Nearshore seawater-column measurements of coastal groundwater discharge, Ofu, American Samoa, February 2020

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Ferdinand K. Oberle
Originator: Nancy G. Prouty
Originator: Curt Storlazzi
Publication_Date: 20250508
Title:
Nearshore seawater-column measurements of coastal groundwater discharge, Ofu, American Samoa, February 2020
Geospatial_Data_Presentation_Form: comma-delimited text
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P13RJCAJ
Publication_Information:
Publication_Place:
Pacific Coastal and Marine Science Center, Santa Cruz, California
Publisher: U.S. Geological Survey
Other_Citation_Details:
Suggested Citation: Oberle, F.K., Prouty, N.G., and Storlazzi, C.D. 2025, Nearshore seawater-column measurements of coastal groundwater discharge, Ofu, American Samoa, February 2020: U.S. Geological Survey data release, https://doi.org/10.5066/P13RJCAJ.
Online_Linkage: https://doi.org/10.5066/P13RJCAJ
Online_Linkage:
https://www.sciencebase.gov/catalog/item/67e2f32cd34ee7f142216d0c
Description:
Abstract:
In-situ nearshore seawater measurements of dissolved radon and water level were used to determine the advection rate of groundwater onto the fringing reef off Ofu, American Samoa.
Purpose:
Radon (Rn-222) data were collected to characterize the advection rate of groundwater onto the nearshore reef. When analyzed in conjunction with measurements of changing water levels from tides the data can be used to assess the potential for terrestrial groundwater intrusion and the sources and fate of these water masses.
Supplemental_Information:
Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2020-620-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20200201
Ending_Date: 20200207
Currentness_Reference: ground condition at time data were collected
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -169.666217
East_Bounding_Coordinate: -169.658219
North_Bounding_Coordinate: -14.181312
South_Bounding_Coordinate: -14.185000
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: geoscientificInformation
Theme:
Theme_Keyword_Thesaurus: Data Categories for Marine Planning
Theme_Keyword: Water Column Features
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: time series datasets
Theme_Keyword: marine water quality
Theme:
Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
Theme_Keyword: physical oceanography
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Hazards and Resources Program
Theme_Keyword: CMHRP
Theme_Keyword: Pacific Coastal and Marine Science Center
Theme_Keyword: PCMSC
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:67e2f32cd34ee7f142216d0c
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Ofu
Place_Keyword: Territory of American Samoa
Place_Keyword: Papaloloa Point
Place_Keyword: Fatuana Point
Place_Keyword: South Pacific Ocean
Access_Constraints:
No restrictions or legal prerequisites for accessing the dataset.
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.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Contact_Person: PCMSC Science Data Coordinator
Contact_Address:
Address_Type: mailing and physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060
Contact_Voice_Telephone: 831-460-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov
Native_Data_Set_Environment:
Raw data from the DURRIDGE RAD7 radon detector were processed using the manufacturers software, DURRIDGE CAPTURE, on a Dell Personal Computer running Windows 7 Operating System.
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
No formal attribute accuracy tests were conducted. DURRIDGE RAD7 radon detectors were calibrated using Durridge services to achieve a reproducibility of better than ±2% and an overall calibration accuracy of better than ±5%. Calibrations are carried out with a National Institute of Standards and Technology radon standard supplied through the U.S. EPA.
Logical_Consistency_Report: Data fall within expected ranges.
Completeness_Report:
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.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
A formal accuracy assessment of the vertical information in the data set has not been conducted. The stated accuracy of the Hastelloy pressure sensor used to determine the depth of the instrument is +/- 1 cm.
Lineage:
Process_Step:
Process_Description:
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. Conductivity and water level (CTD) data were collected with a YSI Castaway CTD Profiler.
Process_Date: 20160803
Spatial_Data_Organization_Information:
Indirect_Spatial_Reference:
Data were collected continuously at a single point at Papaloloa Point and Fatuana Point, Ofu, American Samoa.
Direct_Spatial_Reference_Method: Point
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 776
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000001
Longitude_Resolution: 0.000001
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS_1984
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257223563
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label:
Ofu20_Rn_data_200off_1.csv, Ofu20_Rn_data_200on_2.csv, Ofu20_Rn_data_300off_6.csv, Ofu20_Rn_data_300on_5.csv, Ofu20_Rn_data_200east_off_4.csv, and Ofu20_Rn_data_200east_on_3.csv
Entity_Type_Definition: Comma Separated Value (CSV) file containing data.
Entity_Type_Definition_Source: Producer Defined
Attribute:
Attribute_Label: Date
Attribute_Definition: Date and time referenced to Universal Coordinate Time
Attribute_Definition_Source: Global Positioning System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2/1/2020 16:08
Range_Domain_Maximum: 2/7/2020 9:49
Attribute_Units_of_Measure: MM/DD/YY hour:minutes
Attribute_Measurement_Resolution: 1
Attribute:
Attribute_Label: Excess_Radon_(dpm/m3)
Attribute_Definition: Excess Radon
Attribute_Definition_Source: Producer Defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -8.7000
Range_Domain_Maximum: 147987.9773
Attribute_Units_of_Measure: Disintegrations per minute (dpm) per cubic meter (m3)
Attribute_Measurement_Resolution: 0.0001
Attribute:
Attribute_Label: Water_Level_(m)
Attribute_Definition: Water Level
Attribute_Definition_Source: Producer Defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.031073130
Range_Domain_Maximum: 1.084792501
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.000000001
Attribute:
Attribute_Label: Latitude_(Decimal_Degrees)
Attribute_Definition: Latitude in decimal degrees
Attribute_Definition_Source: Global Positioning System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -14.185000
Range_Domain_Maximum: -14.181312
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.000001
Attribute:
Attribute_Label: Longitude_(Decimal_Degrees)
Attribute_Definition: Longitude in decimal degrees
Attribute_Definition_Source: Global Positioning System
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -169.666217
Range_Domain_Maximum: -169.658219
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.000001
Overview_Description:
Entity_and_Attribute_Overview: The first line of the csv file is a header line.
Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey - ScienceBase
Contact_Address:
Address_Type: mailing and physical
Address: Denver Federal Center, Building 810, Mail Stop 302
City: Denver
State_or_Province: CO
Postal_Code: 80225
Contact_Voice_Telephone: 1-888-275-8747
Contact_Electronic_Mail_Address: sciencebase@usgs.gov
Resource_Description:
These data are available in comma-delimited (csv) format contained in a single zipped folder (Ofu20_Rn_Data.zip) accompanied by CMGDS FGDC-compliant metadata.
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: comma-delimited text
Format_Version_Date: 20180818
Format_Information_Content: CSV text file contains the data.
File_Decompression_Technique: WinZip or archive utility
Transfer_Size: 0.013
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
https://www.sciencebase.gov/catalog/file/get/67e2f32cd34ee7f142216d0c
Network_Resource_Name: https://doi.org/10.5066/P13RJCAJ
Access_Instructions:
Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of data and metadata. The second link points to a landing page with metadata and data for the entire data release.
Fees: None.
Technical_Prerequisites: These data can be viewed with any text editor software.
Metadata_Reference_Information:
Metadata_Date: 20250508
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Contact_Person: PCMSC Science Data Coordinator
Contact_Address:
Address_Type: mailing and physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060
Contact_Voice_Telephone: 831-460-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov
Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_P13RJCAJ/Ofu20_Rn_metadata.html>
Generated by mp version 2.9.51 on Fri May 9 14:39:01 2025