Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

PDF

Dartmouth College

Humans

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Noble Gases Identify The Mechanisms Of Fugitive Gas Contamination In Drinking-Water Wells Overlying The Marcellus And Barnett Shales, Thomas H. Darrah, Avner Vengosh, Robert B. Jackson, Nathaniel R. R. Warner, Robert J. Poreda Sep 2014

Noble Gases Identify The Mechanisms Of Fugitive Gas Contamination In Drinking-Water Wells Overlying The Marcellus And Barnett Shales, Thomas H. Darrah, Avner Vengosh, Robert B. Jackson, Nathaniel R. R. Warner, Robert J. Poreda

Dartmouth Scholarship

Horizontal drilling and hydraulic fracturing have enhanced energy production but raised concerns about drinking-water contamination and other environmental impacts. Identifying the sources and mechanisms of contamination can help improve the environmental and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells overlying the Marcellus and Barnett Shales, respectively, examining hydrocarbon abundance and isotopic compositions (e.g., C2H6/CH4, δ13C-CH4) and providing, to our knowledge, the first comprehensive analyses of noble gases and their isotopes (e.g., 4He, 20Ne, 36Ar) in groundwater near shale-gas wells. We addressed two questions. (i) Are elevated levels of hydrocarbon gases in …


Relationship Between Altitude And Lithium In Groundwater In The United States Of America: Results Of A 1992–2003 Study, Rebekah S. Huber, Namkug Kim, Carl E. Renshaw, Perry F. Renshaw, Douglas Kondo Jan 2014

Relationship Between Altitude And Lithium In Groundwater In The United States Of America: Results Of A 1992–2003 Study, Rebekah S. Huber, Namkug Kim, Carl E. Renshaw, Perry F. Renshaw, Douglas Kondo

Dartmouth Scholarship

Therapeutic dosages of lithium are known to reduce suicide rates, which has led to investigations of confounding environmental risk factors for suicide such as lithium in groundwater. It has been speculated that this might play a role in the potential relationship between suicide and altitude. A recent study in Austria involving geospatial analysis of lithium in groundwater and suicide found lower levels of lithium at higher altitudes. Since there is no reason to suspect this correlation is universal given variation in geology, the current study set out to investigate the relationship between altitude and lithium in groundwater in the United …


Benthic And Pelagic Pathways Of Methylmercury Bioaccumulation In Estuarine Food Webs Of The Northeast United States, Celia Y. Chen, Mark E. Borsuk, Deenie M. Bugge, Terill Hollweg Jan 2014

Benthic And Pelagic Pathways Of Methylmercury Bioaccumulation In Estuarine Food Webs Of The Northeast United States, Celia Y. Chen, Mark E. Borsuk, Deenie M. Bugge, Terill Hollweg

Dartmouth Scholarship

Methylmercury (MeHg) is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine). MeHg concentrations …