater sources for streams in southeast Minnesota. The springs generally emanate from Paleozoic carbonate and siliciclastic bedrock aquifers. Use of systematic dye tracing began in the 1970s and continues through the present as a standard method for investigating karst hydrology and to map springsheds,. The work was accelerated in 2007 because of increased funding from the State of Minnesota’s Environment and Natural Resources Trust Fund. A compilation springshed map of dye traces conducted over the last several decades has been assembled for the region. In southeast Minnesota, the springs are the …


Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea Oct 2015

Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea

Sinkhole Conference 2015

Much of the Driftless Area of southeastern Minnesota is underlain by karstified carbonate bedrock. Land use in this karst terrain is dominated by agriculture, including row crop and dairy operations. The karst in this region is often mantled with up to 15 m of soil and unconsolidated sediments. As a result, underlying karst hazards such as incipient sinkholes are often hidden until they are suddenly revealed by the collapse of subsurface voids. Regionally, the economics of the dairy industry is causing a trend toward the consolidation and expansion of existing operations. As concentrated animal feeding operations (CAFO) or feedlots expand, …


Karst Influence In The Creation Of A Pfc Megaplume, Virginia Yingling Oct 2015

Karst Influence In The Creation Of A Pfc Megaplume, Virginia Yingling

Sinkhole Conference 2015

Perfluorochemicals (PFCs) are fully-fluorinated organic chemicals used to produce a wide range of industrial and commercial products. Their extreme persistence and mobility in the environment and nearly ubiquitous presence in humans and wildlife has raised serious concerns regarding their environmental and human health effects. In the 1940s to 1970s, PFC-bearing wastes were disposed of in three unlined landfills in Washington County, Minnesota. The resulting co-mingled PFC plumes created a “megaplume” that contaminated over 250 km2 of groundwater and four major drinking water aquifers; affecting eight municipal water supply systems and thousands of private wells. Site investigations revealed that karst features, …


Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi Oct 2015

Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi

Sinkhole Conference 2015

Standard groundwater tracers such as Rhodamine WT, Fluorescein, Eosin and Tinopal CBX effectively provide a snapshot of hydrological conditions over a brief period of time and in a tightly controlled setting. However, in complex environmental situations with multiple potential sources, groundwater hydrologists are often seeking groundwater tracers that have extended longevity in the natural environment and the ability to directly pinpoint source locations. After reviewing operations of the nearby dairy it was determined that emerging contaminants, specifically two bovine veterinary pharmaceuticals (antibiotics), cephapirin sodium (CEPNa) and cephapirin benzathine (CEPB), and a sanitation agent, elemental Iodine (I) may have potential as …


Seeps And Springs At A Platteville “Observatory” On The River Bluffs, Bj Bonin, Greg Brick, Julia R. Steenberg Oct 2015

Seeps And Springs At A Platteville “Observatory” On The River Bluffs, Bj Bonin, Greg Brick, Julia R. Steenberg

Sinkhole Conference 2015

Residential building construction along the Mississippi River bluffs in the 1970s created a unique enclosed outcrop of the Late Ordovician Platteville Formation at Lilydale, Minnesota. This outcrop was examined in early 2013 after a newly-formed spring flooded an elevator shaft the previous year, drawing attention to the foundation conditions. The Lexington Riverside property is a six story condominium complex constructed within the top of the bluff. A two-level underground parking garage was built into the bluff. Bedrock was mechanically excavated to accommodate the construction of the building, creating an unweathered rock surface. The space between the structure and the excavated …


Conduit Flow In The Cambrian Lone Rock Formation, Southeast Minnesota, U.S.A., John D. Barry, Jeffrey A. Green, Julia R. Steenberg Oct 2015

Conduit Flow In The Cambrian Lone Rock Formation, Southeast Minnesota, U.S.A., John D. Barry, Jeffrey A. Green, Julia R. Steenberg

Sinkhole Conference 2015

The karst lands of southeast Minnesota contain more than one hundred trout streams that receive perennial discharge from Paleozoic bedrock springs. Several of the Paleozoic bedrock units that provide discharge are karst aquifers. Field investigations into the flow characteristics of these formations have been conducted using fluorescent dyes to map groundwater springsheds and characterize groundwater flow velocities for use in water resource protection. Recent field work has focused on the Cambrian Lone Rock Formation, a siliciclastic unit consisting of very fine-grained sandstone and siltstone with minor beds of shale and dolostone. The formation is mapped within tributary valleys of the …


Tracer Studies Conducted Nearly Two Decades Apart Elucidate Groundwater Movement Through A Karst Aquifer In The Frederick Valley Of Maryland, Keith A. White, Michael K. Cobb, Thomas Aley, Ethan Weikel Oct 2015

Tracer Studies Conducted Nearly Two Decades Apart Elucidate Groundwater Movement Through A Karst Aquifer In The Frederick Valley Of Maryland, Keith A. White, Michael K. Cobb, Thomas Aley, Ethan Weikel

Sinkhole Conference 2015

A pair of groundwater tracer studies at a single karst test site were completed 18 years apart. The results of these studies have provided evidence of both relatively rapid advective transport via conduits and an extreme capacity for dye storage and retardation. The tracer results, coupled with other subsurface investigation data, are used to develop a conceptual model for groundwater movement through this karst aquifer in the Frederick Valley of Maryland, as well as identify implications for remediation. Three fluorescent tracer dyes used in the initial study were detected in several background monitoring locations established for the second study conducted …


Hydrogeological Dynamic Variability In The Lomme Karst System (Belgium) As Evidenced By Tracer Tests Results (Karag Project), Amaël Poulain, Gaëtan Rochez, Vincent Hallet Oct 2015

Hydrogeological Dynamic Variability In The Lomme Karst System (Belgium) As Evidenced By Tracer Tests Results (Karag Project), Amaël Poulain, Gaëtan Rochez, Vincent Hallet

Sinkhole Conference 2015

Paleozoic carbonate aquifers represent major groundwater resources in Belgium. Karstification processes affect most of them and Belgium counts many hydrologically active karst networks. Given the intrinsic vulnerability of such geological objects, comprehensive studies are required in order to improve their protection and management. The KARAG project (Karst Aquifer ReseArch by Geophysic, 2013-2017) aims to identify the specific dynamic of karst aquifers by using geophysical and hydrogeological tools. This research is funded by the Belgium National Fund for Scientific Research (FNRS) and conducted by the University of Namur, University of Mons and the Royal Observatory of Belgium. The LKS – Lomme …


Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou Oct 2015

Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou

Department of Earth, Environment and Sustainability Faculty Publications

In the Asian monsoon region, variations in the stable isotopic composition of speleothems have often been attributed to the "amount effect". However, an increasing number of studies suggest that the "amount effect" in local precipitation is insignificant or even non-existent. To explore this issue further, we examined the variability of daily stable isotopic composition (δ18O) in precipitation from September 2011 to November 2014 in Nanjing, eastern China. We found that intra-seasonal variations of δ18O during summer were not significantly correlated with local rainfall amount but could be linked to changes in the moisture source location and rainout processes in the …


The Science And Practice Of River Restoration, Ellen E. Wohl, Stuart N. Lane, Andrew C. Wilcox Aug 2015

The Science And Practice Of River Restoration, Ellen E. Wohl, Stuart N. Lane, Andrew C. Wilcox

Geosciences Faculty Publications

River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration …


Black Carbon Concentrations In Snow At Tronsen Meadow In Central Washington From 2012 To 2013: Temporal And Spatial Variations And The Role Of Local Forest Fire Activity, Ian Delaney, Susan D. Kaspari, Matthew Jenkins Aug 2015

Black Carbon Concentrations In Snow At Tronsen Meadow In Central Washington From 2012 To 2013: Temporal And Spatial Variations And The Role Of Local Forest Fire Activity, Ian Delaney, Susan D. Kaspari, Matthew Jenkins

Geological Sciences Faculty Scholarship

Characterizing black carbon (BC) concentrations in the seasonal snowpack is of interest because BC deposition on snow can reduce albedo and accelerate melt. In Washington State, USA snowmelt from the seasonal snowpack provides an important source of water resources, but minimal work has been done characterizing BC concentrations in snow in this region. BC concentrations in snow were monitored over two winters (2012 and 2013) at Tronsen Meadow, located near Blewett Pass in the eastern Cascade Mountains in Central Washington, to characterize spatial and temporal variations in BC concentrations, and the processes affecting BC concentrations in the snowpack. BC concentrations …


Factors Affecting Terrigenous Sedimentation In Coastal Bays With Coral Reefs: Implications For Monitoring The Effectiveness Of Watershed Restoration, Whitney Sears Aug 2015

Factors Affecting Terrigenous Sedimentation In Coastal Bays With Coral Reefs: Implications For Monitoring The Effectiveness Of Watershed Restoration, Whitney Sears

Theses

In the Caribbean, sedimentation has been identified as a serious threat to coral reef communities. Although land-based sediment delivery to coastal waters harboring coral reefs occurs under natural conditions, human activities in the watersheds above reefs increases the erosion and delivery of terrigenous sediment to the reefs. Delivery of terrigenous sediment into marine areas below developed watersheds affects sedimentation rates, alters the composition and texture of sediments that are suspended in the water column, and/or sediments that are deposited on the sea floor and on corals.

St. John, U.S. Virgin Islands is an ideal location to study the effects of …


Stable Isotope Analysis Of Bison Latifrons And Paleoecological Inferences, Fabian Ceron Hardy Aug 2015

Stable Isotope Analysis Of Bison Latifrons And Paleoecological Inferences, Fabian Ceron Hardy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bison latifrons was a large Pleistocene herbivore that is traditionally hypothesized to have been adapted to living in forest openings and woodlands. According to this view, the species was primarily a browser of high-growing, woody plants. Very little isotopic work has been conducted on this species, and there have been no prior studies of high altitude localities containing this species. This study aims to address both of these issues.

B. latifrons is known from sites in several states, including California, Idaho, Colorado, Nevada, and Florida, among others. These sites provide diverse examples of this species’ habitat and the opportunity to …


Short-Term Response Of Holcus Lanatus L. (Common Velvetgrass) To Chemical And Manual Control At Yosemite National Park, Usa, Laura J. Jones, Steven M. Ostoja, Matthew L. Brooks, Martin Hutten Jul 2015

Short-Term Response Of Holcus Lanatus L. (Common Velvetgrass) To Chemical And Manual Control At Yosemite National Park, Usa, Laura J. Jones, Steven M. Ostoja, Matthew L. Brooks, Martin Hutten

United States Geological Survey: Staff Publications

One of the highest priority invasive species at both Yosemite and Sequoia and Kings Canyon national parks is Holcus lanatus L. (common velvetgrass), a perennial bunchgrass that invades mid-elevation montane meadows. Despite velvetgrass being a high priority species, there is little information available on control techniques. The goal of this project was to evaluate the short-term response of a single application of common chemical and manual velvetgrass control techniques. The study was conducted at three montane sites in Yosemite National Park. Glyphosate spotspray treatments were applied at 0.5, 1.0, 1.5, and 2.0% concentrations, and compared with hand pulling to evaluate …


Geochemical Analysis Of Surface Materials Surrounding The Bautsch-Gray Mine Superfund Site Near Galena, Illinois, Ryan Plath May 2015

Geochemical Analysis Of Surface Materials Surrounding The Bautsch-Gray Mine Superfund Site Near Galena, Illinois, Ryan Plath

Geology: Student Scholarship & Creative Works

The Bautsch-Gray zinc and lead mine, near Galena, IL, was in operation from the early 1900s until closing in 1975. The mine’s tailings pile has documented elevated lead and zinc concentrations in the surface materials surrounding the site. Numerous floods have caused contaminated sediment to migrate off the mine tailings pile, across Blackjack Road and into an outwash basin, and towards Smallpox Creek. Since this site was designated an EPA priority list Superfund site in 2010, the EPA has conducted numerous remediation efforts. This study attempts to develop a better understanding of the contamination within the soils of the outwash …


Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Land Capability Assessment For Developing Irrigated Agriculture, Henry Smolinski, Shahab Pathan, Paul Galloway, Kus Kuswardiyanto, Justin Laycock May 2015

Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Land Capability Assessment For Developing Irrigated Agriculture, Henry Smolinski, Shahab Pathan, Paul Galloway, Kus Kuswardiyanto, Justin Laycock

Resource management technical reports

This report identifies areas of Cockatoo Sands adjacent to the Ord River Irrigation Area (ORIA), Kununurra, with high potential for developing irrigated agriculture. It builds on a reconnaissance soil survey conducted in 2009 which identified significant areas of sandy and loamy soils in the Kununurra area that could be suitable for agriculture.


Using Kriging, Cokriging, And Gis To Visualize Fe And Mn In Groundwater, Crystal Johnson May 2015

Using Kriging, Cokriging, And Gis To Visualize Fe And Mn In Groundwater, Crystal Johnson

Electronic Theses and Dissertations

For aesthetic, economic, and health-related reasons, allowable concentrations of iron (Fe) and manganese (Mn) found present in drinking water are 0.3 mg/L and 0.05 mg/L, respectively. Water samples taken from private drinking wells in the rural communities within Buncombe County, North Carolina contain amounts of these metals in concentrations higher than the suggested limits. This study focused on bedrock geology, elevation, saprolite thickness, and well depth to determine factors affecting Fe and Mn. Using ArcGIS 10.2, spatial trends in Fe and Mn concentrations ranges were visualized, and estimates of the metal concentrations were interpolated to unmonitored areas. Results from this …


Utilizing Remote Sensing Imagery To Monitor Vegetation Change Within World Heritage Sites, Mimi Eve Hatzis Apr 2015

Utilizing Remote Sensing Imagery To Monitor Vegetation Change Within World Heritage Sites, Mimi Eve Hatzis

Theses and Dissertations

ABSTRACT

World Heritage sites provide a glimpse into the stories and civilizations of the past. There are currently 1007 unique World Heritage properties with 779 being classified as cultural sites, 197 as natural sites, and 31 falling into the categories of both cultural and natural sites (UNESCO & World Heritage Centre, 1992-2015). However, of these 1007 World Heritage sites, at least 46 are categorized as in danger and this number continues to grow. These unique and irreplaceable sites are exceptional because of their universality. Consequently, since World Heritage sites belong to all the people of the world and provide inspiration …


Model Of Residence Time And Analysis Of Nitrogen Removal For Two Constructed Wetlands At The Franklin Demonstration Farm In Lexington, Illinois, Emma Singh Baghel Apr 2015

Model Of Residence Time And Analysis Of Nitrogen Removal For Two Constructed Wetlands At The Franklin Demonstration Farm In Lexington, Illinois, Emma Singh Baghel

Theses and Dissertations

Pollution from nonpoint agricultural runoff has become a major problem facing our streams and rivers today. Not only are fish and aquatic life affected, but so is the quality of our drinking and recreational water resources. Studies have shown that wetlands have proven to be the most cost-effective and low maintenance method of removing nonpoint or diffused contaminate inputs. The biological processes and removal of nutrients in wetlands depend on the total surface area available for microbial activity in the soil and a certain period of water retention time. Since chemical processes take time, the measure of residence time is …


On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan Apr 2015

On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan

Journal of the South Carolina Academy of Science

Models which can estimate environmental transport of radioactive contaminants in natural and engineered systems are required to 1) deploy effective remediation strategies for contaminated sites, 2) design waste repositories for future waste streams, and 3) ensure protection of human and environmental health in all cases. These models require accurate transport parameters in order to correctly predict how these contaminants will move in the subsurface. This work aimed to determine more accurately the distribution coefficients for radium and strontium sorption to Savannah River Site (SRS) soils. Radium and strontium sorption to the soils was found to be highly dependent upon ionic …


Habitat Fragmenta-On In The Sebago Lake Watershed, Jared Lank Apr 2015

Habitat Fragmenta-On In The Sebago Lake Watershed, Jared Lank

Thinking Matters Symposium Archive

The goal of this research was to evaluate the extent of land use change occurring in the Sebago lake watershed of southern Maine. The primary data set used was Landsat 7 Near Infrared satellite imagery of the region which was analyzed with ESRI’s ArcGIS soQware. Data was clipped to the Portland Water District’s sub watershed shape file and analyzed with the soQware’s image analysis ‘difference’ tool which calculates the differences in pixel values between to raster datasets. The 2013 Landsat reclassifica-on was compared to 1987, 1995 and 2009 reclassifica-ons. NOAA’s Habitat Priority Planner plugin tool was also u-lized in order …


Karst Porosity Estimations From Archive Cave Surveys - Studies In The Buda Thermal Karst System (Hungary), Gáspár Albert, Magdolna Virág, Anita Erőss Feb 2015

Karst Porosity Estimations From Archive Cave Surveys - Studies In The Buda Thermal Karst System (Hungary), Gáspár Albert, Magdolna Virág, Anita Erőss

International Journal of Speleology

The Buda Thermal Karst System is located under the densely populated hills of Budapest. One of its caves (Pál-völgy Cave System) is the longest cave of Hungary with 30.1 km. The research was done in this area as a methodological study to estimate karst porosity parameters of aquifers or hydrocarbon reservoirs. In this study two modeling methods are demonstrated. The volumetric modeling method was primarily aimed to determine the macro-scale (>0.5 m) conduit porosity (referred as macroporosity) of the study area as percentage of the incorporating limestone and marl. This method is based on archive survey data (maps and …


Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Michael Marasa Jan 2015

Cars And Karst: Investigating The National Corvette Museum Sinkhole, Jason S. Polk, Leslie North, Ric Federico, Brian Ham, Dan Nedvidek, Kegan Mcclanahan, Pat Kambesis, Michael Marasa

Earth, Environmental, and Atmospheric Sciences Faculty Publications

On February 12th, 2014, a sinkhole occurred at the National Corvette Museum in Bowling Green, Kentucky. The collapse happened inside part of the building known as the Skydome and eight Corvettes on display were lost into the void that opened in the concrete floor. In this region of Kentucky, known as the Pennyroyal sinkhole plain, subsidence and cover collapse sinkholes are commonly found throughout the landscape. This iconic karst region in the United States is also home to Mammoth Cave, the longest cave in the world, and thousands of other caves and karst features. Investigation of the sinkhole collapse began …


Training Conservation Practitioners To Be Better Decision Makers, Fred Johnson, Mitchell J. Eaton, James H. Williams, Gitte H. Jensen, Jesper Madsen Jan 2015

Training Conservation Practitioners To Be Better Decision Makers, Fred Johnson, Mitchell J. Eaton, James H. Williams, Gitte H. Jensen, Jesper Madsen

United States Geological Survey: Staff Publications

Traditional conservation curricula and training typically emphasizes only one part of systematic decision making (i.e., the science), at the expense of preparing conservation practitioners with critical skills in values-setting, working with decision makers and stakeholders, and effective problem framing. In this article we describe how the application of decision science is relevant to conservation problems and suggest how current and future conservation practitioners can be trained to be better decision makers. Though decision-analytic approaches vary considerably, they all involve: (1) properly formulating the decision problem; (2) specifying feasible alternative actions; and (3) selecting criteria for evaluating potential outcomes. Two approaches …


Phosphorus Retention In A Lowland Neotropical Stream Following An Eight-Year Enrichment Experiment, Gaston E. Small, Marcelo Ardón, John H. Duff, Alan P. Jackman, Alonso Ramírez, Frank J. Triska, Catherine M. Pringle Jan 2015

Phosphorus Retention In A Lowland Neotropical Stream Following An Eight-Year Enrichment Experiment, Gaston E. Small, Marcelo Ardón, John H. Duff, Alan P. Jackman, Alonso Ramírez, Frank J. Triska, Catherine M. Pringle

United States Geological Survey: Staff Publications

Human alteration of the global P cycle has led to widespread P loading in freshwater ecosystems. Much research has been devoted to the capacity of wetlands and lakes to serve as long-term sinks for P inputs from the watershed, but we know much less about the potential of headwater streams to serve in this role. We assessed storage and retention of P in biotic and abiotic compartments after an 8-y experimental P addition to a 1st-order stream in a Neotropical wet forest. Sediment P extractions indicated that nearly all P storage was in the form of Fe- and Al-bound P …


Aquatic Pollution Increases Use Of Terrestrial Prey Subsidies By Stream Fish, Johanna M. Kraus, Justin F. Pomeranz, Andrew S. Todd, David M. Walters, Travis S. Schmidt, Richard B. Wanty Jan 2015

Aquatic Pollution Increases Use Of Terrestrial Prey Subsidies By Stream Fish, Johanna M. Kraus, Justin F. Pomeranz, Andrew S. Todd, David M. Walters, Travis S. Schmidt, Richard B. Wanty

United States Geological Survey: Staff Publications

1. Stream food webs are connected with their riparian zones through cross-ecosystem movements of energy and nutrients. The use and impact of terrestrial subsidies on aquatic consumers is often determined by in situ biomass of aquatic prey. Thus, stressors such as aquatic pollutants that greatly reduce aquatic secondary production could increase the need for and reliance of stream consumers on terrestrial resource subsidies.

2. To test this hypothesis, we surveyed stream fish, their diets, and resource availability in 16 subalpine streams over a regional gradient of trace metals known to strongly impact aquatic insect communities (i.e. fish prey) in …


Uranium-Series Ages Of Fossil Corals From Mallorca, Spain: The “Neotyrrhenian” High Stand Of The Mediterranean Sea Revisited, Daniel R. Muhs, Kathleen R. Simmons, Joaquín Meco, Naomi Porat Jan 2015

Uranium-Series Ages Of Fossil Corals From Mallorca, Spain: The “Neotyrrhenian” High Stand Of The Mediterranean Sea Revisited, Daniel R. Muhs, Kathleen R. Simmons, Joaquín Meco, Naomi Porat

United States Geological Survey: Staff Publications

The emergent marine deposits of the Mediterranean basin have been recognized as an important record of Quaternary sea level history for more than a century. Previous workers identified what have been interpreted to be two separate high stands of sea in the late Quaternary, namely the “Eutyrrhenian” (thought to be ~120 ka) and the “Neotyrrhenian” (thought to be either ~100 ka or ~80 ka). On Mallorca, Spain, both of these named deposits lie close to present sea level, implying paleo-sea levels slightly above present during both marine isotope stages (MIS) 5.5/5e and either 5.3/5c or 5.1/5a. If these interpretations are …