John Karl Bohlke, PhD
Dr. John Karl Bohlke is a Scientist Emeritus affiliated with the Earth Systems Processes Division and the Reston Stable Isotope Laboratory of the USGS Water Resources Mission Area.
Dr. John Karl (JK) Bohlke retired as a Senior Research Scientist and currently serves as a Scientist Emeritus affiliated with the Earth System Processes Division and the Reston Stable Isotope Laboratory of the Water Mission Area. During his career with USGS, he has studied processes related to both mineral resources and water resources. His published work includes field and laboratory-based studies of water-rock interactions, geochronology, and chemical transport in diverse hydrogeologic settings. Recent activities include development of stable isotopic methods and applications in hydrology and biogeochemistry, use of isotopes and environmental tracers to determine transport and reaction rates in groundwater and surface water, and multidisciplinary investigations of contaminant origin and migration. Selected priority topics related to water quality include excess nutrients and inorganic contaminants, effects of agriculture and wastewater disposal practices, watershed responses to land use change, groundwater/surface water interactions, and environmental forensics.
Professional Experience
Hydrologist, National Research Program and Earth System Processes Division, Water Mission Area, US Geological Survey, Reston, Virginia (since 1991)
Geologist, Eastern Mineral Resources, US Geological Survey, Reston, Virginia
Postdoc (Geoscience), Argonne National Laboratory, Chicago, Illinois
Geologist, Western Mineral Resources, US Geological Survey, Menlo Park, California
Cartographer, US Soil Conservation Service, Hyattsville, Maryland
Education and Certifications
PhD (Geology and Geophysics), University of California, Berkeley, California
MS (Marine Geology), Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Florida
BS (Geology), University of Michigan, Ann Arbor, Michigan
Science and Products
Filter Total Items: 201
Four-dimensional isotopic approach to identify perchlorate sources in groundwater: Application to the Rialto-Colton and Chino subbasins, southern California (USA) Four-dimensional isotopic approach to identify perchlorate sources in groundwater: Application to the Rialto-Colton and Chino subbasins, southern California (USA)
Perchlorate (ClO4−) in groundwater can be from synthetic or natural sources. Natural sources include ClO4− associated with historical application of imported natural nitrate fertilizer from the Atacama Desert of Chile, and indigenous ClO4− that accumulates locally in arid regions from atmospheric deposition. The Rialto-Colton groundwater subbasin, 80 km east of Los Angeles, California...
Authors
Paul Hatzinger, J.K. Bohlke, Neil Sturchio, John Izbicki, Nicholas Teague
Geochemical conditions and nitrogen transport in nearshore groundwater and the subterranean estuary at a Cape Cod embayment, East Falmouth, Massachusetts, 2013–14 Geochemical conditions and nitrogen transport in nearshore groundwater and the subterranean estuary at a Cape Cod embayment, East Falmouth, Massachusetts, 2013–14
Nitrogen transport and transformation were studied during 2013 to 2014 by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, in a subterranean estuary beneath onshore locations on the Seacoast Shores peninsula, a residential area in Falmouth, Massachusetts, served by septic systems and cesspools, and adjacent offshore locations in the Eel River, a...
Authors
John Colman, Denis LeBlanc, J.K. Bohlke, Timothy D. McCobb, Kevin Kroeger, Marcel Belaval, Thomas Cambareri, Gillian Pirolli, T. Brooks, Mary Garren, Tobias Stover, Ann Keeley
Tracing the cycling and fate of the munition, Hexahydro-1,3,5-trinitro-1,3,5-triazine in a simulated sandy coastal marine habitat with a stable isotopic tracer, 15N-[RDX] Tracing the cycling and fate of the munition, Hexahydro-1,3,5-trinitro-1,3,5-triazine in a simulated sandy coastal marine habitat with a stable isotopic tracer, 15N-[RDX]
Coastal marine habitats become contaminated with the munitions constituent, Hexahydro-1,3,5-trinitro-1,3,5-trazine (RDX), via military training, weapon testing and leakage of unexploded ordnance. This study used 15N labeled RDX in simulated aquarium-scale coastal marine habitat containing seawater, sediment, and biota to track removal pathways from surface water including sorption onto
Authors
Thivanka Ariyarathna, Mark Ballentine, Penny Vlahos, Richard Smith, Christopher Cooper, J.K. Bohlke, Stephen Fallis, Thomas Groshens, Craig Tobias
Minimum energy requirements for desalination of brackish groundwater in the United States with comparison to international datasets Minimum energy requirements for desalination of brackish groundwater in the United States with comparison to international datasets
This paper uses chemical and physical data from a large 2017 U.S. Geological Surveygroundwater dataset with wells in the U.S. and three smaller international groundwater datasets with wells primarily in Australia and Spain to carry out a comprehensive investigation of brackish groundwater composition in relation to minimum desalinationenergy costs. First, we compute the site-specific...
Authors
Yvana Ahdab, Gregory Thiel, J.K. Bohlke, Jennifer Stanton, John Lienhard
Validation of stable isotope ratio analysis to document the biodegradation and natural attenuation of RDX, ESTCP Project ER-201208 Validation of stable isotope ratio analysis to document the biodegradation and natural attenuation of RDX, ESTCP Project ER-201208
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a common soil contaminant at current and former military facilities, including many training and testing ranges. Because RDX is readily transported through soils to the subsurface, this nitramine explosive now also impacts groundwater and drinking water at numerous locations across the country. A significant issue with RDX contamination on...
Authors
Paul Hatzinger, Mark Fuller, Neil Sturchio, J.K. Bohlke
Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report) Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report)
The standard atomic weights of the elements apply to normal materials. Since 1984, the Commission on Isotopic Abundances and Atomic Weights (Commission) has defined a normal material as: “The material is a reasonably possible source for this element or its compounds in commerce, for industry or science; the material is not itself studied for some extraordinary anomaly and its isotopic...
Authors
Tyler Coplen, Norman Holden, Michael Wieser, J.K. Bohlke
Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needs Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needs
Rationale Despite a long history and growing interest in isotopic analyses of N2O, there is a lack of isotopically characterized N2O isotopic reference materials (standards) to enable normalization and reporting of isotope‐delta values. Here we report the isotopic characterization of two pure N2O gas reference materials, USGS51 and USGS52, which are now available for laboratory...
Authors
Nathaniel Ostrom, Hasand Gandhi, Tyler Coplen, Sakae Toyoda, J.K. Bohlke, Willi Brand, Karen Casciotti, Jens Dyckmans, Anette Giesemann, Joachim Mohn, Reinhard Well, Longfei Yu, Naohiro Yoshida
Response of deep groundwater to land use change in desert basins of the Trans-Pecos region, Texas, USA: Effects on infiltration, recharge, and nitrogen fluxes Response of deep groundwater to land use change in desert basins of the Trans-Pecos region, Texas, USA: Effects on infiltration, recharge, and nitrogen fluxes
Quantifying the effects of anthropogenic processes on groundwater in arid regions can be complicated by thick unsaturated zones with long transit times. Human activities can alter water and nutrient fluxes, but their impact on groundwater is not always clear. This study of basins in the Trans-Pecos region of Texas links anthropogenic land use and vegetation change with alterations to...
Authors
Wendy Robertson, J.K. Bohlke, John Sharp
Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study
Quantitative information about the fate of applied nitrate (NO3-N) in pulse-flow constructed wetlands is essential for designing wetland treatment systems and assessing their nitrogen removal services for agricultural and stormwater applications. Although many studies have documented NO3-N losses in wetlands, controlled experiments indicating the relative importance of different...
Authors
Tiffany Messer, Michael Burchell, J.K. Bohlke, Craig Tobias
Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences
Rationale Perchlorate (ClO4−) is a common trace constituent of water, soils, and plants; it has both natural and synthetic sources and is subject to biodegradation. The stable isotope ratios of Cl and O provide three independent quantities for ClO4− source attribution and natural attenuation studies: δ37Cl, δ18O, and δ17O (or Δ17O or 17Δ) values. Documented reference materials...
Authors
J.K. Bohlke, Stanley Mroczkowski, Neil Sturchio, Linnea Heraty, Kent Richman, Donald Sullivan, Kris Griffith, Baohua Gu, Paul B. Hatzinger
Density-driven free-convection model for isotopically fractionated geogenic nitrate in sabkha brine Density-driven free-convection model for isotopically fractionated geogenic nitrate in sabkha brine
Subsurface brines with high nitrate (NO3−) concentration are common in desert environments as atmospheric nitrogen is concentrated by the evaporation of precipitation and little nitrogen uptake. However, in addition to having an elevated mean concentration of ∼525 mg/L (as N), NO3− in the coastal sabkhas of Abu Dhabi is enriched in 15N (mean δ15N ∼17‰), which is an enigma. A NO3− solute...
Authors
Warren W. Wood, J.K. Bohlke
Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data
Natural perchlorate (ClO4−) in soil and groundwater exhibits a wide range in stable isotopic compositions (δ37Cl, δ18O, and Δ17O), indicating that ClO4− may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO4−, but little is known about their ability to alter its isotopic composition. We examined the...
Authors
Nubia Estrada, J.K. Bohlke, Neil Sturchio, Baohua Gu, Greg Harvey, Kent Burkey, David Grantz, Margaret McGrath, Todd Anderson, Balaji Rao, Ritesh Sevanthi, Paul Hatzinger, W. Jackson
Non-USGS Publications**
Sturchio, N.C., Böhlke, J.K., and Binz, C.M., 1989, Radium-thorium disequilibrium and zeolite-water ion exchange in a Yellowstone hydrothermal environment. Geochimica et Cosmochimica Acta, v. 53, p. 1025-1034, https://doi.org/10.1016/0016-7037(89)90207-X.
Abrajano, T.A., Bates, J.K., and Böhlke, J.K., 1988, Linear free energy relationships in glass corrosion. Materials Issues in Art and Archeaology, Materials Research Society Proceedings, v. 125, p. 383-392, https://www.osti.gov/biblio/7179346/.
Abrajano, T.A., Sturchio, N.C., Böhlke, J.K., Poreda, R.J., Lyon, G.L., and Stevens, C.M., 1988, Methane-hydrogen gas seeps, Zambales, Philippines: Deep or shallow origin. Chemical Geology, v. 71, p. 211-222, https://doi.org/10.1016/0009-2541(88)90116-7.
Böhlke, 1988, Carbonate-sulfide equilibria and "stratabound" disseminated epigenetic gold mineralization: A proposal based on examples from Alleghany, California. Applied Geochemistry, v. 3, p. 499-516, https://doi.org/10.1016/0883-2927(88)90022-4.
Böhlke, J.K., Alt, J.C., and Muehlenbachs, K., 1984, Oxygen isotope-water relations in altered deep-sea basalts: Low temperature mineralogic controls. Canadian Journal of Earth Sciences, v. 21, p. 67-77, https://doi.org/10.1139/e84-008.
Böhlke, J.K., Honnorez, J., Honnorez-Guerstein, B.M., Muehlenbachs, K., and Petersen, N., 1981, Heterogeneous alteration of the upper oceanic crust: Correlation of rock chemistry, magnetic properties, and O-isotope ratios with alteration patterns in basalts from Site 396B, DSDP. Journal of Geophysical Research, Solid Earth, v. 86, p. 7935-7950, https://doi.org/10.1029/JB086iB09p07935.
Böhlke, J.K., Honnorez, J., and Honnorez-Guerstein, B.-M., 1980, Alteration of basalts from Site 396B, Deep Sea Drilling Project, petrographic and mineralogic studies. Contributions to Mineralogy and Petrology, v. 73, p. 341-364, https://doi.org/10.1007/BF00376628.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 201
Four-dimensional isotopic approach to identify perchlorate sources in groundwater: Application to the Rialto-Colton and Chino subbasins, southern California (USA) Four-dimensional isotopic approach to identify perchlorate sources in groundwater: Application to the Rialto-Colton and Chino subbasins, southern California (USA)
Perchlorate (ClO4−) in groundwater can be from synthetic or natural sources. Natural sources include ClO4− associated with historical application of imported natural nitrate fertilizer from the Atacama Desert of Chile, and indigenous ClO4− that accumulates locally in arid regions from atmospheric deposition. The Rialto-Colton groundwater subbasin, 80 km east of Los Angeles, California...
Authors
Paul Hatzinger, J.K. Bohlke, Neil Sturchio, John Izbicki, Nicholas Teague
Geochemical conditions and nitrogen transport in nearshore groundwater and the subterranean estuary at a Cape Cod embayment, East Falmouth, Massachusetts, 2013–14 Geochemical conditions and nitrogen transport in nearshore groundwater and the subterranean estuary at a Cape Cod embayment, East Falmouth, Massachusetts, 2013–14
Nitrogen transport and transformation were studied during 2013 to 2014 by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, in a subterranean estuary beneath onshore locations on the Seacoast Shores peninsula, a residential area in Falmouth, Massachusetts, served by septic systems and cesspools, and adjacent offshore locations in the Eel River, a...
Authors
John Colman, Denis LeBlanc, J.K. Bohlke, Timothy D. McCobb, Kevin Kroeger, Marcel Belaval, Thomas Cambareri, Gillian Pirolli, T. Brooks, Mary Garren, Tobias Stover, Ann Keeley
Tracing the cycling and fate of the munition, Hexahydro-1,3,5-trinitro-1,3,5-triazine in a simulated sandy coastal marine habitat with a stable isotopic tracer, 15N-[RDX] Tracing the cycling and fate of the munition, Hexahydro-1,3,5-trinitro-1,3,5-triazine in a simulated sandy coastal marine habitat with a stable isotopic tracer, 15N-[RDX]
Coastal marine habitats become contaminated with the munitions constituent, Hexahydro-1,3,5-trinitro-1,3,5-trazine (RDX), via military training, weapon testing and leakage of unexploded ordnance. This study used 15N labeled RDX in simulated aquarium-scale coastal marine habitat containing seawater, sediment, and biota to track removal pathways from surface water including sorption onto
Authors
Thivanka Ariyarathna, Mark Ballentine, Penny Vlahos, Richard Smith, Christopher Cooper, J.K. Bohlke, Stephen Fallis, Thomas Groshens, Craig Tobias
Minimum energy requirements for desalination of brackish groundwater in the United States with comparison to international datasets Minimum energy requirements for desalination of brackish groundwater in the United States with comparison to international datasets
This paper uses chemical and physical data from a large 2017 U.S. Geological Surveygroundwater dataset with wells in the U.S. and three smaller international groundwater datasets with wells primarily in Australia and Spain to carry out a comprehensive investigation of brackish groundwater composition in relation to minimum desalinationenergy costs. First, we compute the site-specific...
Authors
Yvana Ahdab, Gregory Thiel, J.K. Bohlke, Jennifer Stanton, John Lienhard
Validation of stable isotope ratio analysis to document the biodegradation and natural attenuation of RDX, ESTCP Project ER-201208 Validation of stable isotope ratio analysis to document the biodegradation and natural attenuation of RDX, ESTCP Project ER-201208
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a common soil contaminant at current and former military facilities, including many training and testing ranges. Because RDX is readily transported through soils to the subsurface, this nitramine explosive now also impacts groundwater and drinking water at numerous locations across the country. A significant issue with RDX contamination on...
Authors
Paul Hatzinger, Mark Fuller, Neil Sturchio, J.K. Bohlke
Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report) Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report)
The standard atomic weights of the elements apply to normal materials. Since 1984, the Commission on Isotopic Abundances and Atomic Weights (Commission) has defined a normal material as: “The material is a reasonably possible source for this element or its compounds in commerce, for industry or science; the material is not itself studied for some extraordinary anomaly and its isotopic...
Authors
Tyler Coplen, Norman Holden, Michael Wieser, J.K. Bohlke
Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needs Preliminary assessment of stable nitrogen and oxygen isotopic composition of USGS51 and USGS52 nitrous oxide reference gases and perspectives on calibration needs
Rationale Despite a long history and growing interest in isotopic analyses of N2O, there is a lack of isotopically characterized N2O isotopic reference materials (standards) to enable normalization and reporting of isotope‐delta values. Here we report the isotopic characterization of two pure N2O gas reference materials, USGS51 and USGS52, which are now available for laboratory...
Authors
Nathaniel Ostrom, Hasand Gandhi, Tyler Coplen, Sakae Toyoda, J.K. Bohlke, Willi Brand, Karen Casciotti, Jens Dyckmans, Anette Giesemann, Joachim Mohn, Reinhard Well, Longfei Yu, Naohiro Yoshida
Response of deep groundwater to land use change in desert basins of the Trans-Pecos region, Texas, USA: Effects on infiltration, recharge, and nitrogen fluxes Response of deep groundwater to land use change in desert basins of the Trans-Pecos region, Texas, USA: Effects on infiltration, recharge, and nitrogen fluxes
Quantifying the effects of anthropogenic processes on groundwater in arid regions can be complicated by thick unsaturated zones with long transit times. Human activities can alter water and nutrient fluxes, but their impact on groundwater is not always clear. This study of basins in the Trans-Pecos region of Texas links anthropogenic land use and vegetation change with alterations to...
Authors
Wendy Robertson, J.K. Bohlke, John Sharp
Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study
Quantitative information about the fate of applied nitrate (NO3-N) in pulse-flow constructed wetlands is essential for designing wetland treatment systems and assessing their nitrogen removal services for agricultural and stormwater applications. Although many studies have documented NO3-N losses in wetlands, controlled experiments indicating the relative importance of different...
Authors
Tiffany Messer, Michael Burchell, J.K. Bohlke, Craig Tobias
Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences
Rationale Perchlorate (ClO4−) is a common trace constituent of water, soils, and plants; it has both natural and synthetic sources and is subject to biodegradation. The stable isotope ratios of Cl and O provide three independent quantities for ClO4− source attribution and natural attenuation studies: δ37Cl, δ18O, and δ17O (or Δ17O or 17Δ) values. Documented reference materials...
Authors
J.K. Bohlke, Stanley Mroczkowski, Neil Sturchio, Linnea Heraty, Kent Richman, Donald Sullivan, Kris Griffith, Baohua Gu, Paul B. Hatzinger
Density-driven free-convection model for isotopically fractionated geogenic nitrate in sabkha brine Density-driven free-convection model for isotopically fractionated geogenic nitrate in sabkha brine
Subsurface brines with high nitrate (NO3−) concentration are common in desert environments as atmospheric nitrogen is concentrated by the evaporation of precipitation and little nitrogen uptake. However, in addition to having an elevated mean concentration of ∼525 mg/L (as N), NO3− in the coastal sabkhas of Abu Dhabi is enriched in 15N (mean δ15N ∼17‰), which is an enigma. A NO3− solute...
Authors
Warren W. Wood, J.K. Bohlke
Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data
Natural perchlorate (ClO4−) in soil and groundwater exhibits a wide range in stable isotopic compositions (δ37Cl, δ18O, and Δ17O), indicating that ClO4− may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO4−, but little is known about their ability to alter its isotopic composition. We examined the...
Authors
Nubia Estrada, J.K. Bohlke, Neil Sturchio, Baohua Gu, Greg Harvey, Kent Burkey, David Grantz, Margaret McGrath, Todd Anderson, Balaji Rao, Ritesh Sevanthi, Paul Hatzinger, W. Jackson
Non-USGS Publications**
Sturchio, N.C., Böhlke, J.K., and Binz, C.M., 1989, Radium-thorium disequilibrium and zeolite-water ion exchange in a Yellowstone hydrothermal environment. Geochimica et Cosmochimica Acta, v. 53, p. 1025-1034, https://doi.org/10.1016/0016-7037(89)90207-X.
Abrajano, T.A., Bates, J.K., and Böhlke, J.K., 1988, Linear free energy relationships in glass corrosion. Materials Issues in Art and Archeaology, Materials Research Society Proceedings, v. 125, p. 383-392, https://www.osti.gov/biblio/7179346/.
Abrajano, T.A., Sturchio, N.C., Böhlke, J.K., Poreda, R.J., Lyon, G.L., and Stevens, C.M., 1988, Methane-hydrogen gas seeps, Zambales, Philippines: Deep or shallow origin. Chemical Geology, v. 71, p. 211-222, https://doi.org/10.1016/0009-2541(88)90116-7.
Böhlke, 1988, Carbonate-sulfide equilibria and "stratabound" disseminated epigenetic gold mineralization: A proposal based on examples from Alleghany, California. Applied Geochemistry, v. 3, p. 499-516, https://doi.org/10.1016/0883-2927(88)90022-4.
Böhlke, J.K., Alt, J.C., and Muehlenbachs, K., 1984, Oxygen isotope-water relations in altered deep-sea basalts: Low temperature mineralogic controls. Canadian Journal of Earth Sciences, v. 21, p. 67-77, https://doi.org/10.1139/e84-008.
Böhlke, J.K., Honnorez, J., Honnorez-Guerstein, B.M., Muehlenbachs, K., and Petersen, N., 1981, Heterogeneous alteration of the upper oceanic crust: Correlation of rock chemistry, magnetic properties, and O-isotope ratios with alteration patterns in basalts from Site 396B, DSDP. Journal of Geophysical Research, Solid Earth, v. 86, p. 7935-7950, https://doi.org/10.1029/JB086iB09p07935.
Böhlke, J.K., Honnorez, J., and Honnorez-Guerstein, B.-M., 1980, Alteration of basalts from Site 396B, Deep Sea Drilling Project, petrographic and mineralogic studies. Contributions to Mineralogy and Petrology, v. 73, p. 341-364, https://doi.org/10.1007/BF00376628.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.