Blaine McCleskey is a Research Chemist for the USGS Water Resources Mission Area.
Blaine McCleskey started his career with the U.S. Geological Survey in 1997 as a chemist in the National Research Program. In 2010, he obtained a Ph.D. from the University of Colorado where he developed a method to calculate the electrical conductivity of natural waters from its chemical composition. He is currently involved in several research projects in Yellowstone National Park, a wildfire affected watershed, and acid mine drainage sites.
Education
B.S. - Biochemistry, College of Charleston, SC, 1995
M.S. - Environmental Studies (Science track), University of Charleston, SC, 1997
Ph.D. - Environmental Engineering (Hydrologic Sciences Program), University of Colorado, 2010
Blaine McCleskey also runs and maintains the USGS Redox Chemistry Laboratory, where analytical methods for determining the redox distributions of iron, arsenic, chromium, and antimony have been developed (see puplished methods below). In addition, the lab supports many USGS projects by providing iron, arsenic, chromium, antimony, and selenium redox determinations. The lab is equipped with an ICP-AES, IC, GFAAS, HGAAS, UV-VIS spectrophotometer, and an autotitrator and we are capable of determining most inorganic constituents and specialize in difficult matrices (acid mine waters, geothermal waters, and saline waters).
Science and Products
Water Chemistry Data for Selected Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, Beginning 2009
Results of water analyses conducted on numerous thermal and non-thermal features in Yellowstone National Park beginning in 2009. Water samples were collected and analyzed as part of research investigations on arsenic, iron, nitrogen, and sulfur redox species in hot springs and overflow drainages; the occurrence and distribution of dissolved mercury; and general hydrogeochemistry of hot springs.
Filter Total Items: 15
Water-quality results from a wastewater reuse study: Inorganic and organic compositions of wastewater effluent and select urban and agricultural water types during rain-induced runoff, Chickasha, Oklahoma, 2018-2019
Oklahoma State University South-Central Research Station (SCRS) was used to conduct research to understand the chemical composition of various water types and their potential environmental and human health effects. The study area provided the opportunity to study five water types: (1) receiving surface water (Washita River), (2) urban stormwater, (3) wastewater treatment plant effluent used for ir
Inorganic Concentration Results for Assessment of Mixed Organic/Inorganic Chemical and Biological Exposures in North Dakota and South Dakota Tapwater, 2019
This data set reports results for inorganic constituents analyzed at the Redox Chemistry Laboratory in Boulder, Colorado, for the 2019 tapwater study conducted in North Dakota and South Dakota, USA. This project is part of the U.S. Geological Survey, Ecosystems Mission Area, Environmental Health Water and Wastewater Infrastructure Program.
Concentrations of organic and inorganic constituents in tapwater samples from California in 2020-21
This dataset contains the trace elements, cations, anions, and disinfection by-products concentration results for the tapwater study conducted in California, November, 2020 through May, 2021. Trace elements, cations and anions were analyzed at the U.S. Geological Survey Redox Chemistry Laboratory in Boulder, Colorado. The disinfection by-product compounds were analyzed at the U.S. Geological Surve
Isotopic Examination of Mercury Methylation and Demethylation Rates in Yellowstone National Park Thermal Features
Data in this data release were obtained for water samples collected under Yellowstone National Park Research Permit YELL-05194 in 2017 through the Integrated Yellowstone Studies Project funded by the Mineral Resources Program. Isotope-spiked incubations were carried out to determine methylation and demethylation potential for Frying Pan spring, Crystal Sister East, Crystal Sister West, and Turbule
Yellowstone Thermal Feature Mercury and Methylmercury Characterization
Data in this data release were obtained from water samples collected under Yellowstone National Park (YNP) Research Permit YELL-05194 in 2017, 2019, and 2020 through the Integrated Yellowstone Studies Project funded by the Mineral Resources Program. These samples were used to assess mercury cycling within YNP. Water samples were analyzed for total mercury and methylmercury, the bioaccumulated form
Temporal Viral Viability Data from Avian Influenza A Viruses Maintained in Alaska Wetlands Under Experimental and Environmental Conditions
Data sets containing: (1) sample collection and influenza A virus (IAV) screening information for wild ducks, (2) water temperature data from four wetlands within the Izembek National Wildlife Refuge in Alaska, USA (3) water quality measurement from four wetlands within the Izembek National Wildlife Refuge in Alaska, USA, (4) genetic sequence data for IAVs recovered from replicate samples of wild
Streamflow and water chemistry in the Tenaya Lake Basin, Yosemite National Park, California
The Tenaya Lake Water Budget Study seeks to quantify and understand the water balance within the principal snow accumulation and runoff yielding zone in the Sierra Nevada Mountains. The Study operates stage sensors and data loggers to record Tenaya Lake inflows, water surface elevation, and outflow, with continuous annual data collection for the 21 square-kilometer watershed located in the alpine
Groundwater chemistry in the Lower East Rift Zone and summit of Kilauea Volcano, Hawai'i
Chemical and isotopic analyses are reported for water samples collected from water supply wells, a geothermal well in the Puna Geothermal Venture (PGV) power plant, a hot spring in the Puna District, a research well on the summit of Kilauea Volcano (informally called "NSF Well", or "Keller Well "), and a water catchment in the headquarters area of Hawai'i Volcanoes National Park, Hawai'i. These wa
Chemistry of water, stream sediment, wildfire ash, soil, dust, and mine waste for Fourmile Creek Watershed, Colorado, 2010-2019
In response to the 2010 Fourmile Canyon fire near Boulder, Colorado, the U.S. Geological Survey collected data to support investigations into the magnitude and critical drivers of water-quality impairment after wildfire. We analyzed chemistry of stream water, sediment, wildfire ash, soil, dust, and mine waste for metals and other parameters in order to evaluate the effects of legacy mining and wil
Specific conductance data for selected rivers and creeks in Yellowstone National Park, beginning in 2010 (version 2.0, May 2020)
Monitoring the chloride (Cl) flux in the major rivers draining Yellowstone National Park (YNP) provides a holistic view of the thermal output from the underlying magma reservoir, and abrupt fluctuations in the Cl flux may signify changes in hydrothermal activity. The U.S. Geological Survey (USGS) and the National Park Service (NPS) have collaborated on Cl flux monitoring of the major rivers since
Water chemistry data for selected hot springs and rivers in Southwest Yellowstone National Park, Wyoming
Water analyses are reported for 66 samples collected from numerous thermal and non-thermal (rivers and streams) features in the southwestern areas of Yellowstone National Park (YNP) during 2009, 2017, and 2018. Water samples were collected from sources near Boundary Creek, Bechler River, Falls River, Mountain Ash Creek, Upper Snake River, Spirea Creek, and Lewis Lake. These water samples were coll
Occurrence and Concentrations of Trace Elements in Discrete Tapwater Samples Collected in Chicago, Illinois and East Chicago, Indiana, 2017
This dataset contains the trace element concentration results for samples collected from tapwater sites in East Chicago, Indiana, August-September, 2017, and Chicago, Illinois, July-December, 2017. Samples were collected one time, from 45 private residences and associated drinking water plants and source water locations. Water-quality samples were analyzed at two U.S. Geological Survey laboratorie
Filter Total Items: 83
Food, beverage, and feedstock processing facility wastewater: A unique and underappreciated source of contaminants to U.S. streams
Process wastewaters from food, beverage, and feedstock facilities, although regulated, are an under-investigated environmental contaminant source. Food process wastewaters (FPWWs) from 23 facilities in 17 U.S. states were sampled and documented for a plethora of chemical and microbial contaminants. Of the 576 analyzed organics, 184 (32%) were detected at least once, with concentrations as large as
By
Ecosystems, Water Resources, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Central Midwest Water Science Center, Kansas Water Science Center, New Jersey Water Science Center, Pennsylvania Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality Laboratory
Quantifying non-thermal silicate weathering using Ge/Si and Si isotopes in rivers draining the Yellowstone Plateau Volcanic Field, USA
In active volcanic regions, high-temperature chemical reactions in the hydrothermal system consume CO2 sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO2. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO2 consumption
The structure and volume of large geysers in Yellowstone National Park, USA and the mineralogy and chemistry of their silica sinter deposits
Siliceous sinter is formed by biogenic and abiogenic opal deposition around hot springs and geysers. Using Structure-from-Motion photogrammetry we generated three-dimensional models of Giant and Castle Geysers from the Upper Geyser Basin of Yellowstone National Park. We use these models to calculate an approximate mass of sinter for each (~2 and ~ 5 kton, respectively) and estimate a range of plau
Evidence for interannual persistence of infectious influenza A viruses in Alaska wetlands
Influenza A viruses (IAVs) deposited by wild birds into the environment may lead to sporadic mortality events and economically costly outbreaks among domestic birds. There is a paucity of information, however, regarding the persistence of infectious IAVs within the environment following deposition. In this investigation, we assessed the persistence of 12 IAVs that were present in the cloaca and/or
Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of than 524 organic, 37 inorganic, and select microbiolo
The systematics of chlorine, lithium, and boron and δ37Cl, δ7Li, and δ11B in the hydrothermal system of the Yellowstone Plateau Volcanic Field
Chlorine, lithium, and boron are trace elements in rhyolite but are enriched in groundwater flowing through rhyolite because they tend to partition into the fluid phase during high‐temperature fluid‐rock reactions. We present a large data set of major element and δ37Cl, δ7Li, and δ11B compositions of thermal water and rhyolite from Yellowstone Plateau Volcanic Field (YPVF). The Cl/B, Cl/Li, δ37Cl
Public and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA
BackgroundHumans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures and risks between private- and public-supplies under
By
Ecosystems, Water Resources, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Eastern Ecological Science Center, New England Water Science Center, New Jersey Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality Laboratory
Sources, fate, and flux of riverine solutes in the Southwest Yellowstone Plateau Volcanic Field, USA
Since the 1970s, temporal variations of hydrothermal discharge and thermal output from the numerous hydrothermal features in the Yellowstone Plateau Volcanic Field (YPVF) have been studied by measuring the chloride flux in the major rivers. In this study, the sources, fate, and flux of solutes in the Fall River and its major tributaries, in southwest Yellowstone National Park, were determined. The
Wildfire-driven changes in hydrology mobilize arsenic and metals from legacy mine waste
Wildfires burning in watersheds that have been mined and since revegetated pose unique risks to downstream water supplies. A wildfire near Boulder, Colorado that burned a forested watershed recovering from mining disturbance that occurred 80-160 years ago allowed us to 1) assess arsenic and metal contamination in streams draining the burned area for a five-year period after the wildfire and 2) det
Hydrothermal activity in the southwest Yellowstone Plateau Volcanic Field
In the past two decades, the U.S. Geological Survey and the National Park Service have studied hydrothermal activity across the Yellowstone Plateau Volcanic Field (YPVF) to improve the understanding of the magmatic-hydrothermal system and to provide a baseline for detecting future anomalous activity. In 2017 and 2018 we sampled water and gas over a large area in the southwest YPVF and used Landsat
Mixed organic and inorganic tapwater exposures and potential effects in greater Chicago area, USA
Safe drinking water at the point of use (tapwater, TW) is a public-health priority. TW exposures and potential human-health concerns of 540 organics and 35 inorganics were assessed in 45 Chicago area United States (US) homes in 2017. No US Environmental Protection Agency (EPA) enforceable Maximum Contaminant Level(s) (MCL) were exceeded in any residential or water treatment plant (WTP) pre-distrib
Sources, fate, and flux of geothermal solutes in the Yellowstone and Gardner Rivers, Yellowstone National Park, WY
The total discharge and thermal output from the numerous hydrothermal features in Yellowstone National Park (YNP) can be estimated from the chloride (Cl) flux in the Madison, Yellowstone, Falls, and Snake Rivers. Monitoring the Cl flux in these four major rivers provides a holistic view of the hydrothermal output from YNP and changes in the Cl flux may indicate changes in geothermal or magmatic ac
Science and Products
- Science
Water Chemistry Data for Selected Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, Beginning 2009
Results of water analyses conducted on numerous thermal and non-thermal features in Yellowstone National Park beginning in 2009. Water samples were collected and analyzed as part of research investigations on arsenic, iron, nitrogen, and sulfur redox species in hot springs and overflow drainages; the occurrence and distribution of dissolved mercury; and general hydrogeochemistry of hot springs. - Data
Filter Total Items: 15
Water-quality results from a wastewater reuse study: Inorganic and organic compositions of wastewater effluent and select urban and agricultural water types during rain-induced runoff, Chickasha, Oklahoma, 2018-2019
Oklahoma State University South-Central Research Station (SCRS) was used to conduct research to understand the chemical composition of various water types and their potential environmental and human health effects. The study area provided the opportunity to study five water types: (1) receiving surface water (Washita River), (2) urban stormwater, (3) wastewater treatment plant effluent used for irInorganic Concentration Results for Assessment of Mixed Organic/Inorganic Chemical and Biological Exposures in North Dakota and South Dakota Tapwater, 2019
This data set reports results for inorganic constituents analyzed at the Redox Chemistry Laboratory in Boulder, Colorado, for the 2019 tapwater study conducted in North Dakota and South Dakota, USA. This project is part of the U.S. Geological Survey, Ecosystems Mission Area, Environmental Health Water and Wastewater Infrastructure Program.Concentrations of organic and inorganic constituents in tapwater samples from California in 2020-21
This dataset contains the trace elements, cations, anions, and disinfection by-products concentration results for the tapwater study conducted in California, November, 2020 through May, 2021. Trace elements, cations and anions were analyzed at the U.S. Geological Survey Redox Chemistry Laboratory in Boulder, Colorado. The disinfection by-product compounds were analyzed at the U.S. Geological SurveIsotopic Examination of Mercury Methylation and Demethylation Rates in Yellowstone National Park Thermal Features
Data in this data release were obtained for water samples collected under Yellowstone National Park Research Permit YELL-05194 in 2017 through the Integrated Yellowstone Studies Project funded by the Mineral Resources Program. Isotope-spiked incubations were carried out to determine methylation and demethylation potential for Frying Pan spring, Crystal Sister East, Crystal Sister West, and TurbuleYellowstone Thermal Feature Mercury and Methylmercury Characterization
Data in this data release were obtained from water samples collected under Yellowstone National Park (YNP) Research Permit YELL-05194 in 2017, 2019, and 2020 through the Integrated Yellowstone Studies Project funded by the Mineral Resources Program. These samples were used to assess mercury cycling within YNP. Water samples were analyzed for total mercury and methylmercury, the bioaccumulated formTemporal Viral Viability Data from Avian Influenza A Viruses Maintained in Alaska Wetlands Under Experimental and Environmental Conditions
Data sets containing: (1) sample collection and influenza A virus (IAV) screening information for wild ducks, (2) water temperature data from four wetlands within the Izembek National Wildlife Refuge in Alaska, USA (3) water quality measurement from four wetlands within the Izembek National Wildlife Refuge in Alaska, USA, (4) genetic sequence data for IAVs recovered from replicate samples of wildStreamflow and water chemistry in the Tenaya Lake Basin, Yosemite National Park, California
The Tenaya Lake Water Budget Study seeks to quantify and understand the water balance within the principal snow accumulation and runoff yielding zone in the Sierra Nevada Mountains. The Study operates stage sensors and data loggers to record Tenaya Lake inflows, water surface elevation, and outflow, with continuous annual data collection for the 21 square-kilometer watershed located in the alpineGroundwater chemistry in the Lower East Rift Zone and summit of Kilauea Volcano, Hawai'i
Chemical and isotopic analyses are reported for water samples collected from water supply wells, a geothermal well in the Puna Geothermal Venture (PGV) power plant, a hot spring in the Puna District, a research well on the summit of Kilauea Volcano (informally called "NSF Well", or "Keller Well "), and a water catchment in the headquarters area of Hawai'i Volcanoes National Park, Hawai'i. These waChemistry of water, stream sediment, wildfire ash, soil, dust, and mine waste for Fourmile Creek Watershed, Colorado, 2010-2019
In response to the 2010 Fourmile Canyon fire near Boulder, Colorado, the U.S. Geological Survey collected data to support investigations into the magnitude and critical drivers of water-quality impairment after wildfire. We analyzed chemistry of stream water, sediment, wildfire ash, soil, dust, and mine waste for metals and other parameters in order to evaluate the effects of legacy mining and wilSpecific conductance data for selected rivers and creeks in Yellowstone National Park, beginning in 2010 (version 2.0, May 2020)
Monitoring the chloride (Cl) flux in the major rivers draining Yellowstone National Park (YNP) provides a holistic view of the thermal output from the underlying magma reservoir, and abrupt fluctuations in the Cl flux may signify changes in hydrothermal activity. The U.S. Geological Survey (USGS) and the National Park Service (NPS) have collaborated on Cl flux monitoring of the major rivers sinceWater chemistry data for selected hot springs and rivers in Southwest Yellowstone National Park, Wyoming
Water analyses are reported for 66 samples collected from numerous thermal and non-thermal (rivers and streams) features in the southwestern areas of Yellowstone National Park (YNP) during 2009, 2017, and 2018. Water samples were collected from sources near Boundary Creek, Bechler River, Falls River, Mountain Ash Creek, Upper Snake River, Spirea Creek, and Lewis Lake. These water samples were collOccurrence and Concentrations of Trace Elements in Discrete Tapwater Samples Collected in Chicago, Illinois and East Chicago, Indiana, 2017
This dataset contains the trace element concentration results for samples collected from tapwater sites in East Chicago, Indiana, August-September, 2017, and Chicago, Illinois, July-December, 2017. Samples were collected one time, from 45 private residences and associated drinking water plants and source water locations. Water-quality samples were analyzed at two U.S. Geological Survey laboratorie - Publications
Filter Total Items: 83
Food, beverage, and feedstock processing facility wastewater: A unique and underappreciated source of contaminants to U.S. streams
Process wastewaters from food, beverage, and feedstock facilities, although regulated, are an under-investigated environmental contaminant source. Food process wastewaters (FPWWs) from 23 facilities in 17 U.S. states were sampled and documented for a plethora of chemical and microbial contaminants. Of the 576 analyzed organics, 184 (32%) were detected at least once, with concentrations as large asByEcosystems, Water Resources, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Central Midwest Water Science Center, Kansas Water Science Center, New Jersey Water Science Center, Pennsylvania Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality LaboratoryQuantifying non-thermal silicate weathering using Ge/Si and Si isotopes in rivers draining the Yellowstone Plateau Volcanic Field, USA
In active volcanic regions, high-temperature chemical reactions in the hydrothermal system consume CO2 sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO2. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO2 consumptionThe structure and volume of large geysers in Yellowstone National Park, USA and the mineralogy and chemistry of their silica sinter deposits
Siliceous sinter is formed by biogenic and abiogenic opal deposition around hot springs and geysers. Using Structure-from-Motion photogrammetry we generated three-dimensional models of Giant and Castle Geysers from the Upper Geyser Basin of Yellowstone National Park. We use these models to calculate an approximate mass of sinter for each (~2 and ~ 5 kton, respectively) and estimate a range of plauEvidence for interannual persistence of infectious influenza A viruses in Alaska wetlands
Influenza A viruses (IAVs) deposited by wild birds into the environment may lead to sporadic mortality events and economically costly outbreaks among domestic birds. There is a paucity of information, however, regarding the persistence of infectious IAVs within the environment following deposition. In this investigation, we assessed the persistence of 12 IAVs that were present in the cloaca and/orPilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of than 524 organic, 37 inorganic, and select microbioloThe systematics of chlorine, lithium, and boron and δ37Cl, δ7Li, and δ11B in the hydrothermal system of the Yellowstone Plateau Volcanic Field
Chlorine, lithium, and boron are trace elements in rhyolite but are enriched in groundwater flowing through rhyolite because they tend to partition into the fluid phase during high‐temperature fluid‐rock reactions. We present a large data set of major element and δ37Cl, δ7Li, and δ11B compositions of thermal water and rhyolite from Yellowstone Plateau Volcanic Field (YPVF). The Cl/B, Cl/Li, δ37ClPublic and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA
BackgroundHumans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures and risks between private- and public-supplies underByEcosystems, Water Resources, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Eastern Ecological Science Center, New England Water Science Center, New Jersey Water Science Center, South Atlantic Water Science Center (SAWSC), Upper Midwest Water Science Center, National Water Quality LaboratorySources, fate, and flux of riverine solutes in the Southwest Yellowstone Plateau Volcanic Field, USA
Since the 1970s, temporal variations of hydrothermal discharge and thermal output from the numerous hydrothermal features in the Yellowstone Plateau Volcanic Field (YPVF) have been studied by measuring the chloride flux in the major rivers. In this study, the sources, fate, and flux of solutes in the Fall River and its major tributaries, in southwest Yellowstone National Park, were determined. TheWildfire-driven changes in hydrology mobilize arsenic and metals from legacy mine waste
Wildfires burning in watersheds that have been mined and since revegetated pose unique risks to downstream water supplies. A wildfire near Boulder, Colorado that burned a forested watershed recovering from mining disturbance that occurred 80-160 years ago allowed us to 1) assess arsenic and metal contamination in streams draining the burned area for a five-year period after the wildfire and 2) detHydrothermal activity in the southwest Yellowstone Plateau Volcanic Field
In the past two decades, the U.S. Geological Survey and the National Park Service have studied hydrothermal activity across the Yellowstone Plateau Volcanic Field (YPVF) to improve the understanding of the magmatic-hydrothermal system and to provide a baseline for detecting future anomalous activity. In 2017 and 2018 we sampled water and gas over a large area in the southwest YPVF and used LandsatMixed organic and inorganic tapwater exposures and potential effects in greater Chicago area, USA
Safe drinking water at the point of use (tapwater, TW) is a public-health priority. TW exposures and potential human-health concerns of 540 organics and 35 inorganics were assessed in 45 Chicago area United States (US) homes in 2017. No US Environmental Protection Agency (EPA) enforceable Maximum Contaminant Level(s) (MCL) were exceeded in any residential or water treatment plant (WTP) pre-distribSources, fate, and flux of geothermal solutes in the Yellowstone and Gardner Rivers, Yellowstone National Park, WY
The total discharge and thermal output from the numerous hydrothermal features in Yellowstone National Park (YNP) can be estimated from the chloride (Cl) flux in the Madison, Yellowstone, Falls, and Snake Rivers. Monitoring the Cl flux in these four major rivers provides a holistic view of the hydrothermal output from YNP and changes in the Cl flux may indicate changes in geothermal or magmatic ac