The Philip M. Smith Graduate Research Grant for Cave and Karst Research
 
2017 Grants
 
Samantha Feist ($2,000)
M.S. Candidate
School of Geography and Earth Science
McMaster University

Understanding sediment pathways in Hidden River Cave, Kentucky

Abstract - Examining sediment transport in cave systems is difficult due to the complex nature of karst systems, and it is not as well understood as surficial systems. Cave sedimentology studies explore sediment transport and deposition within cave systems. The objectives of this study are to better understand sediment transport in karst cave systems by examining the sedimentological record in Hidden River Cave in Horse Cave, Kentucky. Hidden River Cave is an active cave system recovering from contamination, providing a unique opportunity in the sediment record to understand past sedimentation in the system. Additionally, current research has uncovered microplastics, “plastic particles less than 5mm in diameter”1 in surficial sediment samples from Hidden River Cave. Further exploring the extent of microplastic contamination combined with exploring the sediment record in the cave will allow for better understanding of sediment transport in Kentucky cave systems and others in similar karst landscapes.

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Robert J. Scharping ($3,000)
Ph.D. Student
Department of Cell Biology, Microbiology, and Molecular Biology
University of South Florida

Impacts of groundwater extraction on a karst aquifer ecosystem and the use of ecological surrogacy for the management of underwater caves

Abstract- Karst springs in Florida support important surface ecosystems and provide valuable services to humans. Spring water is sourced from underlying aquifers, which support their own taxonomically rich microbial communities. Microbial communities are particularly sensitive to environmental disturbance and may therefore be useful indicators of aquifer ecosystem condition. One type of disturbance occurring naturally in karst aquifers is spring flow reversal, which brings surface water directly into dissolution conduits. This natural phenomenon has yet to be recorded as a result of human activity, but it may be happening at Sulphur Springs, Tampa, FL, due to groundwater extraction and drawdown of the local water table. We will deploy acoustic Doppler velocimeters and water quality multiprobes in the Sulphur Springs karst conduit to characterize the hydrological and physical profiles of this site. We will also analyze water nutrient profiles spectrophotometrically and characterize the groundwater biological community through molecular methods. We will simultaneously study the same ecological parameters at a pristine site, Crab Creek Spring, as a reference. Resource managers of the City of Tampa will work with us to experimentally manipulate the activity of municipal pumps at Sulphur Springs, which will alter the flow within the conduit and potentially induce spring reversals. This research will identify if spring reversals at Sulphur Springs are caused by groundwater extraction, and what impacts hydrological condition has on aquifer ecology. We will also identify the ecological factors that should be managed for the conservation of karst spring ecosystems in Florida and around the world.

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Natasha Sekhon ($2,000)
Ph.D. Student
Department of Geological Sciences
University of Texas at Austin

Validating near-entrance cave deposits as a high-resolution sub-annual paleotemperature proxy in New Mexico

Abstract - The geochemistry of speleothems (cave deposits) are used to reconstruct past terrestrial climate (i.e., rainfall amount, moisture source, vegetation) on annual (high-resolution) or centennial (low-resolution) time-scales, have been commonly studied from deep parts of caves. Recent studies of speleothems from the traditionally overlooked near-entrance cave zones (Webster et al., 2007) and shallow caves (Flohr et al., 2017) have displayed the potential to study climate variability on a seasonal timescale from these locations. Speleothem scientists have long avoided the near-entrance cave zones and shallow caves because of concerns regarding evaporation, kinetic isotope effects and biological activity. A recent cave monitoring and speleothem calcite study (Feng et al., 2014) from a small, well-ventilated, near-entrance cave zone (Westcave) in central Texas shows temperature of surface air as the primary control of calcite growth on a seasonal time scale. I propose to couple modern cave monitoring, stable isotope (δ18O) and trace element (Mg/Ca and Sr/Ca) analysis in a shallow cave to test the potential of recording seasonality of temperature in speleothems. The focus of the study is a shallow cave from New Mexico in the southwestern United States similar to the Westcave setting of being well ventilated with near-atmospheric CO2 concentrations and temperatures. The added motivation to study southwestern United States is that it is a moisture limited and drought-prone region, which is poorly studied for severity of pre-instrumental droughts. The results from the study will have implications for reconstructing high-resolution terrestrial paleoclimate records to study seasonality in temperature in drought-prone regions using speleothems.

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Hali Steinmann ($1,600)
M.S. Student
Department of Geography and Geology
Western Kentucky University

A geomorphic approach to understanding karstification in the late‐Mississippian Pennington Formation, Savage Gulf State Natural Area, Tennessee

Abstract - Karst processes drive landscape evolution on the Cumberland Plateau, a physiographic province spanning from northern Alabama and Georgia through Tennessee into southeastern Kentucky. Situated near the crown of the plateau’s stratigraphic sequence is the Pennington Formation, a heterogeneous geologic unit that contains intermittent soluble rock layers such as limestone and dolostone, along with varying amounts of shale, siltstone, and sandstone. This research will take a geomorphological approach with the goal of understanding solutional processes and structural and lithologic controls on drainage in the Pennington Formation in Tennessee’s Savage Gulf State Natural Area. The research questions are: 1) what are the major controls on speleogenesis in the Pennington Formation?, 2) how might the presence of soluble rocks in this unit influence the overall karstification and denudation of the Cumberland Plateau?, and 3) How can morphometric indices be applied to cave survey data in order to distinguish between cave types and interpret the effects of speleogenetic processes? The proposed research will consist of geologic mapping and a karst feature inventory of the Pennington Formation, a detailed survey of Pennington caves, fluorescent dye tracer tests and chemical analysis of the hydrologic system, morphometric analysis of cave survey data, and spatial analysis using a GIS. Karstification of the Pennington Formation has implications not only for geomorphology, but also for local ecology and biodiversity, water quality, and land management.

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Barbara E. Wortham ($2,400)
Ph.D. Candidate
Department of Earth and Environmental Sciences
University of California, Davis

Reconstructing paleo-linkages between central California’s hydroclimate and global climate change

Abstract - Prolonged drought over several years severely impacted California’s water resources, indicating the need for a better understanding of how global climate can affect California’s precipitation patterns. I propose to monitor the evolution of surface precipitation geochemistry in response to cave-related processes by measuring environmental surface conditions above and within two Sierran foothill caves. The monitoring project will allow for a greater understanding of how individual storms and seasons impact the isotopic and physical parameters of the cave system and will lead to a framework to be used in interpreting speleothem based paleoclimate proxies. Cave monitoring is intrinsically linked to the longer research goal, which is to develop and investigate the feasibility of using speleothem fluid inclusion stable isotope and noble gas compositions to assess quantitative changes in California temperature and precipitation. Results from this work will include seasonal variability in the stable isotopes in precipitation and drip water in these locations, how individual storms impact those values, how sensitive noble gas concentrations in dripwater are to changes in cave air temperature, and how in cave systematics relate to precipitated calcite. The proposed project is of great societal significance as it will lead to a better understanding of California hydroclimate and the link to global climate change.

Page last updated or validated on January 26, 2019