In the laboratory, water samples were filtered (0.2 μm polysulfone GD/X) and
separated into subsamples for analysis of cations, anions, alkalinity, dissolved
organic carbon (DOC), and dissolved inorganic carbon (DIC) and water isotopes.
Cation samples were preserved with HNO 3 and analyzed for Al, Ca, K, Mg, Na, Si,
and Sr via inductively coupled plasma atomic emission spectrometry. Anion samples were analyzed for Cl, NO 3 , and SO 4 via ion chromatography. Alkalinity was
determined using Gran titration [29]. DOC samples were preserved with HCl and
analyzed via catalytic oxidation. Samples for stable carbon isotopic composition
(δ
13 C) of DIC were collected without headspace in vials sealed with low-diffusion
butyl rubber septa and were preserved with copper sulfate. Analysis of the δ
13 CDIC was conducted at the Reston Stable Isotope Laboratory of the US Geological
Survey [30]. Liquid water stable isotopes (δD and δ
18 O) were analyzed using a
liquid water isotope analyzer at Texas State University-San Marcos.
5 Data Collection and Management
5.1 Data Recording and Downloading
Nearly continuous time series data are recorded at 10-min intervals and data are
stored either on the equipment or on separate data loggers. Instruments with internal
storage include the SCT loggers, the pressure transducers, and the barometric
pressure loggers. Instruments with external data storage devices include rain gauges
and air temperature and temperature/relative humidity sensors.
Time series data are downloaded on monthly or bimonthly intervals. Because of
the range of instrumentation, there is an associated range of software that has been
used at the James Cave site both to offload data from loggers and to post-process
data. Software that we used at the start of the project included (a) HOBOware for
Onset instrumentation,
1 (b) Hanna Instruments software for Hanna instrumentation,
and (c) Level Logger software for Solinst pressure transducers. With the aforementioned changes in instrumentation, HOBOware is the only software currently
(2014) needed to program and download data from all cave instruments.
5.2 Data Processing
Data collected by a variety of instruments and methods may result in data in a
variety of units and formats, requiring consistent naming conventions and clearly
outlined data processing procedures. Eagle [21] outlines the data management and
processing procedures used for the James Cave project. Initially, for the project,
1 The use of product or trade names is for descriptive purposes only and does not constitute
endorsement by the US government.
222
M.E. Schreiber et al.
separated into subsamples for analysis of cations, anions, alkalinity, dissolved
organic carbon (DOC), and dissolved inorganic carbon (DIC) and water isotopes.
Cation samples were preserved with HNO 3 and analyzed for Al, Ca, K, Mg, Na, Si,
and Sr via inductively coupled plasma atomic emission spectrometry. Anion samples were analyzed for Cl, NO 3 , and SO 4 via ion chromatography. Alkalinity was
determined using Gran titration [29]. DOC samples were preserved with HCl and
analyzed via catalytic oxidation. Samples for stable carbon isotopic composition
(δ
13 C) of DIC were collected without headspace in vials sealed with low-diffusion
butyl rubber septa and were preserved with copper sulfate. Analysis of the δ
13 CDIC was conducted at the Reston Stable Isotope Laboratory of the US Geological
Survey [30]. Liquid water stable isotopes (δD and δ
18 O) were analyzed using a
liquid water isotope analyzer at Texas State University-San Marcos.
5 Data Collection and Management
5.1 Data Recording and Downloading
Nearly continuous time series data are recorded at 10-min intervals and data are
stored either on the equipment or on separate data loggers. Instruments with internal
storage include the SCT loggers, the pressure transducers, and the barometric
pressure loggers. Instruments with external data storage devices include rain gauges
and air temperature and temperature/relative humidity sensors.
Time series data are downloaded on monthly or bimonthly intervals. Because of
the range of instrumentation, there is an associated range of software that has been
used at the James Cave site both to offload data from loggers and to post-process
data. Software that we used at the start of the project included (a) HOBOware for
Onset instrumentation,
1 (b) Hanna Instruments software for Hanna instrumentation,
and (c) Level Logger software for Solinst pressure transducers. With the aforementioned changes in instrumentation, HOBOware is the only software currently
(2014) needed to program and download data from all cave instruments.
5.2 Data Processing
Data collected by a variety of instruments and methods may result in data in a
variety of units and formats, requiring consistent naming conventions and clearly
outlined data processing procedures. Eagle [21] outlines the data management and
processing procedures used for the James Cave project. Initially, for the project,
1 The use of product or trade names is for descriptive purposes only and does not constitute
endorsement by the US government.
222
M.E. Schreiber et al.