Minimal offshore extent of ice-bearing (subsea) permafrost on the U.S. Beaufort Sea margin

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Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Brothers, Laura L.
Originator: Ruppel, Carolyn D.
Originator: Hart, Patrick E.
Originator: Herman, Bruce M.
Publication_Date: 2019
Title:

Minimal offshore extent of ice-bearing (subsea) permafrost on the U.S. Beaufort Sea margin

Edition: 1.0
Geospatial_Data_Presentation_Form: vector digital data
Series_Information:

Series_Name: data release
Issue_Identification: DOI:10.5066/P96FB9F7

Publication_Information:

Publication_Place:

Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts

Publisher:

U.S. Geological Survey, Coastal/Marine Hazards and Resources Program

Other_Citation_Details:

Suggested citation: Brothers, L.L., Ruppel, C.D., Hart, P.E., and Herman, B.M., 2019, Minimal offshore extent of ice-bearing (subsea) permafrost on the U.S. Beaufort Sea margin: U.S. Geological Survey data release, https://doi.org/10.5066/P96FB9F7.

Online_Linkage: https://doi.org/10.5066/P96FB9F7
Online_Linkage:

https://www.sciencebase.gov/catalog/item/5c90f6d0e4b0938824547e4d

Description:

Abstract:

The present-day distribution of subsea permafrost beneath high-latitude continental shelves has implications for sea level rise and climate change since the Last Glacial Maximum (~20,000 years ago). Because permafrost can be spatially associated with gas hydrate (which may be thermodynamically stable within the several hundred meters above and below the base of permafrost), the contemporary distribution of subsea permafrost also has implications for the persistence of permafrost-associated gas hydrate beneath shallow waters at high latitudes, particularly on margins that were not glaciated at the Last Glacial Maximum. On the U.S. Beaufort Sea margin offshore northern Alaska, researchers have sometimes assumed that contemporary subsea permafrost extends to the 100 meter isobath on the outer continental shelf. Using a compilation of more than 50,000 stacking velocities from ~100,000 line-km of industry-collected multichannel seismic reflection data acquired over 57,000 square kilometers of the U.S. Beaufort Sea continental shelf, we derive the average (bulk) velocity in the upper 750 milliseconds of two-way travel time (TWTT). An average velocity of 2000 meters per second (m/s) is used to delineate the offshore extent of ice-bearing permafrost that has not thawed since the end of the Last Glacial Maximum. The 2000 m/s velocity contour represented in this data release is within 37 km of the modern U.S. Beaufort shoreline and at water depths less than 25 m. The contour was determined as part of a study by Brothers, L. L., B. M. Herman, P. E. Hart, and C. D. Ruppel (2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data, Geochemistry, Geophysics, Geosystems, 17, 4354–4365, doi:10.1002/2016GC006584. Direct borehole observations of ice-bearing permafrost in the same area as the 2000 m/s velocity contour from this data set are described in the associated work: Ruppel, C. D., B. M. Herman, L. L. Brothers, and P. E. Hart (2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints, Geochemistry, Geophysics, Geosystems, 17, 4333–4353, doi:10.1002/2016GC006582. The placement of the 2000 m/s contour derived from seismic reflection stacking velocities is similar to, but not exactly the same as, the extent of subsea permafrost inferred based on earlier seismic refraction analyses of Brothers, L. L., P. E. Hart, and C. D. Ruppel (2012), Minimum distribution of subsea ice-bearing permafrost on the U.S. Beaufort Sea continental shelf, Geophys. Res. Lett., 39, L15501, doi:10.1029/2012GL052222.

Purpose:

This shapefile was formulated for the purpose of delineating the 2000 meter per second (m/s) contour for average sediment velocities calculated for the first 750 milliseconds of two-way travel time from legacy seismic reflection records collected near the Alaskan coastline bordering the U.S. Beaufort Sea. The 2000 m/s averaged sediment velocity contour is interpreted as the contemporary seaward extent of ice-bearing permafrost (subsea permafrost) on the U.S. Beaufort Sea margin (Arctic Ocean) offshore northern Alaska.

Supplemental_Information:

The date range given for "time period information" is approximate and is meant to encompass the range of dates over which the original seismic data were acquired. In the first cross-referenced work, the original seismic data were described as being collected in the mid-1970s in the Beaufort Sea and onshore in the National Petroleum Research Reserve and the Arctic National Wildlife Refuge from 1977 to 1990. However, the permit numbers associated with the data indicate that the data were acquired only between 1977 and 1990. A subset of the data used in this study (e.g., scanned tiff images of the semblance based velocity analyses, the compiled results of the velocities picked from the semblance based analyses, processed seismic data, and navigation files) is available from the National Archive of Marine Seismic Surveys (NAMSS) https://walrus.wr.usgs.gov/NAMSS/. All of the other velocity data used in this study are available from the Bureau of Ocean Energy Management (BOEM) Alaska Region. Interested parties may submit Freedom of Information Act requests to BOEM with the permit number in order to obtain this information. The permit numbers (NAMSS ID is in parentheses where applicable) are: 77-25 (B-25-77-AK), 80-01, 80-03 (B-03-80-AR), 80-42, 81-02 (B-02-81-AR), 81-23 (B-23-81-AR), 82-59 (B-59-82-AR), 83-28, 84-37, 85-49, 87-04, 87-15 (B-15-87-AR), 90-05, and 90-15. The original list of permit numbers is provided in the Supporting Information published with Brothers, L. L., B. M. Herman, P. E. Hart, and C. D. Ruppel (2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data, Geochemistry, Geophysics, Geosystems, 17, 4354–4365, doi:10.1002/2016GC006584. The Supporting Information can be accessed at http://agupubs.onlinelibrary.wiley.com/doi/10.1002/2016GC006584.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19770101
Ending_Date: 19901231

Currentness_Reference: source data

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -157.0262
East_Bounding_Coordinate: -140.5589
North_Bounding_Coordinate: 71.9791
South_Bounding_Coordinate: 69.4095

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:5c90f6d0e4b0938824547e4d

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Woods Hole Coastal and Marine Science Center
Theme_Keyword: PCMSC
Theme_Keyword: WHCMSC
Theme_Keyword: Coastal/Marine Hazards and Resources Program
Theme_Keyword: CMHRP
Theme_Keyword: Department of the Interior
Theme_Keyword: shapefile
Theme_Keyword: seismic interpretation
Theme_Keyword: seismic navigation
Theme_Keyword: seismic reflection
Theme_Keyword: seismic profile

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: oceans
Theme_Keyword: geoscientificInformation

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: permafrost
Theme_Keyword: marine geophysics
Theme_Keyword: marine geology
Theme_Keyword: seismic reflection methods

Theme:

Theme_Keyword_Thesaurus: Coastal and Marine Ecological Classification Standard
Theme_Keyword: Beaufort Sea Continental Coast and Shelf

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Arctic
Place_Keyword: Alaska
Place_Keyword: Beaufort Sea
Place_Keyword: Harrison Bay
Place_Keyword: Camden Bay
Place_Keyword: Barrow Canyon

Temporal:

Temporal_Keyword_Thesaurus: None
Temporal_Keyword: 1977
Temporal_Keyword: 1980
Temporal_Keyword: 1981
Temporal_Keyword: 1982
Temporal_Keyword: 1983
Temporal_Keyword: 1984
Temporal_Keyword: 1985
Temporal_Keyword: 1987
Temporal_Keyword: 1990

Access_Constraints: None. Please see 'Distribution Info' for details.
Use_Constraints:

None. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Browse_Graphic:

Browse_Graphic_File_Name:

https://www.sciencebase.gov/catalog/file/get/5c90f6d0e4b0938824547e4d?name=AlaskasubseaIBPF_USGS.png

Browse_Graphic_File_Description:

Image of shapefile indicating location of 2000 m/s velocity contour, which is taken as a proxy for the minimal offshore extent of ice-bearing permafrost (subsea permafrost) on the U.S. Beaufort Sea margin.

Browse_Graphic_File_Type: PNG

Data_Set_Credit:

The seismic data for this study and most of the stacking velocities were provided to the U.S. Bureau of Ocean Energy Management by companies that collected the original data. The data are now more than 25 years old and are in the public domain. The Bureau of Ocean Energy Management, DOE-USGS Interagency Agreement DE-FE0002911, and the USGS Gas Hydrates Project supported this research. Laura Brothers was also supported by a DOE National Energy Technology Laboratory/National Research Council Methane Hydrate Fellowship under DE-FC26-05NT42248 to conduct this research from 2010 to 2012.

Native_Data_Set_Environment:

The shapefile was generated in the Microsoft Windows 7 Enterprise edition emulation environment using ArcGIS version 9. Filename: AlaskasubseaIBPF_USGS.zip. The Zip archive contains the ArcGIS shapefile (*.shp), which is associated with other filenames with the same prefix and suffixes of: *.dbf, *.prj, *.sbn, *sbx, and *.shx. Thus, the zip archive contains 6 files associated with the Esri shapefile, the PNG browse image, and the metadata in XML, TXT, and other formats.

Cross_Reference:

Citation_Information:

Originator: Laura L. Brothers
Originator: Bruce M. Herman
Originator: Patrick E. Hart
Originator: Carolyn D. Ruppel
Publication_Date: 20161011
Title:

Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data

Geospatial_Data_Presentation_Form: publication
Series_Information:

Series_Name: Geochemistry, Geophysics, Geosystems
Issue_Identification: vol. 17, issue 11, pp. 4354-4365

Publication_Information:

Publication_Place: n/a
Publisher: American Geophysical Union (AGU)

Other_Citation_Details:

Suggested citation: Brothers, L. L., Herman, B. M., Hart, P. E., and Ruppel, C. D. ( 2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data, Geochem. Geophys. Geosyst., 17, pp. 4354– 4365, doi:10.1002/2016GC006584.

Online_Linkage: http://agupubs.onlinelibrary.wiley.com/doi/10.1002/2016GC006584

Cross_Reference:

Citation_Information:

Originator: Carolyn D. Ruppel
Originator: Bruce M. Herman
Originator: Laura L. Brothers
Originator: Patrick E. Hart
Publication_Date: 20161104
Title:

Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints

Geospatial_Data_Presentation_Form: publication
Series_Information:

Series_Name: Geochemistry, Geophysics, Geosystems
Issue_Identification: vol. 17, issue 11, pp. 4333-4353.

Publication_Information:

Publication_Place: n/a
Publisher: American Geophysical Union (AGU)

Other_Citation_Details:

Ruppel, C. D., Herman, B. M., Brothers, L. L., and Hart, P. E. ( 2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints, Geochem. Geophys. Geosyst., 17, pp. 4333–4353, doi:10.1002/2016GC006582.

Online_Linkage:

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GC006582

Cross_Reference:

Citation_Information:

Originator: Laura L. Brothers
Originator: Patrick E. Hart
Originator: Carolyn D. Ruppel
Publication_Date: 20120807
Title:

Minimum distribution of subsea ice-bearing permafrost on the U.S. Beaufort Sea continental shelf

Geospatial_Data_Presentation_Form: publication
Series_Information:

Series_Name: Geophysical Research Letters
Issue_Identification: vol. 39, issue 15, L15501

Publication_Information:

Publication_Place: n/a
Publisher: American Geophysical Union (AGU)

Other_Citation_Details:

Brothers, L. L., Hart, P. E., and Ruppel, C. D. ( 2012), Minimum distribution of subsea ice-bearing permafrost on the U.S. Beaufort Sea continental shelf, Geophys. Res. Lett., 39, L15501, doi:10.1029/2012GL052222.

Online_Linkage:

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012GL052222

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Because this dataset is not "observational," but rather "calculated," the accuracy is only as good as (a) the underlying stacking velocities, which were spot checked in the original studies and from which anomalous values were discarded; (b) the methods used to convert stacking velocities to average (bulk) velocities (Vsed) in the upper 750 ms of two-way travel time, which rely primarily on the widely-used Dix equation; (c) the Dix calculation used to infer the bulk velocity of the uppermost section of offshore sediments (Vave) after the water is stripped off (Equation 1 of the first cross-referenced work); and (d) contouring routines within ArcGIS software. Most of the inaccuracy in the location of 2000 m/s velocity contour as captured in this data release likely arises due to (b) in the list above, with (c) also contributing.
To assess the potential inaccuracy related to (b): Based on a sensitivity analysis for determination of Vave from Equation (1) in the first cross-referenced paper (Brothers, L. L., B. M. Herman, P. E. Hart, and C. D. Ruppel (2016), Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data, Geochemistry, Geophysics, Geosystems, 17, 4354–4365, doi:10.1002/2016GC006584; see also process step 4 of this metadata file), a 5% inaccuracy in the determination of Vsed for an assumed water column two-way travel time TWC of 10 ms (~15 m water depth) and the 1475 m/s Vwc (water column velocity) adopted in the first cross-referenced paper will produce slightly more than a 5% deviation in Vave. Thus, a 100 m/s inaccuracy in Vsed could propagate as more than a 100 m/s inaccuracy in Vave. However, this inaccuracy would be on a point by point basis for the 50,000 stacking velocity points used in this analysis. The inaccuracy would have to be systematic amongst these 50,000 points for the contours of Vave in Figure 3 of the first cross-referenced paper to shift appreciably and for the position of the 2000 m/s contour that constitutes this shapefile to be affected.
To assess the potential inaccuracy related to (c): Vave for a given bulk sediment velocity Vsed between the observed values of 1475 to 3110 m/s will vary by less then 1.3% for water column velocity (Vwc) between 1400 and 1500 m/s and for a deeper water (~75 m) part of the shelf (two-way travel time TWC for the water column = 100 ms). The largest variation is for these larger water depths and for the lowest assumed Vwc. A variation of 1% at 75 m water depth (outer shelf) is only ~19 m/s. Figure 3 of the first cross-referenced paper depicts a steep offshore gradient in Vsed, which is contoured at 100 m/s. The calculated maximum inaccuracy is therefoer only ~one-fifth of 100 m/s. Thus, uncertainties due to Vwc differing from the assumed value of 1475 m/s would not be significant.

Logical_Consistency_Report:

Each Vave used as the basis for contouring the entire dataset of Vave values to produce the shapefile was determined using the same process. As described in the first cross-referenced work, stacking velocities that were clearly anomalous were analyzed prior to their use in determining Vsed and thence Vave (see Process Steps) and discarded if the values were not physically reasonable. As a general example (not one specific to this dataset), if a stacking velocity were significantly lower than the speed of sound in water, this stacking velocity would be considered anomalous.

Completeness_Report:

The shapefile was derived by contouring all Vave values determined from the original stacking velocities deemed to be within physically reasonable limits. No values of Vave were selectively discarded prior to contouring, nor were values changed.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Spatial inaccuracy could result from attribution of stacking velocities to the wrong location by the companies that provided those data to the U.S. Bureau of Ocean Energy Management and/or from poor navigation of the original seismic data. No further information on spatial inaccuracy is available, and navigation for the original data is unknown. The horizontal positional information provided for the stacking velocities used for this study do correspond to locations along known seismic lines, which is a first-order indication that the positions are reasonable.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: various companies
Publication_Date: 19901231
Title:

Seismic imagery and stacking velocities for private-sector seismic surveys onshore and offshore along the U.S. Beaufort Sea coastline

Geospatial_Data_Presentation_Form: remote-sensing image

Type_of_Source_Media: Digital and/or Hardcopy
Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19770101
Ending_Date: 19901231

Source_Currentness_Reference:

In some cases, stacking velocity analysis was updated at time of production of the first cross-referenced work.

Source_Citation_Abbreviation:

Industry seismic data provided to the Bureau of Ocean Energy Management -- Alaska Region

Source_Contribution:

various companies; see Supplemental Information in this metadata file for permit numbers corresponding to seismic data used for the first cross-referenced work, information about how to obtain the data, and alternate ways to access a subset of the data

Process_Step:

Process_Description:

STEP 1: The stacking velocity was converted to an average bulk compressional velocity (Vave) using the Dix equation at the discrete picked times for each stacking velocity analysis. (processing date is approximate)

Process_Date: 20140416
Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Process_Step:

Process_Description:

STEP 2: A cubic spline was fitted to Vave at each velocity analysis location, from which Vave was interpolated to 750 milliseconds (ms) two-way travel time (TWTT). Note that 750 ms TWTT nominally corresponds to the uppermost ~600 meters (m) of section offshore and possibly up to ~1000 m for locations with permafrost. (processing date is approximate)

Process_Date: 20140416
Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Process_Step:

Process_Description:

STEP 3: In order to grid the Vave values at points evenly spaced in distance and then contour these values, the Vave value at each latitude and longitude (geographic coordinate system) from the previous step had to be ascribed to an x-y location in a planar coordinate system. Using ArcGIS, the original geodetic datum (NAD27) provided by the Bureau of Ocean Energy Management was retained, and the Vave value locations were converted to x-y locations in Universal Transverse Mercator zone 6N. UTM zone 6N is a Northern Hemisphere UTM zone bounded by 144 degrees West Longitude and 150 degrees West longitude and 0 degrees north latitude and 84 degrees north latitude. Note that, according to metadata in NAMSS (see Data Credit) for the original data acquisitions, the seismic surveys were mostly referenced to the NAD83 datum, even though some of the surveys preceded development of the NAD83 standard. It is not known if this description of the original data is correct. (processing date is approximate)

Process_Date: 20140416
Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Process_Step:

Process_Description:

STEP 4: Vave were gridded with 2 km node spacing in GeoFrame software, where they were smoothed with a two-pass biharmonic ﬁlter. (processing date is approximate; this step completed by Bruce Herman (retired) of the Bureau of Ocean Energy Management in Anchorage, Alaska)

Process_Date: 20140416

Process_Step:

Process_Description:

STEP 5: The variation in water depth across the shelf introduces a slight gradient in Vave (average velocity from 0 to 750 ms TWTT). Using the Dix Equation, the velocity of the sediment alone (Vsed) was therefore calculated using: (Vsed)^2 = [(Vave^2 x 750 ms) - (Vwc^2 x Twc)] / (750 ms - Twc), where Vwc is water column velocity (assumed 1475 m/s), and Twc is TWTT for the water column. This step was completed using Excel spreadsheets. (processing date is approximate)

Process_Date: 20140416
Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Process_Step:

Process_Description:

STEP 6: The resulting Vsed values were contoured in Esri ArcGIS and the 2000 m/s contour extracted to make the shapefile for this dataset.(processing date is approximate)

Process_Date: 20140416
Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Laura Brothers
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geologist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US

Contact_Voice_Telephone: 508-458-8700 x2312
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: lbrothers@usgs.gov

Process_Step:

Process_Description:

Added keywords section with USGS persistent identifier as theme keyword.

Process_Date: 20200806
Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross

Contact_Position: Marine Geologist
Contact_Address:

Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598

Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: String
Point_and_Vector_Object_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:

UTM_Zone_Number: 6
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -147.0
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000.0
False_Northing: 0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:

Abscissa_Resolution: 0.6096
Ordinate_Resolution: 0.6096

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North_American_Datum_1927
Ellipsoid_Name: Clarke_1866
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.9786982

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: AlaskasubseaIBPF_USGS.shp
Entity_Type_Definition: polyline shapefile of minimal offshore permafrost extent
Entity_Type_Definition_Source: U.S. Geological Survey

Attribute:

Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated. Because this is a polyline, the only FID is "0".

Attribute:

Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the feature. This feature is a polyline.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey - ScienceBase

Contact_Address:

Address_Type: mailing address
Address: Denver Federal Center, Building 810, Mail Stop 302
City: Denver
State_or_Province: CO
Postal_Code: 80225
Country: United States

Contact_Voice_Telephone: 1-888-275-8747
Contact_Electronic_Mail_Address: sciencebase@usgs.gov

Resource_Description:

AlaskasubseaIBPF_USGS.zip: File contains the polyline feature class (AlaskasubseaIBPF_USGS.shp), the browse graphic (AlaskasubseaIBPF_USGS.png), and associated FGDC CSDGM metadata in XML,HTML, FAQ, and text formats.

Distribution_Liability:

Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: Shapefile
Format_Version_Number: ArcGIS 9
Format_Specification: Esri polyline Shapefile
Format_Information_Content:

The Zip file contains the polyline shapefile for the minimal offshore extent of ice-bearing (subsea) permafrost on the U.S. Beaufort Sea margin, along with the FGDC CSDGM metadata in various formats and the browse graphic.

File_Decompression_Technique: 7Zip
Transfer_Size: 3

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

https://www.sciencebase.gov/catalog/file/get/5c90f6d0e4b0938824547e4d?name=AlaskasubseaIBPF_USGS.zip

Network_Resource_Name: https://doi.org/10.5066/P96FB9F7

Access_Instructions:

The first link downloads the shapefile, associated Esri files, and the metadata as a single Zip file. The second link is the ScienceBase landing page.

Fees: None

Technical_Prerequisites:

These data are available in Esri shapefile format. The user must have software capable of reading this format. The data are available for download in zip format, which requires software to extract the files from the zip archive.

Metadata_Reference_Information:

Metadata_Date: 20240319
Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Carolyn Ruppel
Contact_Organization: U.S. Geological Survey, Northeast Region

Contact_Position: Research Geophysicist
Contact_Address:

Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: United States

Contact_Voice_Telephone: 508-458-8700 x2339
Contact_Electronic_Mail_Address: 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. (updated on 20240319)

Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P96FB9F7/AlaskasubseaIBPF_USGS.html>