Time-series measurements of acoustic intensity, flow, pressure, water level, conductivity, temperature, and dissolved oxygen collected in a flooded cave at Cenote Bang, Yucatan Peninsula, Tulum, Mexico from March 25, 2018 to August 1, 2018

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Suttles, Steven E, Ganju, Neil K, Brankovits, David, and Pohlman, John W, 20240423, Time-series measurements of acoustic intensity, flow, pressure, water level, conductivity, temperature, and dissolved oxygen collected in a flooded cave at Cenote Bang, Yucatan Peninsula, Tulum, Mexico from March 25, 2018 to August 1, 2018: data release https://doi.org/10.5066/P1CRRF88, U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

   Online Links:

   • https://doi.org/10.5066/P1CRRF88
   • https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P1CRRF88/

   Other_Citation_Details:

   Suggested citation: Suttles, S.E., Ganju, N.K., Brankovits, D., and Pohlman, J.W., 2024, Time-series measurements of acoustic intensity, flow, pressure, water level, conductivity,temperature, and dissolved oxygen collected in a flooded cave at Cenote Bang, Yucatan Peninsula, Tulum, Mexico from March 25, 2018 to August 1, 2018: U.S. Geological Survey data release, https://doi.org/10.5066/P1CRRF88.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -87.56930
   East_Bounding_Coordinate: -87.41656
   North_Bounding_Coordinate: 20.28294
   South_Bounding_Coordinate: 20.10842
   

3. What does it look like?

   https://cmgds.marine.usgs.gov/data-releases/media/2024/10.5066-P1CRRF88/29178cf1819d40e88785e6404d0c0012/cavemx18_deploy_dive.jpg (JPEG)

   Divers deploying an instrumented platform in a cave near Tulum, MX in March 2018.

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 25-Mar-2018

   Ending_Date: 01-Aug-2018

   Currentness_Reference:

   ground condition at time data were collected

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: netCDF files
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      

      Indirect_Spatial_Reference:

      Data were collected continuously at each sensor. Refer to self-describing netCDF files for more location information.

      This is a Raster data set.
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is World Geodetic System (WGS) of 1984.
      The ellipsoid used is WGS_84.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: Local height above cave floor
      Altitude_Resolution: 0.1
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:

      Explicit elevation coordinate included with horizontal coordinates

      Depth_System_Definition:

      Depth_Datum_Name: Local water table
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   NetCDF files are self-describing and attribute information may be found in the header of the file itself.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Steven E Suttles
   • Neil K Ganju
   • David Brankovits
   • John W Pohlman
2. Who also contributed to the data set?
   We wish to acknowledge Jake Emmert, diving safety officer at Moody Gardens Aquarium, for assistance with field work for this project.
3. To whom should users address questions about the data?
   Steven E Suttles

   U.S. Geological Survey, Northeast Region

   Mechanical Engineer

   384 Woods Hole Road

   Woods Hole, MA
   

   US

   508-458-8700 (voice)

   whsc_data_contact@usgs.gov

   Contact_Instructions:

   The contact email address is a generic address in the event the person is no longer with USGS.

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 01-Aug-2018 (process 1 of 2)

   Beginning on March 25, 2018, instruments to measure time-series data of water quality, water level, flow velocity, and mixing between water masses within flooded coastal cave passages were deployed at four locations in the Ox Bel Ha Cave System, accessed through the sinkhole Cenote Bang approximately 6.3 km inland, just south of Tulum (Quintana Roo, Mexico). The instruments were deployed in the cave environment by SCUBA divers who followed protocols established by the USGS, American Academy of Underwater Sciences, and the National Speleological Society Cave Diving Section. A dissolved oxygen sensor was deployed in the entrance sinkhole pool. A fiberglass platform containing an acoustic doppler current profiler (Nortek Aquadopp) and buoys to achieve positive buoyancy was installed on the cave ceiling at approximately 3.5 m water depth in freshwater approximately 20 m horizontal distance from the entrance sinkhole pool. Next to the fiberglass platform, at the same depth, a HOBO dissolved oxygen sensor was co-deployed with an OsmoSampler and packed in a plastic box (42 cm wide, 42 cm long, and 33 cm high) to allow the diver to safely deploy the full set of devices. In the same location, but below a halocline at 7.5 m water depth in the brackish water, another set of equipment (including loggers measuring dissolved oxygen, conductivity, and water level) was co-deployed with an OsmoSampler in another plastic box. Approximately 100 m upstream and westward in the main passage from these instruments, the following set of instruments were co-deployed after a northern curvature in the passage at 21 m water depth in completely saline water; EA400 acoustic profiler, a water level logger, and a dissolved oxygen logger. In the vicinity of this bundle, tilt-current meters (TCMs) were deployed at 17 m and 22 m water depth using lead dive weights to anchor them on the rocky bottom. In addition, a barometric pressure gauge was deployed on the surface on a roof of a house approximately 15 m above the ground. All deployed sensors were recovered on August 1, 2018, using divers for all submerged sensors. Upon recovery, the data were retrieved from the instruments, archived for safe keeping, and made available for processing. The OsmoSampler time-series is not part of this release.

   Date: Apr-2024 (process 2 of 2)

   Data from the HOBO and TCM loggers were downloaded in csv format using dedicated software provided by the two companies. Where it was needed, barometric data that was obtained from the pressure logger deployed on the surface was used to correct the time-series data downloaded from the HOBO loggers using the HOBO software. The raw or vendor post-processed data files from each sensor were processed and converted to netCDF using stglib python libraries, a package of code to process data consistent with procedures of the USGS Coastal and Marine Hazards and Resources Program. In stglib, attributes conforming to Climate and Forecast (CF) Conventions version 1.8 were added. All times are in Coordinated Universal Time (UTC). Data quality assurance and quality control (QAQC) was performed by inspecting all variables and replacing spurious values with the fill value. Details of which portions of data were flagged and replaced are available in the metadata in each netCDF file and information about the individual QAQC trimming functions are available in the stglib documentation (https://stglib.readthedocs.io/en/latest/) in the "Instrument configuration file" section. The netCDF files are named using the convention ####XZZZ-a.nc where '####' is the mooring number, 'X' is the position on the mooring of the sensor with 1 being closest to the surface, and 'ZZZ' is a 2 or 3 character abbreviation for the instrument that was deployed. For example, in the file 11141ea-a.nc, '1114' is the mooring number, '1' is the position of the sensor on the mooring, and 'ea' refers to the Echologger EA400 sensor. The '-a' refers to Best Basic Version (BBV) of the processed data.

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   Sensor specifications were obtained from the manufacture/vendor of each instrument used and are as follows; EchoLogger EA400 altimeter has a water column resolution of 7.5 mm, range resolution of 1 mm, temperature accuracy of ±0.5 degrees C, and tilt sensor inclination accuracy of ±0.1 degrees. The Nortek Aquadopp High Resolution (HR) acoustic doppler current profiler (ADCP) has a water velocity accuracy of ±1% of measured value or ±0.5 cm/s, a heading and tilt accuracy of ±2 degrees and resolution of 0.1 degree, a pressure accuracy of ±0.5% of full scale (FS) with resolution of 0.005% FS, an echo intensity resolution of 0.45 dB, and a temperature sensor accuracy of 0.1 degrees C with a 10 min response time. HOBO water level/pressure loggers (U20L-02) have an accuracy/max error of ±0.2% FS, or 0.06 m of water and raw pressure accuracy of ±0.3% FS or 1.20 kPa, and companion temperature data accuracy of ±0.44 degrees C from 0-50 degrees C; dissolved oxygen loggers (U26-001) have an accuracy of ±0.2 mg/l up to 8 mg/l and ±0.5 mg/l from 8 to 20 mg/l with a resolution of 0.02 mg/l, and companion temperature data accuracy of ± 0.2 degrees C; and conductivity loggers (U-24) have a specific conductance accuracy of 3% of reading or 5 micro-siemens(uS)/cm for low range (0-2,500 uS/cm) and 20 uS/cm for full range (0 - 15,000 uS/cm), and temperature accuracy of 0.1 at 25 degrees C. Tilt Current Meters (TCMs) have water speed accuracy of 2 cm/s + 3% of reading with a 0.1 cm/s resolution, and direction accuracy of 5 degrees (for speed >5 cm/s) with a 0.1 degree resolution.
2. How accurate are the geographic locations?
   A Garmin GPSmap 60CSx handheld Global Positioning System (GPS) was used to collect horizontal location data. The GPS has an expected accuracy of ±3 m at best. For reported horizontal positions, the World Geodetic System of 1984 (WGS84) reference frame was used. Locations for the deployed instruments in the caves were estimated using GPS obtained coordinates at the cave entry location and estimates of diver distance traveled horizontally and vertically in the cave from the fixed lines that have been installed in the cave and the available maps of the underground cave network. Google Earth was then used to get the estimated latitude and longitude coordinates of the deployment locations in the cave. The expected accuracy of these locations in the cave is approximately ±30 meters.
3. How accurate are the heights or depths?
   Vertical positions were obtained using diver estimated depths below local ground water table at the time of deployment for instruments in the cave and height measurements above ground level for instruments deployed in air. Depths below water table were confirmed using the diver’s depth gauge and the deployed water level sensors and adjusted as needed. Vertical heights above the cave floor were determined by direct measurements when deployed near the cave floor, and by the difference of total water depth and sensor depth when deployed higher up in the water column. Estimates of vertical positions are expected to have accuracy of ~ 0.30 m from local water table at time of deployment, or ground elevation for atmospheric pressure data. No fixed datum vertical positions were available for this data set.
4. Where are the gaps in the data? What is missing?
   All velocity data from the cave ceiling mounted Nortek Aquadopp HR profiler was deemed not usable due to challenges using doppler acoustic instruments in this cave environment, those data were replaced with fill values, the acoustic intensity data was useful and it is provided in this data set. A ceiling mounted, downward looking EA400 Echologger leaked and failed before the start of the deployment and therefore did not provide any data. Similarly, a rain gauge sensor that was deployed near the cave entrance failed and did not collect any usable data.
5. How consistent are the relationships among the observations, including topology?
   : Barometric pressure data obtained from a HOBO pressure logger deployed in air at mooring 1171 was used to correct the time-series data downloaded from the submerged HOBO loggers using the HOBO software. A derived sensor depth variable was created for the HOBO water-level loggers in the exported comma separated variables (csv) files. For pressure data from the Nortek Aquadopp HR, pressure sensor data was compared to the in-air HOBO barometric pressure data before deployment and an offset was determined. This offset along with the time-series of local barometric pressure data were used to find corrected pressure data (variable name "P_1ac" and standard_name "sea_water_pressure_due_to_sea_water" in the netCDF files) All data were processed and converted into netCDF files with processing code from stglib, a package of code to process data consistent with procedures of the USGS Coastal and Marine Hazards and Resources Program. More information about the stglib package can be found here: https://stglib.readthedocs.io/en/latest/.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   Steven E Suttles

   U.S. Geological Survey, Northeast Region

   Mechanical Engineer

   384 Woods Hole Road

   Woods Hole, MA
   

   US

   508-548-8700 (voice)

   whsc_data_contact@usgs.gov

   Contact_Instructions:

   The contact email address is a generic address in the event the person is no longer with USGS.

2. What's the catalog number I need to order this data set? Downloadable data in netCDF format. NetCDF files are named by site location code and deployment sequence at each site. There are 14 processed netCDF files in this dataset.
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Time-series data in netCDF format following Climate and Forecast (CF) Metadata Conventions version 1.8. File download sizes range from 0.4 to 1,108 MB. in format netCDF (version netCDF-4, CF-1.8) Size: 1108
     Network links:	https://cmgds.marine.usgs.gov/data-releases/media/2024/10.5066-P1CRRF88/5b277a9db6cd45828b9319a2492fe2d4/cavemx_timeseries_ncfiles.zip https://doi.org/10.5066/P1CRRF88

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   These data can be viewed with any software capable of reading netCDF files.

Who wrote the metadata?

Dates:

Last modified: 23-Apr-2024

Metadata author:

Steven E Suttles

U.S. Geological Survey, Northeast Region

Mechanical Engineer

384 Woods Hole Road

Woods Hole, MA

US

508-548-8700 (voice)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the person is no longer with USGS.

Metadata standard:

FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)