Near-shore seawater-column measurements of excess radon (Rn-222) and water levels, Faga'alu Bay, Tutuila, American Samoa, August 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?
   Oberle, Ferdinand K.J., Prouty, Nancy G., and Storlazzi, Curt D., 20210520, Near-shore seawater-column measurements of excess radon (Rn-222) and water levels, Faga'alu Bay, Tutuila, American Samoa, August 2018: data release DOI:10.5066/P9F0LJNC, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9F0LJNC
   • https://www.sciencebase.gov/catalog/item/6074f9a3d34e018b31fff905

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -170.68171
   East_Bounding_Coordinate: -170.68070
   North_Bounding_Coordinate: -14.28889
   South_Bounding_Coordinate: -14.28986
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 09-Aug-2018

   Ending_Date: 12-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: comma-delimited text
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (195)
   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 D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      
7. How does the data set describe geographic features?

   ASCII Table

   Comma-delimited ASCII table of a point measurement of groundwater excess radon. (Source: Producer defined)

   Date

   Date and time referenced to Universal Coordinated Time (Source: Global Positioning System)

   Range of values
   Minimum:	2018/08/09 23:38:00
   Maximum:	2018/08/12 01:27:00
   Units:	YYYY/MM/DD hour:minutes:seconds
   Resolution:	1

   Excess Radon (dpm m-3)

   Excess Radon (Source: Producer Defined)

   Range of values
   Minimum:	342
   Maximum:	6911
   Units:	centimeters per day
   Resolution:	1

   Water Level (m)

   Water Level (Source: Producer Defined)

   Range of values
   Minimum:	0.81
   Maximum:	2.43
   Units:	meters
   Resolution:	0.01

   Latitude (Decimal Degrees)

   Latitude in decimal degrees (Source: Global Positioning System)

   Range of values
   Minimum:	-14.28986
   Maximum:	-14.28889
   Units:	decimal degrees
   Resolution:	0.00001

   Longitude (Decimal Degrees)

   Longitude in decimal degrees (Source: Global Positioning System)

   Range of values
   Minimum:	-170.68070
   Maximum:	-170.68171
   Units:	decimal degrees
   Resolution:	0.00001

   Entity_and_Attribute_Overview: The first line of the csv file is a header line.
   Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Ferdinand K.J. Oberle
   • Nancy G. Prouty
   • Curt D. Storlazzi
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

Radon (Rn-222) data were collected to characterize the advection rate of groundwater onto the near-shore reef. When analyzed in conjunction with measurements of changing water levels from tides and waves, the data can be used to assess the potential for terrestrial groundwater intrusion on the reef and the sources and fate of these water masses.

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: 11-Aug-2018 (process 1 of 1)

   Radon (Rn-222) concentration data were collected with a DURRIDGE RAD7 radon detector. The alpha decay of Rn-222 was detected at 3-minute intervals with the RAD7 in SNIFF mode. In SNIFF mode, the instrument detects radon entry points and gushers, and it recovers from high radon exposures in minutes. At the end of each run, the detector printed out a complete report. The RAD7 data were QA/QC’d, and raw counts of radon were exported using the manufacturer’s CAPTURE software.

3. What similar or related data should the user be aware of?
   Burnett, W.C., Kim, G., and Lane-Smith, D., 2001, A continuous monitor for assessment of 222Rn in the coastal ocean.

   Online Links:

   • https://doi.org/10.1023/A:1013217821419

   Other_Citation_Details:

   Burnett, W.C., Kim, G., and Lane-Smith, D., 2001, A continuous monitor for assessment of 222Rn in the coastal ocean: Journal of Radioanalytical and Nuclear Chemistry, v. 249, p. 167–172

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

1. How well have the observations been checked?
   No formal attribute accuracy tests were conducted.
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. The stated accuracy of the GPS unit used to determine the location of the instruments is +/- 5 m.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Data fall within expected ranges.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:

USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in comma-delimited ascii csv format contained in a single file (Faga18_Rn_data.csv) accompanied by CMGDS FGDC-compliant metadata.
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:	CSV ascii text file contains the data. in format comma-delimited text Size: 0.003
     Network links:	https://www.sciencebase.gov/catalog/file/get/6074f9a3d34e018b31fff905 https://doi.org/10.5066/P9F0LJNC

   • 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 text editor software.

Who wrote the metadata?

Dates:

Last modified: 20-May-2021

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-460-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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