How, Amelia R.
Ruppel, Carolyn D.
20230202
Global compilation of published gas hydrate-related bottom simulating reflections
1.0
vector digital data
data release
DOI:10.5066/P9IW5CL7
Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts
U.S. Geological Survey, Coastal and Marine Hazards and Resources Program
Suggested citation: How, A.R., and Ruppel, C.D., 2023, Global compilation of published gas hydrate-related bottom simulating reflections: U.S. Geological Survey data release, https://doi.org/10.5066/P9IW5CL7.
https://doi.org/10.5066/P9IW5CL7
https://www.sciencebase.gov/catalog/item/63caaf8cd34e06fef14f3e2a
Bottom simulating reflections (BSRs) are seismic features that are imaged in marine sediments using high-energy, impulsive seismic sources such as air guns or generator-injector guns. BSRs often cut across sediment stratigraphy and are interpreted as marking the deepest depth at which gas hydrate can exist. Gas hydrate is a naturally occurring and widely distributed frozen form of water and gas (usually methane) stable at low temperatures (up to about 25 degrees Celsius [°C]) and intermediate pressures (those that usually correspond to greater than 500 meters water depth). BSRs have been mapped in all the world’s oceans, in inland seas (such as the Black Sea), and in Lake Baikal in Russia.
This data release consists of a GeoPackage that compiles digitized BSR maps from published scientific papers and other sources into a single resource, with attribution to the original researchers. An associated spreadsheet provides the same descriptive information about each of the original BSR maps in a form accessible without opening the GeoPackage. A GeoPackage is an open-source, platform-independent, standards-based package of geospatial data for a geographic information system (GIS).
To formulate the dataset, published BSR maps were georeferenced, digitized, and converted to a common geographic coordinate system, and the resulting files were assigned a quality factor based on characteristics of the original maps and the difficulty of georeferencing. As described in detail in the associated metadata, most maps had a single polygon or multiple polygons enclosing the area where BSRs were recognized by the original researchers. Some maps had only circles or ovals around areas interpreted as containing BSRs, and these geometric shapes were digitized for the database. A few maps indicated the precise segments of individual seismic lines where BSRs are identified, resulting in BSRs being digitized as polylines instead of polygons. Polygons for BSRs in the northern Gulf of Mexico and U.S. Atlantic margin are based on files provided for direct release (no georeferencing necessary) by the Bureau of Ocean Energy Management.
This GeoPackage was formulated for the purpose of compiling polygons and polylines showing the locations of bottom simulating reflections (BSRs) likely associated with the presence of gas hydrates in marine sediments on global continental margins. The BSRs are primarily from published maps, with additional BSRs from online maps or digital files provided directly to the U.S. Geological Survey by the Bureau of Ocean Energy Management.
The compilation is not exhaustive of all bottom simulating reflections (BSRs) in the English-language scientific literature since some published maps lack sufficient features (e.g., coastlines) or geographic coordinates to allow them to be georeferenced for digitization of the BSRs. Especially at high latitudes, some published maps could not be included in the compilation since the original map was published in an unknown projection that caused the maps to be highly distorted once georeferenced. In some cases, the maps chosen for this compilation represent an updated, more complete, or more precise rendering of BSRs than available in alternate publications. The authors of this dataset may also have missed published references that contained digitizable BSRs from areas not currently represented in the database, and the contact for the dataset (Carolyn Ruppel, cruppel@usgs.gov) can be reached to provide such information for consideration for inclusion in an update planned for 2025. The date range given for "time period information" encompasses the range of dates over which the maps were published, not the dates over which the supporting seismic information for each published map was acquired or interpreted.
19880101
20221231
The date range given for "time period information" encompasses the range of dates over which the maps were published, not the dates over which the supporting seismic information for each published map was acquired or interpreted.
Update planned in 2025
-158.577649
179.056773
81.538744
-61.512652
None
U.S. Geological Survey
USGS
Woods Hole Coastal and Marine Science Center
WHCMSC
Coastal and Marine Hazards and Resources Program
CMHRP
Department of the Interior
GeoPackage
seismic reflection
ISO 19115 Topic Category
oceans
geoscientificInformation
environment
USGS Thesaurus
sea-floor characteristics
gas hydrate resources
natural gas resources
marine geophysics
seismic reflection methods
Coastal and Marine Ecological Classification Standard
Beaufort Sea Continental Coast and Shelf
Temperate Northern Atlantic
Northern Gulf of Mexico
Temperate Northern Pacific
Arctic
marine offshore
seep
USGS Metadata Identifier
USGS:63caaf8cd34e06fef14f3e2a
None
Falkland Islands (Islas Malvinas)
South Africa
Black Sea
Mid Atlantic
Atlantic
United States
Gulf of Mexico
Cascadia
Taiwan
Nigeria
Congo
Sea of Okhotsk
Russia
New Zealand
Brazil
Colombia
Ecuador
Chile
Patagonia
Barents Sea
Uruguay
Argentina
Amazonia
Antarctica
Sumatra
Pacific
India
China
South China Sea
Japan
Sea of Japan
Republic of Korea
Indonesia
Canada
Greenland
Svalbard
Norwegian-Greenland Sea
Barents Sea
Alaska
Beaufort Sea
None
1988
1990
1997
1998
2000
2002
2003
2004
2006
2008
2009
2010
2011
2012
2013
2014
2018
2020
2022
None. Please see 'Distribution Info' for details.
Not for use for navigation or scientific/resource planning. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations and to consult the original references for further information about the maps included in this compilation.
Carolyn Ruppel
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2339
508-457-2310
cruppel@usgs.gov
https://www.sciencebase.gov/catalog/file/get/63caaf8cd34e06fef14f3e2a?name=BSRbrowsegraphic.png
Image of global BSRs (red) included this release
PNG
The bottom simulating reflections digitized for this release are published in the figure numbers (where applicable) in the references provided in the "reference" column of the GeoPackage attribute table and the Excel spreadsheet. DOE-USGS Interagency Agreement 89243320SFE000013 and the USGS Gas Hydrates Project (Energy Resources Program and Coastal and Marine Hazards and Resources Program) supported this research.
The GeoPackage (filename USGS_DigitizedBSRs_GeoPackage.gpkg) was generated using QGIS 3.16.7-Hannover running on a Windows 10 machine, and the spreadsheet (USGS_DigitizedBSRs_table.xlsx) was generated using Microsoft Office Excel 365 on a Windows 10 computer. The release also contains the PNG browse image (BSRbrowsegraphic.png), and the metadata in XML, TXT, and other formats.
Carolyn D. Ruppel
William F. Waite
20200604
Timescales and processes of methane hydrate formation and breakdown, with application to geologic systems
Journal of Geophysical Research
vol. 125, e2018JB016459
n/a
American Geophysical Union (AGU)
Ruppel, C.D., and Waite, W.F., 2020, Grand challenge: Timescales and processes of methane hydrate formation and breakdown, with application to geologic systems: Journal of Geophysical Research Solid Earth, 125, https://doi.org/10.1029/2018JB016459
https://doi.org/10.1029/2018JB016459
William F. Waite
Carolyn D. Ruppel
Lee-Gray Boze
Thomas D. Lorenson
Brian J. Buczkowski
Katherine Y. McMullen
Keith A. Kvenvolden
20200611
Preliminary global database of known and inferred gas hydrate locations
1.0
XLXS spreadsheet
data release
DOI:10.5066/P9LLFVJM
Woods Hole Coastal and Marine Science Center, Woods Hole, MA
U.S. Geological Survey, Coastal and Marine Hazards and Resources Program
Suggested citation: Waite, W.F., Ruppel, C.D., Boze, L-G., Lorenson, T.D., Buczkowski, B.J., McMullen, K.Y., and Kvenvolden, K.A., 2020, Preliminary global database of known and inferred gas hydrate locations: U.S. Geological Survey data release, https://doi.org/10.5066/P9llFVJM.
https://doi.org/10.5066/P9LLFVJM
https://www.sciencebase.gov/catalog/item/5eb413a282ce25b5135a9f2a
The geographic accuracy of the digital bottom simulating reflection (BSR) locations in this dataset depends on (a) the accuracy of the BSR delineations in the original references; (b) the quality of the georeferencing and digitization that could be achieved for the files (all except BOEM2012 and Shedd2012) that required these processing steps; (c) decisions made about how to digitize the BSRs for this dataset. In addition, the dataset as a whole has an inaccuracy in that some known BSRs were not included owing to the difficulty of finding a map with sufficient features for georeferencing and digitizing.
To assess the potential inaccuracy related to (a): The general criteria used to delineate BSRs in marine seismic data acquired with high-energy, impulsive acoustic sources having the frequency characteristics needed to image BSRs include such factors as: (1) negative polarity (reverse impedance, indicating higher over lower velocity sediments) reflections in marine sedimentary section within tens to hundreds of meters below the seafloor; (2) seismic reflections that sometimes roughly parallel the seafloor, consistent with their position at a depth where the hydrostatic pressure and temperature in the sediments correspond to the limit for gas hydrate stability conditions; and (3) seismic reflections that cut across stratigraphic layering, consistent with the reflections' marking a phase boundary, not a stratigraphic boundary, within the sediments. Other bottom simulating features are sometimes recognized in marine seismic data (e.g., the transition of quartz to opal-CT), but such features have different impedance and depth characteristics than BSRs associated with gas hydrates. For the published papers used as the source of maps for georeferencing and digitization of the BSRs, all had been subject to peer review, and gross misidentification of opal-CT features as hydrate-related BSRs is unlikely. There is considerable subjectivity in authors' delineations of BSRs on maps, especially when polygons are drawn encompassing areas in which the raw data indicate fragments of recognized BSRs along individual seismic lines. How much of the area does not contain BSRs within the polygons on original maps is unknown. For Mosher2011_EasternCanada, Bialis2022_BlackSea, and Minshull2020_Norway the BSRs in the original publications were respectively indicated only by circles, ovals, or small, nearly circular shapes on the original maps, meaning that more precise locations and/or spatial extents of BSRs are unknown. Polygons around areas containing BSRs in the original publications often have square edges (possibly correlating to the extent of the original seismic data) or are truncated at the edge of a map, and the original maps associated with BenAvraham2022_SouthAfrica and Neben1998_CelebesSea have question marks on parts of the BSR polygons. Some publications map BSRs not as polygons, but as line segments or points along seismic lines at the places where BSRs are recognized. The publications associated with Jin2003_SouthShetland and Kopp2002_Sumatra show squares over BSRs mapped on seismic lines, and the original maps for Trehu2022_Cascadia, Chi2006_Taiwan, Liu2006_Taiwan, Ohde2018_Nankai, and some others have BSR points along seismic lines. Especially for cases in which the published maps use a polygon to enclose an area where BSRs have been recognized, the delineation of the polygon is likely to represent the greatest inaccuracy in terms of where BSRs actually exist. Note that there are two or more maps for some locations in the dataset. Examples (not exhaustive list) include the Black Sea (Bialis2022_BlackSea, Ludmann2004_BlackSea, and Vasilev2002_BlackSea), the South China Sea (Li2013_SouthChinaSea and Wang2022_SouthChinaSea), Nankai (MH212009_Japan files and Ohde2018_Nankai), and offshore India (Kumar2014_India files and Prakash2010_IndiaEast) have two or more that features within the BSR_polygons layer within the GeoPackage. Users can compare the extent of the BSRs in these maps (in some cases, the BSR polygons will be seen to overlap) and note the differences, but no value judgment was placed by the dataset's authors on the relative accuracy of one of these maps over another.
To assess the potential inaccuracy associated with (b): Georeferencing and digitizing BSRs from maps published over a period of more than 30 years in a wide range of journals and from many geographic areas are not the preferred method for compiling a global dataset, but rather the only method possible when the digital files are unavailable from the original authors. High-quality georeferencing was difficult for BSRs at high latitudes, for maps that were originally published in projections that distorted geometric relationships, and for maps lacking coastlines. The quality of digitization can vary from map to map as well, depending on slight variations in manually picking the points to digitize. It is not possible to quantitatively determine the degree of inaccuracy resulting from georeferencing and digitization, but georeferencing inaccuracies will almost always exceed digitizing inaccuracies.
To assess the potential inaccuracy related to (c): Subjective decisions were made during the digitization process, especially when representing BSRs that appeared in the original published maps as points along seismic lines. For most published maps, polygons in the original were digitized as polygons, and polygons were not combined during digitization. For BSRs identified as points along seismic lines in references such as Chi2006_Taiwan, Liu2006_Taiwan, and Ohde2018_Nankai, polygons were drawn around areas where the BSR points were identified, and the polygon outlines were digitized. Trehu2022_Cascadia and Trehu2022_Hydrate Ridge come from the same published map, which has BSR points identified along seismic lines. For the former file, the points were combined into line segments where BSRs were present on the seismic lines and digitized as polylines. For Hydrate Ridge, which was densely covered by BSR points identified along seismic lines, a polygon was drawn encompassing the dense cluster of points and then digitized. When the dataset authors drew polygons for digitization around points or line segments where BSRs were recognized in original seismic data, this was done judiciously to ensure that large areas without BSR indicators would not be included within the polygons. However, drawing such polygons does introduce an additional inaccuracy.
Note that the two entries associated with BOEM_USAtlantic were provided to the U.S. Geological Survey by the Bureau of Ocean Energy Management (BOEM) as digital coordinates, meaning that there is no inaccuracy associated with (b) or (c) for these BSRs. The entries associated with Shedd2012 were similarly provided by BOEM as shapefiles so that there is also no inaccuracy related to (b) or (c).
BSRs are known to exist in some locations where no published map could be found or where published maps lacked features making it possible to georeference and digitize the maps. For example, BSRs exist offshore parts of Antarctica, but published maps could not be georeferenced for this dataset. BSRs are known to be far more extensive offshore eastern Canada than indicated by the one publication included in this dataset, but no maps have been published, perhaps because the underlying data described in the reference for Mosher2011_EasternCanada are proprietary.
Except for the Kvenvolden1990 map digitized by Carolyn Ruppel in 2013, each of the original maps that required digitization was georeferenced and digitized using the same process and by the same researcher (A. How). In every case, features plotted from the resulting shapefiles overlapped the comparable features in the original maps in the geographic information systems software and had plausible latitudes and longitudes. When these features were plotted on a global map, they resembled the extent and morphology of the maps in the original publications. Polygons were verified to be closed shapes without extraneous components. Because this dataset combines a number of sources, overlapping polygons exist and are valid.
The GeoPackage contains all of the BSRs that were successfully georeferenced and digitized and the additional files provided directly by the Bureau of Ocean Energy Management in geographic coordinates or as shapefiles.
Spatial inaccuracy could result from a variety of factors discussed in detail in this metadata under geographic accuracy. Spatial inaccuracy could include problems with the accuracy of original information and with the digitization processes.
STEP 1: In most cases, maps showing the areal extent of bottom simulating reflections (BSRs) were extracted from digital copies of published manuscripts as JPEG (Joint Photographic Exports Group) or PNG (Portable Network Graphics) files and named with the convention of lead author of the publication followed immediately by the publication year then an underscore symbol and the geographic location of the BSRs. Two maps (labelled "MH21" and "Praeg2018") were taken directly from websites. Files labelled "BOEM" and "Shedd2012" were provided in already digitized form by the Bureau of Ocean Energy Management (BOEM). Processing date indicates approximate date of first recent map extraction with the exception of a map digitized by Carolyn Ruppel in 2013 (Kvenvolden1990). Map extractions continued sporadically until January 2023.
20210601
Carolyn Ruppel
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2339
508-457-2310
cruppel@usgs.gov
STEP 2: Each map was imported into a geographic information system using QGIS software (final version used QGIS 10.20.1 - Odense on a Windows 10 machine). Using coastlines (when available) and latitude and longitude control points (when indicated on the map), each map was georeferenced and the resulting shapefile saved. Processing date indicates approximate date of first georeferencing for the whole dataset. Processing continued sporadically until January 2, 2023, with some files reprocessed if the resulting shapefile did not credibly reproduce the original map.
20210806
Amelia How
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2215
508-457-2310
ahow@usgs.gov
STEP 3: Digitized BSRs not in the WGS84 geographic coordinate system were converted to WGS84 using Esri ArcMap 10.7 on a Windows 10 machine. The files provided by the Bureau of Ocean Energy Management (see Step 1) were also converted from NAD83 to WGS84 as needed. Processing date indicates the first date on which files were converted. This processing step was finished in early January 2023.
20221229
Carolyn Ruppel
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2339
508-457-2310
cruppel@usgs.gov
STEP 4: Shapefiles (originally 54) and an associated spreadsheet containing information about the quality of the georeferencing, the reference for the published bottom simulating reflections (BSRs), and comments related to the file were compiled for further processing. Using QGIS 3.16.7-Hannover running on a Windows 10 machine, each polygon shapefile (originally 52) and polyline shapefile (2) were checked for validity using the Vector Geometry tool – Check validity. Two polygons were found to have problems (Chand2012_Barents and Wang2022_SouthChinaSea), and these files were edited and repaired. Shapefiles that consisted of more than one polygon were combined into a single multipart polygon. This was accomplished using the tool Vector geometry – dissolve. As a result of this process, each shapefile contained only one feature. The same process was applied to the polyline shapefiles. Each shapefile was then edited to remove all attributes except the attribute id. A new text attribute was added “shpname” which was populated with the shapefile name prefix originally provided.
20230112
VeeAnn A. Cross
U.S. Geological Survey, Northeast Region
Marine geologist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2251
508-457-2310
vA.@usgs.gov
STEP 5: Using the QGIS software referenced in Step 4, the polygon shapefiles were then merged into a single polygon shapefile using the Vector General tool – Merge vector layers. The output polygon shapefile was named merged_polygons.shp. The same procedure was followed for the 2 polyline shapefiles with the output shapefile named merged_polylines.shp
20230112
VeeAnn A. Cross
U.S. Geological Survey, Northeast Region
Marine geologist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2251
508-457-2310
vA.@usgs.gov
STEP 6: Using the QGIS software referenced in Step 4, the polygon shapefile was then joined to the Excel spreadsheet containing additional information about the shapefiles (see Step 4) in order to bring over the additional attributes needed for the dataset. The join was accomplished using the Vector general tool – Join attributes by field value. The attribute in the shapefile to join to was shpname corresponding to the column in the Excel spreadsheet named "shapefile." The results were saved into a temporary layer in QGIS. This same join procedure was followed for the polyline merged shapefile and saved as a temporary layer in QGIS.
20230112
VeeAnn A. Cross
U.S. Geological Survey, Northeast Region
Marine geologist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2251
508-457-2310
vA.@usgs.gov
STEP 7: Using the QGIS software referenced in Step 4, the polygon temporary layer was then exported to a GeoPackage using Export – Save feature as. Format – GeoPackage. Filename - BSR_GeoPackage.gpkg. Layer name – BSR_polygons. The polyline temporary layer was then exported to the same GeoPackage. Right-mouse click on the layer name – Export – Save feature as. Format – GeoPackage. Filename - BSR_GeoPackage.gpkg. Layer name – BSR_polylines.
20230112
VeeAnn A. Cross
U.S. Geological Survey, Northeast Region
Marine geologist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2251
508-457-2310
vA.@usgs.gov
STEP 8: Using QGIS software 3.22.14 - Bialowieza on a Windows 10 machine, the attribute tables for the two layers in the GeoPackage were edited to delete unneeded or redundant columns, to resolve small errors in location descriptions, and to reorder the columns in the attribute table (using "processing > refactor"). In addition, the Excel file was reordered for better correlation with the order of the feature files within the layers for the GeoPackage, and the GeoPackage attributes pointing to the Excel file numbering were manually updated using QGIS. Edits were also made to increase the uniformity of the reference formats and to reduce the number of retained digits for some of the latitude and longitude entries. One record was removed due to low quality georeferencing and the map's being superseded by a co-located and more complete BSR map in another publication. This resulted in the fid within the attribute table being non-sequential (#42 is skipped), reduced the number of polygons to 51 and the total number of features to 53. The process date is the first date on which the files were edited to bring the GeoPackage and the Excel file into conformity.
20230116
Carolyn Ruppel
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
US
508-458-8700 x2339
508-457-2310
cruppel@usgs.gov
Vector
0.0197427722
0.0261514554
Decimal seconds
WGS_1984
WGS_84
6378137.0
298.257223563
BSR_polygons
polygon entries (single and multipart) for bottom simulating reflectors (BSRs), containing 51 records
U.S. Geological Survey
fid
Internal feature number. Whole numbers that are automatically generated. Number 42 is missing from the polygon features, resulting in non-sequential fid.
QGIS
1
52
shpname
Name of feature, in format of first author of original reference and year of publication followed by underscore and then a generalized area descriptor. Three locations have multiple bottom simulating reflection (BSR) polygon layers from the same references, but with characteristics appended after the geographic descriptor. "MH212009_Japan" layers are labelled "confirmed" (corresponding to the original map's "methane hydrate concentrated zones are confirmed partially by detailed surveys" shown in red polygons), "suggested" (corresponding to the original map's "characteristics of methane concentration are suggested in some areas" shown in navy blue polygons), "low" (corresponding to the original map's "characteristics of methane concentration are not recognized" shown in green polygons), and "unknown" (corresponding to the original map's "surveys are insufficient for the evaluation of methane hydrate" shown in light blue polygons). "Shedd2012_GulfofMexico" layers are labelled "continuous," "discontinuous," and "pluming" based on the BSR designations in the original publication. "BOEM2012_USAtlantic" layers are labelled "high" to indicate strong confidence in the existence of BSRs and "possible" to indicate lesser confidence in the BSRs, based on the original publication. "Kumar2014_India" layers are labelled "high," "medium," and "low" corresponding to red polygons (highly prospective for gas hydrates), green polygons (moderately prospective), and yellow polygons (low prospectivity) on the original map.
Producer defined
ASCII text
geometry
Geometry of feature, with "polygon" indicating single or multipart polygon.
Producer defined
ASCII text
fileid
Whole number identifying corresponding entry in Excel file.
Producer defined
1
51
location
Text field providing up to three location designations separated by dashes, starting with the most general and progressing to the most specific. For marine locations, the first designator refers to the appropriate ocean or basin. For onshore locations (permafrost or Lake Baikal), the first designator refers to the country. Some locations have a designator that includes a slash ("/"). This is the case for the Sea of Japan/East Sea or East Sea/Sea of Japan since this same body of water is referred to using both names, usually dependent on the nationality of the lead author of the associated reference.
Producer Defined
ASCII text
central_long
Decimal degrees corresponding to the average of the minimum and maximum longitudinal extent of each polygon feature, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-149.24153
176.41938
decimal degrees
central_lat
Decimal degrees corresponding to the average of the minimum and maximum latitudinal extent of each polygon feature, with positive denoting north latitude and negative denoting south latitude.
Producer defined
-61.13465
79.90192
decimal degrees
minlong
Decimal degrees corresponding to the minimum longitudinal extent of each polygon feature, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-158.57649
173.78199
decimal degrees
maxlong
Decimal degrees corresponding to the maximum longitudinal extent of each polygon feature, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-139.90657
179.05677
decimal degrees
minlat
Decimal degrees corresponding to the minimum latitudinal extent of each polygon feature, with positive denoting north latitude and negative denoting south latitude.
Producer defined
-61.51265
78.265099
decimal degrees
maxlat
Decimal degrees corresponding to the maximum latitudinal extent of each polygon feature, with positive denoting north latitude and negative denoting south latitude.
Producer defined
-60.75665
81.53874
decimal degrees
reference
Text field that contains the figure number and citation for the scientific work from which the bottom simulating reflectors (BSRs) are taken, including the digital object identifier (DOI) or URL when available.
Producer Defined
ASCII text
quality
Whole number indicating subjective evaluation of the quality of the bottom simulating reflections (BSRs) shapefile generated for each feature in this data set, based on consideration of difficulties with georeferencing, whether the BSRs are truncated or too generalized in the original map, and related factors.
Producer Defined
1
Denotes the best quality and is only used for files provided directly by the Bureau of Ocean Energy Management, already in geographic or projected coordinates (known projection).
Producer Defined
2
Used for most BSRs based on the likelihood of imprecisions in georeferencing and digitizing.
Producer Defined
3
Indicates the worst quality and is assigned for high latitude or other locations that were particularly difficult to georeference or for maps that provided only general indications about the location of BSR features (e.g., circles or ovals around areas with BSRs).
Producer Defined
comments
Text field with additional notes about the original map or the georeferencing or digitization. Not all records have a comment.
Producer Defined
ASCII text
filegen
Who generated the feature, in which year, and how.
Producer Defined
ASCII text
BSR_polylines
polyline entries for bottom simulating reflectors (BSRs), containing 2 records
U.S. Geological Survey
fid
Internal feature number. Whole numbers that are automatically generated.
QGIS
1
2
shpname
Name of feature, in format of first author of original reference and year of publication followed by underscore and then a generalized geographic descriptor.
Producer defined
ASCII text
geometry
Geometry of layer, with "polyline" indicating line features.
Producer defined
ASCII text
fileid
Whole number identifying corresponding entry in Excel file.
Producer defined
52
53
location
Text field providing up to three location designations separated by dashes, starting with the most general and progressing to the most specific. The first designator refers to the appropriate ocean or basin.
Producer Defined
ASCII text
central_long
Decimal degrees corresponding to the average of the minimum and maximum longitudinal extent of each polyline, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-125.993959
150.02577
decimal degrees
central_lat
Decimal degrees corresponding to the average of the minimum and maximum latitudinal extent of each polyline, with positive denoting north latitude and negative denoting south latitude.
Producer defined
44.643149
52.409875
decimal degrees
minlong
Decimal degrees corresponding to the minimum longitudinal extent of each polyline, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-127.423939
144.03115
decimal degrees
maxlong
Decimal degrees corresponding to the maximum longitudinal extent of each polyline, with positive denoting east longitude and negative denoting west longitude.
Producer defined
-124.563978
156.020391
decimal degrees
minlat
Decimal degrees corresponding to the minimum latitudinal extent of each polyline, with positive denoting north latitude and negative denoting south latitude.
Producer defined
40.280268
47.509814
decimal degrees
maxlat
Decimal degrees corresponding to the maximum latitudinal extent of each polyline, with positive denoting north latitude and negative denoting south latitude.
Producer defined
49.006031
57.309937
decimal degrees
reference
Text field that contains the figure number (where applicable) and citation for the scientific work from which the bottom simulating reflectors (BSRs) are taken, including the digital object identifier (DOI) or URL when available.
Producer Defined
ASCII text
quality
Whole number indicating subjective evaluation of the quality of the bottom simulating reflections (BSRs) shapefile generated for each feature in this data set, based on consideration of difficulties with georeferencing, whether the BSRs are truncated or too generalized in the original map, and related factors.
Producer Defined
1
Denotes the best quality and is only used for files provided directly by the Bureau of Ocean Energy Management, already in geographic or projected coordinates (known projection).
Producer Defined
2
Used for most BSRs based on the likelihood of imprecisions in georeferencing and digitizing.
Producer Defined
3
Indicates the worst quality and is assigned for high latitude or other locations that were particularly difficult to georeference or for maps that provided only general indications about the location of BSR features (e.g., circles or ovals around areas with BSRs).
Producer Defined
comments
Text field with additional notes about the original map or the georeferencing/digitization.
Producer Defined
ASCII text
filegen
Who generated the feature, in which year, and how.
Producer Defined
ASCII text
U.S. Geological Survey - ScienceBase
mailing address
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
United States
1-888-275-8747
sciencebase@usgs.gov
The release contains the GeoPackage (USGS_DigitizedBSRs_GeoPackage.gpkg), the Excel file (USGS_DigitizedBSRs_table.xlsx), the browse graphic (BSRbrowsegraphic.png), and associated FGDC CSDGM metadata in XML format.
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.
GeoPackage
QGIS 3.16.7-Hannover
GeoPackage containing two layers, one with polyline features and one with polygon features
The GeoPackage contains all the features, as well as attribute information that includes the location, the original published reference, a quality factor, how the feature was generated, and the minimum and maximum latitude and longitude bounds for each feature. Note that opening the GeoPackage in Esri software will reveal an attribute table with the second column labelled "geom." This particular column will not be present in the QGIS version or in the Excel spreadsheet. The attribute table contains a "geometry" column after the "shpname" in any version of the Geopackage and in the Excel spreadsheet.
2
https://www.sciencebase.gov/catalog/file/get/63caaf8cd34e06fef14f3e2a
https://www.sciencebase.gov/catalog/item/63caaf8cd34e06fef14f3e2a
https://doi.org/10.5066/P9IW5CL7
The first link in network resources downloads all the data to a zip file. The second link goes to the landing page of the dataset where individual files can be downloaded manually, and the third link points to the main data release landing.
XLSX
Microsoft Office Excel 365
GeoPackage containing two layers, one with polyline features and one with polygon features
The dataset contains a GeoPackage with the spatial representation of the digitized BSR locations (polygon and polyline), as well as attribute information that is also contained in the Excel spreadsheet. A browse graphic and CSDGM metadata are also included.
2
https://www.sciencebase.gov/catalog/file/get/63caaf8cd34e06fef14f3e2a
https://www.sciencebase.gov/catalog/item/63caaf8cd34e06fef14f3e2a
https://doi.org/10.5066/P9IW5CL7
The first link in network resources downloads all the data to a zip file. The second link goes to the landing page of the dataset where individual files can be downloaded manually, and the third link points to the main data release landing.
None
These data are available as an open, portable, platform-independent GeoPackage. The user must have software capable of reading this format. Note that reading the GeoPackage in Esri software will show "geom" added as a second column by the software in the attribute table. The Excel file provided with the GeoPackage contains the attributes for the GeoPackage (without this additional column introduced by Esri software) in an alternate format and requires Microsoft Office software for access. The data are available for download in zip format, which requires software to extract the files from the zip archive.
20230202
Carolyn Ruppel
U.S. Geological Survey, Northeast Region
Research Geophysicist
mailing address
384 Woods Hole Road
Woods Hole
MA
02543
United States
508-458-8700 x2339
whsc_data_contact@usgs.gov
The metadata contact email address is a generic address in the event the person is no longer with USGS.
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998