GeoPackage of Seabed Hazards for Offshore Infrastructure, U.S. Atlantic and Pacific Continental Shelves

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What does this data set describe?

1. How might this data set be cited?
   Curran, Brian J., and Brothers, Laura L., 20250805, GeoPackage of Seabed Hazards for Offshore Infrastructure, U.S. Atlantic and Pacific Continental Shelves: data release DOI:10.5066/P1SLUTW9, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

   Online Links:

   • https://doi.org/10.5066/P1SLUTW9
   • https://www.sciencebase.gov/catalog/item/67dacd32d34ef1653388702f

   Other_Citation_Details:

   Suggested citation: Curran, B.J., and Brothers, L.L., 2025, GeoPackage of seabed hazards for offshore infrastructure, U.S. Atlantic and Pacific continental shelves: U.S. Geological Survey data release, https://doi.org/10.5066/P1SLUTW9

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -126.00014
   East_Bounding_Coordinate: -60.09880
   North_Bounding_Coordinate: 47.22849
   South_Bounding_Coordinate: 24.00704
   

3. What does it look like?

   https://www.sciencebase.gov/catalog/file/get/67dacd32d34ef1653388702f/?name=GOM_BOEM_OCS_A0567.png&allowOpen=true (PNG)

   Sea floor topography in and around BOEM lease area OCS-A-0567 exhibiting many sea-floor hazards.

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

   Beginning_Date: 1972

   Ending_Date: 2024

   Currentness_Reference:

   The dates represent the range of publication dates of the data used in this compilation.

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

   Geospatial_Data_Presentation_Form: vector digital data (polygon) and tabular data
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Vector 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 1984.
      The ellipsoid used is WGS 84.
      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?

   TD_GHZD_FC

   This feature class consists of publicly available studies examined for geohazards. Identified hazards were categorized according to seven classifier types described below. There are 179 records in this dataset. (Source: Producer defined.)

   OBJECTID

   Unique value corresponding to the record within the dataset. May or may not be visible depending on the software package used to view the data. (Source: Software defined.) Text.

   Shape

   Attribute used to store the geometry of the record. May or may not be visible depending on the software package used to view the data. (Source: Software defined.) Text.

   TITLE

   Title of the study, report, or geospatial data that provided the data and information. (Source: Producer defined.) Text.

   AUTH

   The complete list of authors of the study, report or data on which the record is based in the format Last Name, First Initial, Middle Initial (if available). Sequential authors are separated by a comma. (Source: Producer defined.) Text.

   PUB_Y

   Publication year of the information source. (Source: Producer defined.)

   Range of values
   Minimum:	1972
   Maximum:	2024

   DOI

   DOI number if available of the information source, NULL if not available. (Source: Producer defined.) text

   LINK

   URL of the source referred to by the title, using a DOI link when available and viable. (Source: Producer defined.) text

   ACCESS

   The most recent date in the format MM/DD/YYYY (in the database as YYYY-MM-DD) that the source was accessed for the information used in the dataset. (Source: Producer defined.) text

   MOBBED

   Any seabed exhibiting bedforms, evidence of scour or other bedform migration. This class identifies areas where mobile bedforms are present or likely to occur, based on seabed morphology (e.g., ripples, sand waves, megaripples, sand ridges) and associated depositional or hydrodynamic processes. Interpretations may reflect the presence, type, geometry, and spatial distribution of bedforms; evidence of bedform migration or orientation; and indicators of sediment transport pathways and availability of sediment supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or the distribution and thickness of sediment units conducive to bedform formation. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   MOBBED_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   HARDBOT

   Refers to any sea floor consisting of surface boulders, glacial till, moraines, outcrops, reefs, exposed rocky areas, shallow bedrock, or indurated sediments. This class identifies areas where hard substrate is present at or beneath the sea floor, typically within the upper 50–100 meters below sea floor (bsf). These materials may include bedrock, boulders, coarse glacial or fluvial deposits (e.g., moraines, till), and semi-consolidated to indurated sediments such as cemented sands or clays.
   Biogenic substrates such as reefs or shelly sediments are also included when they contribute to substrate hardness or could pose potential construction challenges.
   Hard substrates may be exposed at the surface or inferred from geophysical data. In the subsurface, indicators such as prominent acoustic reflectors or penetration resistance are used to constrain the depth, lateral extent, or thickness of these units. Their presence is relevant to foundation design and cable burial feasibility. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   HARDBOT_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   SED

   This class identifies areas where seabed sediment characteristics may pose challenges to installation, operation, or decommissioning. It includes geochemical, geotechnical, and geophysical properties that may affect component installation, long-term structural integrity, or decommissioning activities. Key concerns include soil fatigue, obstructive material, low strength, liquefaction potential, poor heat dissipation, and heterogeneity that increases design uncertainty.
   Where possible, these conditions are contextualized within the broader geologic framework, particularly in relation to regressive and transgressive intervals that form features such as paleochannels and stratigraphic sequences. Identification of seismic reflectors helps constrain the spatial distribution and thickness of these units within the framework.
   Units of concern include organic-rich sediments (e.g., muds, peat), carbonate-rich material, and under consolidated deposits such as paleochannel fill, deltaic, lacustrine, or estuarine sediments. Such material may be prone to liquefaction, scarp or deform along natural failure planes, or exhibit differential settlement. Glauconite-bearing material is also included for its potential to resist penetration or contribute to pile refusal. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   SED_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   SLOPE

   This class identifies areas where slope gradients or mass movement features may present a hazard to offshore development. It includes sea floor expressions of current or past instability such as debris flows, slumps, slides, and mass transport scarps.
   Where available, bathymetric grids and sea floor topography maps are referenced to support interpretation. These datasets help identify areas of pronounced rugosity or steep relief that may overlap with other geomorphic features (e.g., sand ridges, bedrock promontories) and serve as indicators of slope-related hazards even where other geohazard interpretations are limited. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   SLOPE_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   GAS

   This class identifies areas where gas is present or suspected within sea floor or shallow subsurface sea-floor sediments. The presence of gas may affect component installation, long-term structural stability, and decommissioning activities for renewable infrastructure. Indicators may include direct observations such as water column anomalies, seismic acoustic blanking, as well as sea floor expressions like pockmarks or seepage features.
   Gas occurrences may result from biogenic or thermogenic processes and are not necessarily confined to shallow or recent deposits. Gas hydrates—solid crystalline structures of gas and water—may be present where pressure and temperature conditions allow. Some entries infer the presence of gas through its association with known stratigraphic units—such as estuarine or fluvial Holocene deposits—even when not explicitly identified in the source data. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   GAS_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   STRUCT

   This class identifies areas where structural or tectonic features may influence subsurface conditions relevant to offshore development. These features are typically interpreted from seismic or sub-bottom data and include faults, deformation zones, glaciotectonic structures, and other disruptions to stratigraphy. They may represent active or relict processes and can occur at a range of depths within the geologic column.
   Structural elements may result from tectonic activity, glacial thrusting, salt or mud diapirism, or other mechanisms that cause vertical or lateral displacement of sediments. These features may coincide with other geohazards such as surficial fault expressions or gas-escape conduits. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   STRUCT_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   ANTH

   Refers to hazards or obstructions of anthropogenic origins. This class identifies anthropogenic features or administrative boundaries that may influence site suitability or require avoidance during offshore development. These include known or interpreted objects such as shipwrecks, cables, pipelines, dredge material, UXO/MEC (unexploded ordnance/munitions of explosive concern), other sea floor infrastructure, and non-physical administrative or jurisdictional zones such as dumping grounds or anchorage areas.
   Physical features may be identified through bathymetric or sub-bottom data, public repositories, or other records. Minor anthropogenic features such as trawl marks were not typically recorded in public repositories but are noted where they were identified by native datasets. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no interpretation available.
   Y	Positively identified or inferred from supporting evidence in the source material.

   ANTH_N

   Free-text field containing source-specific notes or interpretation details related to the classification. (Source: Producer defined.) text

   UNID

   unique ID for the record in the format 'TD' plus a 4-digit number ranging from 0001 to 0179 which represents the unique OBJECTID for the record. (Source: Producer defined.) formatted text

   DOMAIN_M

   These values represent the method or methods used to create geometry for each entry with respect to the data source. An individual source might employ more than one method, and each method used will be separated by an '_' in the database attribute table. The sequence of designations within each DOMAIN_M entry reflects a general order of data origin, data model, and processing steps. The first one or two elements typically describe the source and format of the original data, while subsequent elements represent processing steps. Processing steps include: MA, SG, and B. (Source: Producer defined.)

   Value	Definition
   B	The domain was created by applying a buffer around a feature, such as a 10 km buffer around a coast.
   DPR	The domain was derived, unaltered, from reputable and publicly accessible repositories, such as government, academic, or organizational data portals (e.g., USGS or NOAA) and only applies to vector format source data. The original geometry was preserved and reprojected into the Geographic Coordinate System (GCS) WGS 1984 to standardize spatial references.
   GF	The domain was digitized after georeferencing a non-geospatial image into a spatial reference system.
   MA	The domain was edited manually to refine boundaries or fix inconsistencies.
   NAT	The domain was created, in part, using original geospatial data layers such as rasters, shapefiles, or other GIS data. The data type employed is specified by the second-order element which immediately follows, e.g., 'R' or 'V'.
   R	The domain was created in part using the domain of original geospatial raster data such as bathymetry.
   SG	The domain was created by simplifying complex geometries, for easier analysis or visualization. This may utilize simplification methods such as minimum bounding geometry (featuring geometry types such as convex hull and envelopes), simplify polygon, and smooth polygon.
   V	The domain was created in part using the domain of native manual or automated interpretations of vector data, such as geological polygons or habitat boundaries. This element does not pertain to administrative or political boundaries from external sources.
   VBD	The domain boundary was based on vector data of natural or artificial features, such as coastlines or administrative limits derived from sources external to the original study.

   OI_GHZD_Polygons

   A vector feature class representing active lease areas, investigation areas, and export cable corridors. There are 54 records in this dataset. (Source: Producer defined.)

   OBJECTID

   Unique value corresponding to the record within the dataset. May or may not be visible depending on the software package used to view the data. (Source: Software defined.) Text.

   Shape

   Attribute used to store the geometry of the record. May or may not be visible depending on the software package used to view the data. (Source: Software defined.) Text.

   LEASE_NUMB

   Lease number assigned to the polygon according to their BOEM designation. Records starting with NYS are text only and refer to the NYSERDA source. Alphanumeric values beginning with OCS are source from BOEM - Outer Continental Shelf lease block. (Source: Producer defined.) text

   UNID_P

   unique ID for the polygon record; in the format 'O' plus a unique number ranging from 1001 to 1054 which represents the unique OBJECTID for the record. This value is used to provide a one-to-many relationship between the OI_GHZD_Polygons dataset and the OI_GHZD_Table dataset. (Source: Producer defined.) formatted text

   DOMAIN_M

   These values represent the method or methods used to create geometry for each entry with respect to the data source. An individual source might employ more than one method, and each method used will be separated by an '_' in the database attribute table. The sequence of designations within each DOMAIN_M entry reflects a general order of data origin, data model, and processing steps. The first one or two elements typically describe the source and format of the original data, while subsequent elements represent processing steps. (Source: Producer defined.)

   Value	Definition
   B	The domain was created by applying a buffer around a feature, such as a 10 km buffer around a coast.
   DC	The study domain was georeferenced and digitized to a point using coordinates provided in the source material.
   DPR	The domain was derived, unaltered, from reputable and publicly accessible repositories, such as government, academic, or organizational data portals (e.g., USGS or NOAA) and applies to vector format source data. The original geometry was preserved and reprojected into the Geographic Coordinate System (GCS) WGS 1984 to standardize spatial references.
   GF	The domain was digitized after georeferencing a non-geospatial image into a spatial reference system.
   MA	The domain was edited manually to refine boundaries or fix inconsistencies.
   NAT	The domain was created, in part, using original geospatial data layers such as rasters, shapefiles, or other GIS data. The data type employed is specified by the second-order element which immediately follows, e.g., 'R' or 'V'.
   R	The domain was created in part using the domain of original geospatial raster data such as bathymetry.
   SG	The domain was created by simplifying complex geometries, for easier analysis or visualization. This may utilize simplification methods such as minimum bounding geometry (featuring geometry types such as convex hull and envelopes), simplify polygon, and smooth polygon.
   V	The domain was created in part using the domain of native manual or automated interpretations of vector data, such as geological polygons or habitat boundaries. This element does not pertain to administrative or political boundaries from external sources.
   VBD	The domain boundary was based on vector data of natural or artificial features, such as coastlines or administrative limits derived from sources external to the original study.

   OI_GHZD_Table

   Non-spatial table containing geohazard classifications and descriptions derived from infrastructure site investigations and developer-submitted documents. There are 1836 records in this table. (Source: Producer defined.)

   LEASE_NUMB

   Lease number assigned to the polygon according to their BOEM designation. Records starting with NYS are text only and refer to NYSERDA sources. Alphanumeric values beginning with OCS are source from BOEM - Outer Continental Shelf lease block. (Source: Producer defined.) text

   GHZD

   Geohazard classification representing the type of geological or geotechnical hazard identified within a given spatial domain. The presence of these features may interfere with the installation and stability of foundations and cables associated with construction. Values are assigned based on interpretation of developer-submitted documents and are represented by 34 unique values. These values can be loosely grouped into seven distinct classifications. These classifications are ANTHR (refers to hazards or obstructions of anthropogenic origins), GAS (refers to the presence of shallow gas, gas seeps, pockmarks or gas hydrates), HARDBOT (refers to any sea floor consisting of surface boulders, glacial till, moraines, outcrops, reefs, exposed rocky areas, shallow bedrock, or indurated sediments), SLOPE (refers to the occurrence of slumps, slides, mass transport scarps, or steep slopes); MOBBED (refers to any seabed exhibiting bedforms, evidence of scour or other bedform migration); STRUCT (refers to evidence of seismic activity such as faults and fault scarps); and SUBSURF (refers to occurrences of organic soil, peat, glauconite, buried channels and evidence of subsurface deformation in the upper tens of meters of the sea floor). Each of these classifications has further refined elements that are used as values in the attribute and defined below. The loose classification defined above is in parentheses for the appropriate value in the subsequent definitions. Of note: There are 2 implied relationships with respect to these values. The attribute value for 'Bedform migration' has an attribute value set for IDEN if the following condition is met: one or more of the following GHZD attribute values has an IDEN value of 'Y' - Megaripples, Ripples, Sand ridges, Sand waves, Unclassified bedforms. However, it is possible for Bedform migration to have an IDEN value of 'Y', and none of those specific GHZD IDEN values of 'Y' depending on the source of information and what specificity is included in that source. In a similar manner, the attribute value for GHZD Glacial till has the IDEN value set to 'Y' if that same comprehensive location has a GHZD Moraine IDEN value set to 'Y'. The presence of Glacial till does not necessarily mean the presence of a Moraine. (Source: Producer defined.)

   Value	Definition
   Anchorages, dumping grounds, disposal sites	(ANTHR) Human-made objects or designated use zones that that may present a physical or administrative boundary to offshore development activities. These specific items for this classification are anchorages, dumping grounds and disposals sites on the sea floor typically identified from sonar imagery, magnetometer data, seismic reflection profiles, or public inventories.
   Areas Prone to scour	(MOBBED) Areas where sediment removal by hydrodynamic forces is likely to occur or has been observed. Scour processes may reduce sediment cover or undercut foundations. This classification includes both localized scour (e.g., around boulders, debris, or structures) and broader areas. Interpretations may be based on direct observation of scour features or inferred from environmental conditions such as high current velocity, exposed substrates, coarse-grained soils, or sparse sediment cover. Areas may be classified as prone to scour even when specific features are not resolved, if the hydrodynamic setting or sediment context suggests increased erosion potential based on information in the source material documentation.
   Bedform migration	(MOBBED) Any sea floor where bedforms are observed to migrate on an engineering timescale. This classification is based on the interpreted or observed movement of bedforms across the sea floor, whether based on repeat survey comparison, sediment transport modeling, or direct mention in the source material. This classification may be used to document active migration or the absence of movement. Migration may involve isolated features or entire bedform fields and is often used to infer forcing activity, sediment availability, or stability of the seabed.
   Buried channels	(SUBSURF) Paleochannels are complex stratigraphic features which typically contain a heterogeneous infill of soft muds, peats, organics, and coarse lag which fill ancient river or inlets that have been buried by the younger sediment. They present unique challenges in predicting subsurface conditions as their geometry, infill material, and internal stratigraphy often vary significantly over short distances. Seismic reflection profiling and geotechnical sampling are used to interpret these features within the broader geologic framework.
   Cables	(ANTHR) This class is one of several which identify known or interpreted anthropogenic features or boundaries. This class identifies known or interpreted cables on or near the seafloor. These features are typically derived from sonar imagery, magnetometer data, or public inventories. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material.
   Fault scarps	(STRUCT) Surficial expressions of faults, one of several classes part of the broader group of structural features. These features are characterized by linear breaks or steps and may mark the expressions of underlying fault structures and therefore may overlap with other hazard classes. These features are identified using sonar data, but their geometry, extent, and activity may be further characterized with seismic reflection profiles.
   Faults	(STRUCT) Refers to a planar fracture or discontinuity in a volume of rock, indurated sediment or consolidated sediment across which there has been significant displacement as a result of mass movements. These features are typically identified using seismic reflection profiles, which may reveal their geometry, extent, and activity. While sonar data may highlight surface expressions, such interpretations are more appropriately captured under the Fault Scarps class. Faults can deform overlying sediments and act as conduits for fluid migration, which may result in overlap with other hazard classes. In many cases, faults referenced in source material have been previously identified through legacy investigations or regional geologic studies.
   Gas hydrates	(GAS) A naturally occurring, ice-like substance that forms when water and gas combine under high pressure and at moderate temperatures. Methane is the most common gas present in gas hydrate, although other gases may also be included in hydrate structures, particularly in areas close to conventional oil and gas reservoirs. Gas hydrate is widespread in ocean-bottom sediments at water depths greater than 300–500 meters and is also present in areas with permanently frozen ground (permafrost). Gas hydrates may contribute to soil instability when disturbed. Interpretations of gas hydrates are derived from seismic reflection profiling.
   Glacial till	(HARDBOT) Poorly-sorted ice-contact sediments typically comprised of a dense mixture of clay, silt, sand, gravel, and cobble- to boulder-sized clasts. Till may exhibit high penetration resistance. It may also exhibit high soil heterogeneity due to complex depositional sequences and glacial reworking and deformation. The presence of till may be inferred using seismic reflection data, grab or core samples, and regional geologic framework context. It may occur on the sea floor or in the subsurface. Material which is characteristic of till is not always explicitly interpreted as such by the source. This class may overlap with other ice-contact classes such as moraines or boulder fields.
   Glauconite	(SUBSURF) Iron-potassium micaceous clay of the illite family that occurs in both ancient and modern marine environments. In this geopackage 'Glauconite' encompasses glauconite, glauconitic sands and green sands. Glauconite is deposited in low-energy marine settings and its authigenic form is typically found in marine deposits at the base of transgressive system sequences. Glauconite-bearing sediments may resist penetration and result in monopile refusal. Interpretations of glauconite-rich sediment are typically verified by geotechnical sampling and complemented by seismic reflection profiling.
   Mass transport scarps	(SLOPE) An abrupt change in relief related to a mass movement. These features are identified as surficial expressions of gravity-induced slope failure events, including landslides and debris flows. Sonar data may be used to identify steep escarpments and arcuate headwalls which are indicative of these features. Seismic reflection profiling may be used to further characterize their age, origin, extent, and the potential for future instability.
   Megaripples	(MOBBED) Medium-scale bedforms that have a wavelength of 5-60 meters and a height between 0.5-1.5 meters. However, this classification may also apply to megaripple-like features described in source material that lack defined geometry. While often associated with active sediment transport, features may also represent relict (non-mobile) forms preserved from past depositional conditions. Megaripple fields may occur in isolation or as part of larger bedform complexes (e.g., sand waves and sand ridges). Interpretations may reflect the presence, type, geometry, and distribution of bedforms; evidence of migration or orientation; and indicators of sediment transport and supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or sediment thickness conducive to ripple formation.
   Moraines	(HARDBOT) The accumulation of unsorted sediments deposited by a glacier typically as ridges, mounds, or irregular terrain at the edges or extremity of the glacier position. This class identifies areas where glacial moraines are present or inferred on the sea floor or in the shallow subsurface. Interpretations derived from the source material may be based on bathymetric and backscatter expression, sub-bottom reflectors, geologic mapping, or regional geologic context. This class may overlap with ice-contact classes such as glacial till or boulder fields.
   Organic soil	(SUBSURF) Refers to substrates rich in organic material, typically fine-grained (e.g., soft clays, silts) and low in shear strength. They are associated with low-energy depositional settings such as estuaries and lagoons. They may be prone to compression, differential settlement, and exhibit low bearing capacity. They may also be associated with gaseous sediments. Interpretations of organic sediment are typically verified by geotechnical sampling and complemented by seismic reflection profiling.
   Other seabed obstructions	(ANTHR) This class identifies anthropogenic features or boundaries not otherwise categorized—such as unidentified debris, anchors, or submerged infrastructure. These features may represent physical hazards, cultural resources, or administrative boundaries. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material. In some instances, these features or objects are identified in geophysical data and addressed in the source material.
   Outcrops, reefs, or exposed rocky areas	(HARDBOT) This classification includes natural bedrock outcrops, reef structures (biotic or abiotic), and other zones of exposed hardbottom. Features may present as ridges, scarps, elevated rock platforms, or irregular (e.g., hummocky) terrain, and are typically identified through sonar imagery, seismic reflection profiling, or regional geologic characterization. If identified in the subsurface, the depth of these features is sometimes constrained. This class is distinct from “Shallow Bedrock” in that it identifies only surficial expressions.
   Peat	(SUBSURF) This class identifies the presence of peat, which is a fibrous organic-rich sediment deposited in low-energy marsh or bog environments. Peats are highly compressible, exhibit low shear strength, and may present challenges to cable heat dissipation. Interpretations of peat are typically verified by geotechnical sampling and complemented by seismic reflection profiling.
   Pipelines	(ANTHR) This class identifies known or interpreted pipelines on or near the seafloor. These features are typically derived from sonar imagery, magnetometer data, or public inventories. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material.
   Pockmarks	(GAS) Sea floor craters usually associated with fluid or gas escape from seabed sediments. These features are typically identified through sonar data and may occur singly or in clusters. Due to their typically steep sidewalls, their presence can present both slope and gas-related hazards.
   Ripples	(MOBBED) small-scale bedforms typically less than 5 meters in wavelength and 0.5 meters in height, however, this classification may also apply to ripple-like features described in source material that lack defined geometry. While often associated with active sediment transport, features may also represent relict (non-mobile) forms preserved from past depositional conditions. Ripple fields may occur in isolation or as part of larger bedform complexes (e.g., megaripples, sand waves). Interpretations may reflect the presence, type, geometry, and distribution of bedforms; evidence of migration or orientation; and indicators of sediment transport and supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or sediment thickness conducive to ripple formation.
   Sand resource areas	(ANTHR) Refers to areas identified by BOEM as having sand that may be mined, and areas hosting active or inactive borrow sites. These areas designated for sand extraction are typically used for beach nourishment or coastal restoration. These zones may be protected from conflicting activities and are often defined by federal or state sediment resource programs. In addition to the resource implications, these areas may be susceptible to significant morphological changes. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material.
   Sand ridges	(MOBBED) Elongated sand bodies that are larger and geographically more stable than dunes or sand waves. These are large-scale features which far exceed the scale of sand wave bedforms and are not typically defined by specific height or wavelength parameters. They often appear as shore-oblique or shore-parallel features with a ridge-and-swale morphology. These features may reflect past depositional regimes and are often considered quasi-stable or relict, but their form is attributed to wave- and current-driven sediment transport. Sand ridges may occur independently or in association with smaller-scale bedforms (e.g., sand waves, ripples). Interpretations may reflect the presence, type, geometry, and distribution of bedforms; evidence of migration or orientation; and indicators of sediment transport and supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or sediment thickness conducive to bedform development.
   Sand waves	(MOBBED)Large-scale bedforms typically exceeding 60 meters in wavelength and 1.5 meters in height, however, this classification may also apply to sand-wave-like features described in source material that lack defined geometry. While often associated with active sediment transport, features may also represent relict (non-mobile) forms preserved from past depositional conditions. Sand waves may occur in isolation or as part of bedform complexes (e.g., ripples, megaripples). Interpretations may reflect the presence, type, geometry, and distribution of bedforms; evidence of migration or orientation; and indicators of sediment transport and supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or sediment thickness conducive to ripple formation.
   Shallow bedrock	(HARDBOT) Refers to features characterized by consolidated, semi-consolidated, or otherwise hard substrate buried by younger sediments that resides within tens of meters of the sea floor.
   Shallow gas or gas seeps	(GAS) Refers to the gas trapped in shallow sediments that can be derived from biogenic activities or seeping upwards from a deeper gas reservoir source. Shallow gas or gas seeps can be inferred from acoustic blanking, gas chimneys, or water column anomalies identified in seismic reflection and sonar data. Indications of gas may also be identified from geotechnical sampling.
   Shipwrecks	(ANTHR) Remnants of a ship once it has sunk to the sea floor. These features are typically derived from sonar imagery, magnetometer data, or public inventories. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material.
   Slides	(SLOPE) Refers to a mass movement where slide material is separated from more stable underlying material. Slides are identified as areas of mass movement where distinct blocks of sediments have been displaced along shear failure surfaces. Sonar data may identify morphological indicators of sliding and seismic reflection profiling may resolve disturbed stratigraphy. Both sources of data may be used to infer the age of sliding, its extent, and the potential for future instability.
   Slumps	(SLOPE) Refers to a coherent mass of loosely consolidated material that moved down a slope. Slumps are identified as areas of rotational mass movement and deformation. Sonar data may identify morphological indicators of slumping and seismic reflection profiling may resolve deformed stratigraphy and concave upward reflectors. Both sources may be used to infer the age of slumping, its extent, and the potential for future instability.
   Steep slopes	(SLOPE) A slope of 10 degrees or greater. However, this class may also include features or areas described as steep or potentially unstable without explicit slope measurements. Interpretations may indicate sea-floor morphology, adjacent geomorphic features (e.g., scarps, bedform faces), or areas inferred to have higher mass movement or erosional risk. Descriptions may vary depending on data resolution and whether slope instability is actively assessed.
   Subsurface boulders	(HARDBOT) This class identifies buried features interpreted as boulders located beneath the sea-floor surface, typically within glacial or para-glacial sedimentary units. These features may pose hazards to foundation and cable installation. Interpretations are derived from seismic reflection data. As with surface boulders, this classification is limited by the resolution and penetration of available data and is not based on strict grain-size definitions. Subsurface boulders are often inferred in areas underlain by till, moraine, or other heterogeneous glacial deposits.
   Subsurface deformation	(SUBSURF) Refers to disrupted stratigraphy that has undergone deformation due mechanisms such as folding, shearing, and thrusting. These features are identified in seismic reflection profiles as warped reflectors, however they may not correspond to discrete fault planes. Many deformational features are glaciotectonic in origin, formed by ice loading or thrusting.
   Surface boulders	(HARDBOT) This class identifies isolated or clustered features interpreted as boulders present at or near the sea floor surface. Classification is based primarily on data such as sonar, bathymetry, and backscatter. The ability to resolve individual boulder features is constrained by the resolution of the dataset. Consequently, this classification is not tied to a strict grain-size threshold. Instead, it includes clastic features that are visibly distinct in geophysical data and interpreted as potential obstructions. Boulders may occur as isolated features or within mapped boulder fields and are often associated with glacial deposits or coarse lag surfaces.
   Unclassified bedforms	(MOBBED) Any bedforms that are not classified as ripples, megaripples, sand waves or sand ridges. Unclassified bedforms are used where the term “bedform” is mentioned in source material without clear attribution to a specific type. This classification also applies when features are noted based on acoustic signature or generalized morphology but lack sufficient resolution or description to assign to a defined category. It may reflect uncertainty in scale, geometry, or process interpretation. Interpretations may reflect the presence, type, geometry, and distribution of bedforms; evidence of migration or orientation; and indicators of sediment transport and supply. Interpretations may also incorporate observations of active scour, zones of high mobility, or sediment thickness conducive to bedform development.
   UXO/MEC	(ANTHR) Identifies known or interpreted unexploded ordnance (UXO) or munitions of explosive concern (MEC) on or near the seafloor. These features are typically derived from sonar imagery, magnetometer data, or public inventories. Mitigation measures such as avoidance buffers or additional investigations may be specified by the source material.

   NOTE

   Free-text field containing source-specific notes or interpretation details related to the classification in the IDEN attribute. May or may not be present for all values of the IDEN attribute (Y, N, NA). (Source: Producer defined.) text

   SRC

   Identifies the data sources used to populate the NOTE field. Source information may include document titles, sections, figures, tables, or other reference points. Where multiple sources are presented, they are separated by a semi-colon ';'. (Source: Producer defined.) text. NULL values occur when no source was identified to identify or exclude a particular hazard.

   LINK

   URL to the source identified in the SRC attribute. If there are multiple sources, then the URL's are in the same order as the sources are presented, separated by a semi-colon ';'. In the event that multiple sources use a single link, only one link is provided. All URL's for sources were valid at the time of the work, but support for these web resources may change overtime. (Source: Producer defined.) Text. NULL values occur when no source is identified in the SRC attribute.

   ACCESSED

   The most recent date in the format MM/DD/YYYY (in the database as YYYY-MM-DD) that the source was accessed for the information used in the dataset. NULL values occur when no source is identified in the SRC attribute. (Source: Producer defined.) Text. NULL values occur when no source is identified in the SRC attribute.

   IDEN

   Indicates whether a geohazard was positively identified, explicitly ruled out, or not described in the source material. (Source: Producer defined.)

   Value	Definition
   NA	Not referenced or assessed in the source material, or no sufficient interpretation available.
   N	Explicitly confirmed absent within the area of interest, to the extent permitted by the resolution, coverage, and quality of available data.
   Y	Positively identified or inferred from supporting evidence in the source material.

   UNID

   Unique identifier for the record in the format 'O' plus UNID_P value plus a 4-digit number. (Source: Producer defined.) formatted text

   UNID_P

   ID for the record that is the identifier of the related feature in OI polygon table in the format 'O' plus a unique number ranging from 1001 to 1054 where the number is equal to the OBJECTID of the related polygon record. This value can repeat in this table and is used to provide a one-to-many relationship between the OI_GHZD_Polygons dataset and the OI_GHZD_Table dataset. (Source: Producer defined.) formatted text

   Entity_and_Attribute_Overview:

   The GeoPackage format does not support a one-to-many join like that of the ArcGIS Geodatabase format. However, there are software packages which support SQL views, which are effectively the same thing. These software packages include QGIS, Global Mapper, etc. therefore the GeoPackage also includes OI_GHZXD_Join_View. This view has 1836 records corresponding to the number of records in the OI_GHZD table with attributes that correspond to that table with the additional of a Geometry attribute to contain the spatial information of the polygon. The attributes and their definitions are as follows:
   OBJECTID: Unique value corresponding to the record within the dataset. May or may not be visible depending on the software package used to view the data.
   LEASE_NUMB: Lease number assigned to the polygon according to their BOEM designation, with the exception of records starting with NYS, which are text only and refer to the NYSERDA source. Alphanumeric values beginning with OCS are source from BOEM - Outer Continental Shelf lease block.
   GHZD: Geohazard classification representing the type of geological or geotechnical hazard identified within a given spatial domain.
   NOTE: Free-text field containing source-specific notes or interpretation details related to the classification in the IDEN attribute. May or may not be present for all values of the IDEN attribute (Y, N, NA).
   SRC: Identifies the data sources used to populate the NOTE field. Source information may include document titles, sections, figures, tables, or other reference points. Where multiple sources are presented, they are separated by a semi-colon ';'.
   LINK: URL to the source identified in the SRC attribute. If there are multiple sources, then the URL's are in the same order as the sources are presented in the corresponding note, separated by a semi-colon ';'. In the event that multiple sources use a single link, only one link is provided. All URL's for sources were valid at the time of the work, but support for these web resources may change overtime.
   ACCESSED: The most recent date in the format MM/DD/YYYY (in the database as YYYY-MM-DD) that the source was accessed for the information used in the dataset. Blank values occur when no source is identified in the SRC attribute.
   IDEN: Indicates whether a geohazard was positively identified, explicitly ruled out, or not described in the source material.
   UNID: Unique identifier for the record in the format 'OI' plus UNID_P numerical value plus a 4-digit number.
   UNID_P: ID for the record that is the identifier of the related feature in OI polygon table in the format 'OI' plus a unique number ranging from 001 to 054 where the number is equal to the OBJECTID of the related polygon record. This value can repeat in this table and is used to provide a one-to-many relationship between the OI_GHZD_Polygons dataset and the OI_GHZD_Table dataset.
   GEOMETRY: Attribute used to store the geometry of the record. May or may not be visible depending on the software package used to view the data.

   Entity_and_Attribute_Detail_Citation: Data release authors - Brian Curran and Laura Brothers.
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Brian J. Curran
   • Laura L. Brothers
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey

   Attn: Laura L. Brothers

   Research Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 x2312 (voice)

   lbrothers@usgs.gov

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: 2025 (process 1 of 15)

   This data release effectively releases two datasets as part of the GeoPackage. One is referred to as the OI dataset which refers to Offshore Infrastructure (OI). This dataset is comprised of non-proprietary information available from documents submitted by Offshore Wind Developers as part of the permitting process. The OI dataset itself is comprised of two components: a vector feature class (OI_GHZD_Polygons) representing active lease areas, investigation areas, and export cable corridors; and a non-spatial table (OI_GHZD_Table) containing geohazard classifications and descriptions derived from developer-submitted documents. There is a one-to-many relationship between the polygon feature class and the table information. The attribute UNID_P, present in both datasets is used to relate the information presented in a join view (OI_GHZD_Join_View) in the GeoPackage. The second dataset is referred to as the TD dataset which refers to Trusted Datasets (TD). This dataset represents all the other studies examined as part of this work that are publicly available. This availability includes a wide range of publications and information available online. The TD dataset (TD_GHZD_FC) is a single feature class within the GeoPackage. These two datasets (OI and TD) will be described in two paths of processing for the initial work, then the work is combined into a single database and processing occurring on that package. The initial work with regards to both datasets was in ArcGIS Pro (v. 3.2) file geodatabases with the work on each dataset initially done in separate geodatabases. Eventually, for release purposes, the two datasets were merged into a single GeoPackage. The first process steps will address the work on the OI dataset, followed by the TD work, and finally the joint work. This work was an iterative process that started in September 2023 and finished in April 2025. The processing date is the latest process date for when the project was completed.
   Because the nature of the work involves accessing information from sources, and the sources are included as part of the dataset, the metadata source contributions will not be used. However, when a citation is indicated in a process step, that process step will include the citation as the end of the process step in addition to a cross-reference listing. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Brian Curran

   USGS Contractor

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 (voice)

   whsc_data_contact@usgs.gov

   Contact_Instructions:

   The contact email address is a generic address since this person is no longer with the USGS.

   Date: Apr-2025 (process 2 of 15)

   OI dataset overview:
   Offshore Infrastructure (OI) data were compiled as part of a systematic inventory of non-proprietary, publicly available site characterization documents related to offshore renewable energy development. Selection criteria were limited to projects within active Bureau of Ocean Energy Management (BOEM) lease areas that had published developer-submitted data relevant to geohazard identification. These data were retrieved primarily from Site Assessment Plans (SAPs), Construction and Operations Plans (COPs), and ancillary planning materials available on boem.gov/renewable-energy, as well as from other official sources such as the New York State Energy Research and Development Authority (NYSERDA) via nyserda.ny.gov and nyserdageosurvey.wspis.com, however at the time of this publication the NYSERDA data portal was no longer active. Source material was accessed and reviewed for data which characterized geohazards within a given domain. The NOTES field was populated with the relevant hazard characterization and the IDEN field was populated to indicate a positive (Y) or negative (N) identification of the given hazard. Where insufficient characterization material existed, IDEN was populated with 'NA'. Data sources varied in format, and included results from text interpretations, figures, and tables. Polygon shapefiles were created to assign geospatial domains to individual project components. This work is described in more detail in subsequent process steps. Project components refer to SAP Survey Areas or Areas of Potential Effect (APE), lease sites, and export cable corridors associated with an individual project. Geospatial data constraining these project components were created using a range of publicly available sources. All the work was performed by Brian Curran until otherwise noted. The process step took place over a time period of September 2023 to April 2025. The process date represents the most recent completion of the work. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Brian Curran

   USGS Contractor

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 (voice)

   whsc_data_contact@usgs.gov

   Contact_Instructions:

   The contact email address is a generic address since this person is no longer with the USGS.

   Date: Jan-2025 (process 3 of 15)

   OI SAP Survey Areas or APEs:
   The geometry was created using point data of fixed-position components such as meteorological buoys or towers. Coordinates were retrieved from the source material specified in the SRC field. This process step is captured in the DOMAIN_M field by the code 'DC'. These points represent the site of the installed component which is the subject of the SAP. It is not necessarily coincident with the centroid of the SAP survey area or APE as the offset, scale, and geometry of these areas can vary considerably between sites. The original source material should be referenced for exact boundaries.
   Input coordinates were provided in a mix of UTM Zone 18N/19N (NAD 1983), GCS WGS 1984, and unspecified coordinate systems. In ArcGIS Pro (v. 3.2), multipoint feature classes were created from scratch within a GeoDatabase using their native (or assumed, described later) coordinate systems. These feature classes were then exported and reprojected to GCS WGS 1984, with datum transformations automatically applied by the software using the default transformation of the software where necessary. For coordinates with an unknown coordinate system, assumptions were made based on contextual information such as year of data collection and numeric format of the coordinates. BOEM regulates that all submitted electronic files are to be referenced to NAD 83, however this may differ from how the information is depicted in figures. All data are assumed to be in accordance with BOEM's expectations of current and accurate data. Minor positional shifts may have occurred due to differences between NAD 1983 and WGS 1984. Specific transformation methods applied by ArcGIS Pro (v. 3.2) were not recorded. After standardization, the polygons were merged into a single feature layer. To approximate the SAP Survey Area or APE boundaries, a 1 km buffer was applied to the merged multipoint feature class, creating a polygon feature class. Buffering is captured in the DOMAIN_M field by the code 'B'. The process step took place over a time period of January 2024 to January 2025. The process date represents the most recent completion of the work.

   Date: Apr-2024 (process 4 of 15)

   OI Lease Sites:
   The geometry for OI lease sites was created using several sources. Offshore wind lease polygons were retrieved from the 'Offshore Wind Lease Outlines' feature class available on Marine Cadastre (https://hub.marinecadastre.gov/datasets/BOEM::offshore-wind-lease-outlines/about) version updated on 16th November 2023 in geodatabase feature class format. This geodatabase feature class was accessed on 20240108. All geometry was imported into an ArcGIS Pro (v. 3.2) GeoDatabase as a feature class in the native coordinate system of the original dataset of GCS WGS 1984.
   In several instances, lease site geometries retrieved from the Marine Cadastre dataset were modified to reflect alternative boundaries depicted in the developer documents source material. To ensure accuracy, figures from developer documents were captured in JPEG format, imported to ArcGIS Pro (v. 3.2), and georeferenced using the Georeferencing toolset in ArcGIS Pro (v 3.2). If georeferencing was necessary, that is captured in the DOMAIN_M field by the code 'GF'. Control points were placed on identifiable reference features, such as lease block corners or coastline markers, ensuring the images were referenced to known features. A first-order polynomial (affine) transformation was applied in most cases to maintain linearity, though higher-order transformations were used where necessary to correct distortions. The georeferenced images were then overlayed with the original Marine Cadastre polygons, which were manually adjusted using the Edit Vertices tool within the Modify Features pane. Manual adjustments are captured in the DOMAIN_M field by the code 'MA'.
   In several instances, modifications conformed to the boundaries of the BOEM OCS Block 1/16 Aliquot Parts shapefile (https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data), which was reprojected on-the-fly from NAD83 (EPSG: 4269) to GCS WGS 1984 (EPSG: 4326) by ArcGIS Pro (v. 3.2). Domains created using vector boundaries are captured in the DOMAIN-M filed by the code 'VBD'. All the work was performed by Brian Curran until otherwise noted. The process step took place over a time period of January 2024 to April 2024. The process date represents the most recent completion of the work.
   References:
   Bureau of Ocean Energy Management, 2023, Marine Cadastre - Offshore Wind Lease Outlines (version updated on 16th November 2023: https://hub.marinecadastre.gov/datasets/BOEM::offshore-wind-lease-outlines/about. Accessed on January 8, 2024.
   Bureau of Ocean Energy Management, 2012, Atlantic Cadastral Data - BOEM OCS Block 1/16 Aliquot Parts shapefile (version updated on 11/2/2012): https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data. Accessed on December 12, 2024.

   Date: Mar-2024 (process 5 of 15)

   OI NYSERDA:
   The geometry for the Hudson North (A and B) and Hudson South study areas within the New York Bight region was created by georeferencing JPEG images derived from the site characterization reports included in the 2019 NYSERDA submission. These images were aligned to known spatial reference using the BOEM OCS Block 1/16 Aliquot Parts shapefile (https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data), which was reprojected on-the-fly from NAD83 to GCS WGS 1984 in ArcGIS Pro (v. 3.2). Using the Georeferencing toolset, control points were placed on identifiable aliquot block corners. Georeferencing using vector boundaries is captured in the DOMAIN_M field by the codes 'GF' and 'VBD'. Polygons for the study areas were then digitized from scratch using the Create Features and Edit Vertices tools and saved to a GeoDatabase feature class in GCS WGS 1984.
   The NYSERDA Approach Areas — namely, the New York Harbor Approach Area, Long Island Sound Approach Area, and South Shore Approach Area — were digitized from Figure 1 ('Study Area and Approach Areas') of the NYSERDA Corridor Study report. As geospatial data for these boundaries was not publicly released, the resulting features represent georeferenced approximations based on the visual depiction in Figure 1 in the report. The georeferencing process was performed using the Georeferencing tools in ArcGIS Pro (v. 3.2), and alignment was guided by shoreline features derived from the National Oceanic and Atmospheric Administration's (NOAA) Coastal Counties and Federal and State Waters geodatabase datasets (https://catalog.data.gov/dataset/federal-and-state-waters5/resource/52ce8fc2-7085-49d8-917e-bf9a9456aeb1). Georeferencing using vector boundaries is captured in the DOMAIN-M field by the codes 'GF' and 'VBD'.
   Where applicable, the 'Coastal County' geodatabase feature class retrieved from Marine Cadastre (https://hub.marinecadastre.gov/datasets/noaa::coastal-counties/about) was used to approximate the terrestrial boundary of each Approach Area. Seaward boundaries were digitized directly from the georeferenced image, where they were clearly distinguishable. Due to the relatively coarse resolution of the original figure, small water features such as inlets, estuaries, and rivers were not consistently represented and were clipped from the final features using the Edit Vertices tool within the Modify Features pane and the Erase tool. All approach area feature classes were created from scratch in GCS WGS 1984 to maintain consistency with the larger geodatabase. The WGS 84 is accounted for during the georeferencing process where the features used for the georeferencing were WGS 84. The process step took place over a time period of February 2024 to March 2024. The process date represents the most recent completion of the work.
   References:
   National Oceanic and Atmospheric Administration, Marine Cadastre - Coastal Counties: https://hub.marinecadastre.gov/datasets/noaa::coastal-counties/about. Accessed on September 11, 2023.
   National Oceanic and Atmospheric Administration, Marine Cadastre – Federal and State Waters: https://catalog.data.gov/dataset/federal-and-state-waters5/resource/52ce8fc2-7085-49d8-917e-bf9a9456aeb1. Accessed on September 11th, 2023.

   Date: Jan-2025 (process 6 of 15)

   OI Export Cable Corridors:
   Export Cable Corridor (ECC) features were derived primarily from the 'Offshore Wind - Export Cable Corridors (Proposed)' feature layer hosted on Marine Cadastre, version December 21, 2023, GCS WGS 1984. These data represent proposed cable corridor boundaries submitted by lessees during various phases of project development. No modifications were made to these features except where noted.
   In cases where multiple cable corridors diverged from a central route, features were dissolved using the Dissolve tool to create a single boundary representing the full extent of potential ECCs. Where two or more distinct corridors persisted throughout their routes, features were maintained as separate components (polygons) within the dataset.
   For the Virginia Offshore Wind Technology Advancement Project (VOWTAP), cable corridor geometry was derived from the 'Submarine Cable Areas' feature layer on Marine Cadastre, version May 1, 2023, GCS NAD83. These data represent installed submarine cable rights-of-way and were used as an approximation of the VOWTAP export corridor due to the absence of a public version of the 300-meter survey corridor referenced in the project's site characterization report.
   Some native ECC features are truncated at the federal-state 3 nautical mile jurisdiction boundary. These were retained where no more recent data was available. No georeferencing or vector modifications were performed for ECCs. All features were imported into a GeoDatabase within ArcGIS Pro (v. 3.2) using their native coordinate system and reprojected to GCS WGS 1984 for consistency across the geodatabase. The process step took place over a time period of January 2024 to January 2025. The process date represents the most recent completion of the work.

   Date: 2025 (process 7 of 15)

   TD dataset:
   An inventory was conducted to identify publicly available geophysical and geological studies relevant to sea-floor geohazards along the U.S. Atlantic and Pacific margins. Geohazard data were extracted from publicly available geological mapping studies, site investigation reports, and regional assessments authored by the U.S. Geological Survey, state geological surveys, and academic institutions. Source material spans publication years from 1972 to 2024 and was accessed through a range of official and scholarly repositories, including pubs.usgs.gov, ngmdb.usgs.gov, cmgds.marine.usgs.gov, boem.gov, digitalmaine.com, dgs.udel.edu, and research databases such as ScienceDirect, GeoScienceWorld, and AGU publications. Source material was accessed and reviewed for data which characterized geohazards. All links for cited references and data portals were valid at the time of the work, but support for these web resources may change overtime.
   Hazards were categorized according to seven classifier types: mobile bedforms, hardbottom, sediment properties, slope properties, gas, structural features, and anthropogenic features. For each classifier, a pair of fields was used: a presence/absence indicator (e.g., MOBBED, HARDBOT, SED, etc.) and an associated notes field (e.g., MOBBED_N, HARD_N, SED_N, etc.). The indicator fields record whether the hazard is present ('Y'), or not applicable ('NA'), while the corresponding notes fields provide supporting descriptions or interpretations derived from the source material where a 'Y' is present in the indicator field. Source material varied in format and included geophysical maps, descriptive text, interpretive models, and tabular data. The process step took place over a time period of September 2023 to 2025. The process date represents the most recent completion of the work.

   Date: 2025 (process 8 of 15)

   TD dataset criteria:
   Sources were included if they documented original or reinterpreted geophysical data (e.g., seismic reflection, sidescan sonar, and bathymetry) associated with marine geological studies or hydrographic surveys. Sources were required to present spatially resolved interpretations that significantly contribute to an assessment of hazards—such as maps, figures, or cross-sections—and not consist solely of derived products unaccompanied by interpretation, except bathymetry which is discussed later in this process step. Standalone 1D or discrete geophysical datasets (e.g., grain-size grabs or sediment cores lacking spatial interpretation) were also excluded. The exception to this is 90 CAPE HATTERAS piston core analyses, Gulf of Maine, U.S.A. and Nova Scotia, Canada. This dataset was included for its ID of shallow gas-bearing muds, which is a finding that significantly contributes to an understanding of the geohazards within its study domain. Some sources which solely rely on previously published data were retained if they significantly contributed to the evaluation of geohazards on the shelf by synthesizing disparate sources and contributing meaningful reinterpretations.
   Vector data derived from native sources (i.e., habitat polygons, soil provinces) were used to create study domains. Domains which were derived from altered vector data are captures in the DOMAIN-M field by the codes 'NAT' and 'V'.
   Bathymetric datasets were included even when unaccompanied by explicit interpretations, as they provide spatially continuous morphological context that can be readily reinterpreted to evaluate several hazard types. The usage of the native raster data is captured in the DOMAIN_M field by the codes 'NAT' and 'R'. These products support the identification of steep gradients such as escarpments, sand ridges, shelf-edge features, and bedforms which may significantly contribute to hazard assessments, especially in areas where geophysical data coverage may be otherwise lacking.
   In selecting sources, preference was given to newer or higher-resolution datasets when they provided clearer interpretations or more detailed observations, which in certain instances justified exclusion of older or overlapping sources. Sources were also excluded if the quality or reliability of the data were uncertain—regardless of whether alternative coverage existed—particularly when methodological documentation was lacking, or interpretive conclusions could not be independently validated.
   Certain lower-resolution datasets were retained due to their extensive spatial coverage. Despite their lower resolution, these datasets were valuable for contextualizing geohazard trends at broader scales and infilling spatial gaps between higher-resolution surveys. The process step took place over a time period of September 2023 to 2025. The process date represents the most recent completion of the work.

   Date: Mar-2025 (process 9 of 15)

   TD dataset - Establishing a General Domain:
   Spatial domains were created to define the geographic extent of each study used in the geohazard inventory. Source material varied in format and spatial detail, requiring a range of processing methods to ensure consistency across the dataset. All geometry processing was performed in ArcGIS Pro (v. 3.2) within a standardized geodatabase environment, and all features were exported from their native coordinates systems to the Geographic Coordinate System (GCS) WGS 1984.
   Publicly available geospatial data were used to define domain boundaries, either in whole or in part. These sources included study-specific polygons, boundary datasets from public repositories, and vector or raster data from formal data releases. In some instances, geometries were duplicated and repurposed for subsequent entries which contributed new material or expanded on previous interpretations. It was rare for study domains to be exactly the same, however for completeness all were includes with a separate record for each source. The schema for the database is one entry per source. Multiple sources might refer to a particular area but identify different hazards.
   For sources that lacked native geospatial formats but included spatial representations in the form of maps, diagrams, or figures, JPEG images were captured and treated as unreferenced images within a GCS WGS 1984 workspace in ArcGIS Pro (v. 3.2). Because coordinate system information was generally not stated in the source material, no projection metadata were recorded during processing. The images were georeferenced using the Georeferencing toolset, with control points placed on identifiable spatial features (e.g., graticule ticks, coastlines, lease block corners) to anchor them to real-world coordinates. A first-order polynomial (affine) transformation was applied in most cases to preserve linearity, while higher-order transformations were used when necessary to correct visual distortion. Study domain boundaries were then digitized manually on top of the georeferenced image using the Create Features and Edit Vertices tools within the Modify Features pane. Georeferencing and manual editing are captured in the DOMAIN_M field by the codes 'GF' and 'MA'.
   In several instances, entries were digitized according to the boundaries of the BOEM OCS Block 1/16 Aliquot Parts shapefile (https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data), which was reprojected on-the-fly from NAD83 to GCS WGS 1984 by ArcGIS Pro.
   For sources that included native raster or vector datasets, versions in GCS WGS 1984 were used whenever available. If native datasets were in a different coordinate system, they were exported and standardized to GCS WGS 1984 using the default transformation settings of ArcGIS Pro. Specific transformation methods applied by ArcGIS Pro were not recorded. The process step took place over a time period of November 2024 to March 2025. The process date represents the most recent completion of the work.
   Reference:
   Bureau of Ocean Energy Management, Atlantic Cadastral Data - BOEM OCS Block 1/16 Aliquot Parts shapefile: https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data. Accessed on December 12, 2024.

   Date: Mar-2025 (process 10 of 15)

   TD dataset - Domain Refinement:
   Geoprocessing steps were applied as needed to finalize the geometry of each study domain. This included manual adjustments to align with known boundaries and simplification operations to generalize complex geometries. In cases where study areas were not explicitly defined—such as points and line-based features or figures with indeterminate study domains—envelopes or simplified bounding geometries were created using the Minimum Bounding Geometry tool to approximate the spatial domain. This was necessary in areas where there might be a crude cluster of points with no confining boundaries but for the purpose of this work an approximate study area polygon is necessary.
   For raster-based sources with complex boundaries, a standardized set of geoprocessing steps was applied to all entries to reduce geometric complexity and generate consistent domain boundaries. Raster surfaces were first converted to polygon features using the Raster Domain tool in the 3D Analyst toolbox of ArcGIS Pro (v. 3.2). Eliminate Polygon Part was applied to remove interior gaps smaller than 20 percent of the total feature area. A uniform buffer was then applied to all complex domains to generalize their extent and eliminate edge artifacts. Finally, a combination of manual editing with the Modify Features pane, Simplify Polygon, and Smooth Polygon were used to reduce vertex density and improve polygon appearance. Feature simplification is captured in the DOMAIN_M field by the code 'SG'. The process step took place over a time period of November 2024 to March 2025. The process date represents the most recent completion of the work.

   Date: 2025 (process 11 of 15)

   Final processing within the ArcGIS Pro environment involved exporting all geodatabase feature classes into their respective GeoPackage feature classes under a single GeoPackage (.gpkg) format for publication. In ArcGIS Pro (v. 3.2) the tool GeoPackage (create a new GeoPackage) was used to create the empty GeoPackage v. 1.0 in accordance with the standard version endorsed by FGDC (https://www.fgdc.gov/standards/FGDCendorsesFiveStandards). Once the GeoPackage was created, the feature classes from the ArcGIS Pro (v. 3.2) file geodatabase could be exported to that GeoPackage using the 'Data - Export Features' available from the right-mouse click of the feature class. Following export, the GeoPackage was manually inspected for formatting issues, including errant or non-standard characters in attribute fields, incomplete field entries, and unexpected values. Final quality control included a review of attribute domains, geometry validity checks, and confirmation that all expected features were successfully transferred to the GeoPackage format. The final process was completed in 2025 after iterations and corrections to the work.
   Reference:
   Federal Geographic Data Committee, FGDC endorses five standards: https://www.fgdc.gov/standards/FGDCendorsesFiveStandards, last accessed April 2025.

   Date: Mar-2025 (process 12 of 15)

   For the OI Dataset, an SQL-based virtual table – referred to as a 'view' – was initially created within the GeoPackage using the software DB Browser for SQLite Windows PortableApp (version 3.1.2.2) to relate the spatial feature class 'OI_GHZD_Polygons' with the standalone table 'OI_GHZD_Table'. This view, titled 'OI_GHZD_Join_View', links the two items using the shared 'UNID_P' attribute. This relationship reflects a one-to-many structure: each polygon may be associated with multiple geohazard records in the table. This method allows users to visualize and query multiple geohazard records per spatial feature without duplicating their geometry. The process date represents the initial view creation.

   Date: May-2025 (process 13 of 15)

   During the final dataset verification and clean-up, all work was performed on the GeoPackage. For the TD dataset, the final edits to attribute values were completed using QGIS v. 3.40.6. Any additional edits to the OI Table were performed using Navicat Premium database management software (v. 16). Two SQL scripts needed to be run to finalize the tables. The first is to create the UNID (the unique identifier) for each row of the OI_GHZD table. This identifier is based on a combination of the UNID_P and unique sequential row number within the table (OBJECTID). The SQL command to perform this function is:
   UPDATE OI_GHZD_Table SET UNID = UNID_P || CASE WHEN OBJECTID < 10 THEN '000' || OBJECTID WHEN OBJECTID < 100 THEN '00' || OBJECTID WHEN OBJECTID < 1000 THEN '0' || OBJECTID ELSE OBJECTID END;
   The other SQL script that needed to be run was to recreate the view which effectively mimics a one-to-many join. The SQL script for this is:
   DROP VIEW IF EXISTS OI_GHZD_Join_View;
   CREATE VIEW OI_GHZD_Join_View AS SELECT OI_GHZD_Polygons.Shape, -- Geometry (MULTIPOLYGON) OI_GHZD_Table.OBJECTID AS TABLE_OID, -- Object ID from non-spatial table (aliased) OI_GHZD_Table.LEASE_NUMB, OI_GHZD_Table.GHZD, OI_GHZD_Table.NOTE, OI_GHZD_Table.SRC, OI_GHZD_Table.LINK, OI_GHZD_Table.ACCESSED, OI_GHZD_Table.IDEN, OI_GHZD_Table.UNID, OI_GHZD_Polygons.UNID_P -- join key FROM OI_GHZD_Polygons LEFT JOIN OI_GHZD_Table ON OI_GHZD_Polygons.UNID_P = OI_GHZD_Table.UNID_P;
   This process step and the following process step were performed by the same person, VeeAnn A. Cross. The process date represents the most recent completion of the work. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 x2251 (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 the USGS.

   Date: May-2025 (process 14 of 15)

   The final work associated with the dataset was to create symbology files. Since the GeoPackage can be viewed in both ArcGIS Pro and QGIS, both LYRX (ArcGIS Pro) and qlr (QGIS) symbology files were created. This is a difficult dataset to present visually, however these symbology files are a starting point. Individual users will probably need to apply their own symbology based on their interests. The symbology files for the OI data are in the folder OI while the symbology files for the TD feature class are in the TD folder. ArcGIS Pro (version 3.4.3) and QGIS (v. 3.40.6) were used to create the symbology files.
   OI dataset: For the OI dataset, there are seven symbology files compatible with ArcGIS Pro (*.lyrx files). This symbology probably does not show much distinction due to the combining of the classifications. However, it is provided as an option for viewing the data.
   These files symbolize the OI dataset based on the seven classification groups that encompass the 34 individual hazard classifications. These classification groups are ANTHR (OI_ANTHR.lyrx), GAS (OI_GAS.lyrx), HARDBOT (OI_HARDBOT.lyrx), SLOPE (OI_SLOPE. lyrx), MOBBED (OI_MOBBED.lyrx), STRUCT (OI_STRUCT.lyrx) and SUBSURF (OI_SUBSURF.lyrx). Each of these 7 symbology files uses a definition query to select only the more specific geohazard classifications that are included in each of the larger classifications and displays those values with a definitive ('Y' or 'N') identification of occurrence. The SQL definition queries are as follows:
   OI_ANTHR.lyrx: (GHZD = 'Shipwrecks' Or GHZD = 'UXO/MEC' Or GHZD = 'Cables' Or GHZD = 'Pipelines' Or GHZD = 'Anchorages, dumping grounds, disposal sites' Or GHZD = 'Sand resource areas' Or GHZD = 'Other seabed obstructions') And (IDEN = 'Y' Or IDEN = 'N')
   OI_GAS.lyrx: (GHZD = 'Shallow gas or gas seeps' Or GHZD = 'Pockmarks' Or GHZD = 'Gas hydrates') And (IDEN = 'Y' Or IDEN = 'N')
   OI_HARDBOT.lyrx: (GHZD = 'Glacial till' Or GHZD = 'Moraines' Or GHZD = 'Outcrops, reefs, or exposed rocky areas' Or GHZD = 'Shallow bedrock' Or GHZD = 'Subsurface boulders' Or GHZD = 'Surface boulders') And (IDEN = 'Y' Or IDEN = 'N')
   OI_MOBBED.lyrx: (GHZD = 'Areas prone to scour' Or GHZD = 'Bedform migration' Or GHZD = 'Megaripples' Or GHZD = 'Ripples' Or GHZD = 'Sand ridges' Or GHZD = 'Sand waves' Or GHZD = 'Unclassified bedforms') And (IDEN = 'Y' Or IDEN = 'N')
   OI_SLOPE.lyrx: (GHZD = 'Mass transport scarps' Or GHZD = 'Slides' Or GHZD = 'Slumps' Or GHZD = 'Steep slopes') And (IDEN = 'Y' Or IDEN = 'N')
   OI_STRUCT.lyrx: (GHZD = 'Faults' Or GHZD = 'Fault scarps') And (IDEN = 'Y' Or IDEN = 'N')
   OI_SUBSURF.lyrx: (GHZD = 'Buried channels' Or GHZD = 'Glauconite' Or GHZD = 'Organic soil' Or GHZD = 'Peat' Or GHZD = 'Subsurface deformation') And (IDEN = 'Y' Or IDEN = 'N')
   TD dataset:
   The symbology for this dataset is for the definitive 'Y' for the unique seven identified geohazards: MOBBED (Mobile_Bedforms.lyrx), HARDBOT (Hard_Bottom.lyrx), SED (Sediment_challenge.lyrx), SLOPE (Slope_Properties.lyrx), GAS (Gas.lyrx), STRUCT (Structural.lyrx), and ANTH (Anthropogenic.lyrx)
   Those hazards defined what would be displayed, then symbology was chosen for each LYRX files in terms of polygon fill and color.
   Once the LYRX files were created, an attempt to create the QLR symbology in QGIS 3.40.6 using the plugin qlyrx version 0.3.5 was undertaken. Once the table of interest was loaded into QGIS and selected, the plugin was run and the appropriate LYRX was selected. Once the symbology was applied to the layer, the layer name was adjusted and the symbology saved as a QLR file by right-clicking on the layer and Export - Save as layer definition file. The QLR files contains the layer source plus the style information. Unfortunately, the definition query used for the LYRX for the OI dataset also had to be applied in QGIS from under the Properties - Source menu option for those layers due to the complicated nature of the GeoPackage View and that specification not coming across. Although a definition query was not required for the simpler TD layers in QGIS, one was also applied. In some cases, the symbology imported with a fill, whereas none of the LYRX symbology had fills, so those were attended to as well.
   For the OI dataset, the QLR files are: oi_anthr.qlr, oi_gas.glr, oi_hardbot.qlr, oi_mobbed.qlr, oi_slope.qlr, oi_struct.qlr, oi_subsurf.qlr.
   For the TD datasets, the QLR files are anthropogenic.qlr, gas.qlr, hardbottom.qlr, mobile_bedforms.qlr, sed_challenge.qlr, slope_properties.qlr, structural.qlr.
   The use of the symbology layers requires a specific folder structure. The OI symbology (within the OI folder) and the TD symbology (in the TD folder) must be in folders below the GeoPackage.

   Date: 25-Sep-2025 (process 15 of 15)

   Minor fixes to the text were applied. This included some minor rewording of the abstract and a couple of grammatical edits in several other locations in the metadata.
   Additionally, the ReadMe.txt file was modified to reorganize the content and add additional examples of accessing the information in the GeoPackage. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   USA

   (508) 548-8700 x2251 (voice)

   (508) 457-2310 (FAX)

   vatnipp@usgs.gov

3. What similar or related data should the user be aware of?
   Bureau of Ocean Energy Management, 2023, Marine Cadastre - Offshore Wind Lease Outlines (version updated on 16th November 2023).

   Online Links:

   • https://hub.marinecadastre.gov/datasets/BOEM::offshore-wind-lease-outlines/about

   Other_Citation_Details:

   Resource for process steps and data, provides geospatial data of the outline version of offshore wind leases managed by the Bureau of Ocean Energy Management (BOEM). Numerous geospatial formats available.

   Bureau of Ocean Energy Management, 2012, Atlantic Cadastral Data - BOEM OCS Block 1/16 Aliquot Parts shapefile (version updated on 11/2/2012).

   Online Links:

   • https://www.boem.gov/oil-gas-energy/mapping-and-data/atlantic-cadastral-data

   Other_Citation_Details: Resource for process steps and data.
   

   National Oceanic and Atmospheric Administration, 20220613, Marine Cadastre - Coastal Counties (version accessed on 20230911).

   Online Links:

   • https://hub.marinecadastre.gov/datasets/noaa::coastal-counties/about

   Other_Citation_Details:

   Resource for process steps and data. Although the website lists the dataset as a shapefile, upon download it is a GeoPackage.

   National Oceanic and Atmospheric Administration, Marine Cadastre, 20180411, Federal and State Waters (version accessed on 20230911).

   Online Links:

   • https://catalog.data.gov/dataset/federal-and-state-waters5/resource/52ce8fc2-7085-49d8-917e-bf9a9456aeb1

   Other_Citation_Details: Resource for process steps and data.
   

   Federal Geographic Data Committee, Unknown, FGDC endorses five standards.

   Online Links:

   • https://www.fgdc.gov/standards/FGDCendorsesFiveStandards

   Other_Citation_Details:

   Resource used to select the software and version for releasing the data.

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?
   Spatial domains were generated using a variety of methods, and horizontal accuracy should be considered relative to both the source material and the processing steps documented in the DOMAIN_M attribute field.
   1. Sparsely Distributed Native Features (Vectors or Rasters):
   For studies with sparse spatial features (e.g., point samples, raster patches), domains were generalized using the Minimum Bounding Geometry tool in ArcGIS Pro. Employed geometry types included rectangle by area, rectangle by width, convex hull, and envelope. For smaller-scale domains, simplified shapes (e.g., envelopes) were used. In larger-scale domains, additional steps such as Buffer, Smooth Polygon, and Eliminate Polygon Part were applied to reduce extraneous space while minimizing geometric complexity. The largest buffer applied in this category was 10 km.
   These generalized boundaries represent the interpreted extent of study areas and may deviate from the true distribution of underlying features, which may be spaced tens to hundreds of kilometers apart. This bounding approach contrasts with multi-part study areas, which preserve discrete zones identified in the source material and whose individual parts should be considered independently for accuracy.
   2. Native Vectors or Rasters (Unmodified or Altered):
   Some domains were derived directly from native vector or raster datasets without modification. When reprojected from other coordinate systems into GCS WGS 1984, horizontal accuracy reflects any positional uncertainty introduced by the default ArcGIS datum transformation. In standard transformations such as NAD_1983 to WGS_1984, positional differences are typically on the order of 0 to 2 m. These discrepancies are considered negligible in the context of the larger dataset. Where no reprojection occurred, positional accuracy is assumed to match that of the original source.
   Other domains based on native vectors or rasters were modified slightly using tools such as Buffer or Simplify Polygon. For these, the minimum positional uncertainty corresponds to the buffer distance applied, plus the relatively minor transformation effects.
   Maximum buffer values included:
   SAP survey area approximations: 1 km
   Most general domains from native rasters/vectors: 0.5 km
   Other study domain generalizations: up to 2 km
   3. Georeferenced Domains from Non-Spatial Figures:
   Some domains were derived from non-geospatial images (e.g., figures in reports) that lacked explicit coordinate systems. These JPEGs were georeferenced using control points such as coastlines, lease block corners, and graticule ticks, then transformed using a first-order or greater polynomial. Work was conducted in GCS WGS 1984, and georeferencing residuals were maintained at or below 0.08 decimal degrees, with most residuals considerably lower.
   Digitized domains reflect either visible boundaries or approximated extents based on the figure context. These should be considered reasonable estimates of study area coverage, not precise outlines of hazard distribution.
   All domain creation methods are documented in the DOMAIN_M attribute field and described in the process steps of this metadata.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   OI:
   The Offshore Infrastructure (OI) dataset represents a non-exhaustive but systematic review of publicly available planning documentation associated with offshore renewable energy infrastructure. Only data that were accessible through BOEM, NYSERDA, and other official portals were included. Proprietary or redacted content was not available for review. At the time of publication the NYSERDA data portal was no longer active. The completeness of the OI dataset varies by project, component and is limited by the availability and interpretability of the source material. Domain boundaries were derived using a range of methods including buffering of point data, digitizing from georeferenced images, and direct use of published shapefiles. Spatial processing methods are documented in the attribute field DOMAIN_M. Classification fields were populated where hazards were explicitly discussed or strongly implied in the source material, while absence of sufficient characterization data was recorded as 'NA'. Where 'NA' was employed, the accompanying notes attribute was not populated.
   The spatial extent of the OI dataset is limited to lease sites, associated export cable corridors, and offshore wind-focused investigations, such as those led by NYSERDA. These features represent areas for which non-proprietary, interpretable information was publicly released as part of the planning or investigation process. The inclusion of an entry in the OI dataset is not determined by the current administrative status of a development area (e.g., planned, active, or inactive), but by the public availability of interpretable hazard-related information.
   Because the NYSERDA approach areas polygon is based on digitization of a low-resolution figure, the relative coarseness of that source meant that small water features such as inlets, estuaries, and rivers were not consistently represented. Some smaller-scale features, which may have been captured within reference material (i.e., Coastal Counties and Federal and State Waters) were excluded from the final product as they could not be resolved in the georeferenced image.
   Interpretable sources vary widely in format and structure, including narrative text, tables, maps, and figures. Many lack explicit spatial metadata or geospatial referencing, requiring manual interpretation of a spatial domain. Additionally, interpretable information was inconsistently presented in the source material, often shaped by the specific scope or technical focus of each document. Some documents omitted or did not address entire hazard categories or provided insufficient detail for inclusion. In these cases, records were marked 'NA' to indicate insufficient information, rather than absence of the hazard itself. Where hazards were sufficiently described, relevant content was distilled into notes fields that accompany each classification. These notes provide a summary of interpretations and supporting context and are intended to guide users but not replace the source documentation.
   TD:
   The Trusted Datasets (TD) dataset represents a curated inventory of publicly available geological and geophysical studies relevant to seafloor geohazards across the U.S. continental margin. The dataset includes over 175 studies spanning publication years from 1972 to 2024, which are drawn from federal agencies, state geological surveys, academic institutions, and recognized scientific repositories. Studies were selected based on the presence of spatially interpretable hazard information derived from narrative text, tables, maps, and figures. Studies lacking interpretable spatial content were excluded. Studies with redundant, unverifiable, or low-quality data were also excluded, with limited exceptions discussed in the processing steps.
   The spatial extent of the TD dataset is limited to areas of the continental margin proximal to active or proposed offshore renewable energy planning or lease areas as of April 2024. This spatial domain spans the Outer Continental Shelf and Rise from the U.S. Southeast through the Northeast Atlantic, and along the Pacific margin off the coast of California. Regions without active leasing, such as the Pacific Northwest and Gulf of Mexico, were not included in the inventory.
   Source quality and thus spatial precision varies considerably among entries. In some cases, domains were derived directly from public vector or raster datasets. In others, domains were created by georeferencing figures or buffering from reported locations. Spatial processing methods are documented in the attribute field DOMAIN_M. Some TD domains reflect precise boundaries, while others are generalized to approximate zones of study.
   Hazard classification fields were populated when the source provided sufficient detail to characterize hazard presence or absence within the domain. When no interpretable information was available for a specific hazard, a value of 'NA' was assigned. Not all studies yielded interpretable information for every hazard, and terminology and methodological approaches varied widely. Where hazards were sufficiently described, relevant content was distilled into notes fields that accompany each classification. These notes provide summarized or directly quoted interpretations and supporting context and are intended to guide users but not replace the source documentation.
5. How consistent are the relationships among the observations, including topology?
   Records were included which contain interpretable content, defined as qualitative or quantitative information that supported classification of one or more hazard types based on their attribute definitions. Supporting context could be explicit (e.g., direct identification of a hazard) or implicit (e.g., inference from mapped features, figures, or results). Hazard types were assessed independently and assigned only when sufficient evidence supported classification. Notes fields contextualize the basis for each classification. 'NA' indicates that data were insufficient for classification of that hazard, not the absence of the hazard.
   Spatial domains represent an approximation of the interpreted extent of the study area and should not be assumed to precisely reflect the specific location or distribution of hazards. Where source material constrained the spatial footprint more narrowly (e.g., to a specific transect or feature), this detail is reflected in the notes field. All domain creation methods were recorded in the DOMAIN_M field.
   Domain approximations are captured by the processing steps in DOMAIN_M. To provide an example, in the OI dataset, some domains were approximated on the location of individual infrastructure components (e.g., meteorological buoys or towers) when broader survey areas (e.g., SAP APEs) were not publicly defined. These points represent the reported location of the asset, not necessarily the center or bounds of the survey area. For example, the VOWTAP cable corridor was approximated using Marine Cadastre's 'Submarine Cable Areas' layer due to the absence of a publicly available 300-meter survey corridor.
   Export Cable Corridor (ECC) domains were approximated using published features as detailed in the processing steps. Most ECC features were derived from the 'Offshore Wind - Export Cable Corridors (Proposed)' layer hosted on Marine Cadastre (version: December 21, 2023; coordinate system: GCS WGS 1984). An exception is the ECC for the Virginia Offshore Wind Technology Advancement Project (VOWTAP), which was based on the 'Submarine Cable Areas' layer (version: May 1, 2023; coordinate system: GCS NAD83) due to the absence of a publicly available 300-meter survey corridor.
   OI_GHZD_Polygons: Contains 54 unique polygons. Each polygon is associated with a LEASE_NUMB, and multiple polygons can be associated with a single LEASE_NUMB value.
   In the OI_GHZD_Table, unique areas are defined by a combination of the attributes 'LEASE_NUMB' and 'UNID_P'. For each unique combination, there are 34 separate 'GHZD' attribute enumerated values.
   In the OI_GHZD_Table, a dependency applies to some of the GHZD attributes with respect to the identification of that feature. The attribute value for 'Bedform migration' has an attribute value set for IDEN if the following condition is met: one or more of the following GHZD attribute values has an IDEN value of 'Y' - Megaripples, Ripples, Sand ridges, Sand waves, Unclassified bedforms. However, it is possible for Bedform migration to have an IDEN value of 'Y', and none of those specific GHZD IDEN values of 'Y' depending on the source of information and what specificity is included in that source.
   In a similar manner, the attribute value for GHZD Glacial till has the IDEN value set to 'Y' if that same comprehensive location has a GHZD Moraine IDEN value set to 'Y'. The presence of Glacial till does not necessarily mean the presence of a Moraine.
   In the TD dataset, domain boundaries were interpreted from study extents - either mapped directly or inferred through georeferenced figures, descriptive text, or public feature layers. Where domain boundaries were not explicitly stated, generalized domains were created using consistent rules and documented as geoprocessing steps within DOMAIN_M.
   For the TD dataset, sources were required to provide interpretations, except bathymetry. Bathymetric datasets were included even when unaccompanied by explicit interpretations, as they provide spatially continuous morphological context that can be readily reinterpreted to evaluate several hazard types.
   In the TD table, whenever a DOI is available, the link to the source is the DOI link with one exception. For that one exception, the DOI link is a broken link that the publisher had not fixed by the time these data were released, hence providing the direct link to the publication (DOI is 10.2110/jsr.2020.69, publication link is https://pubs.geoscienceworld.org/sepm/jsedres/article/90/11/1510/593830/The-evolution-of-coastal-plain-incised-valleys).
   In the TD dataset, although the Shape attribute geometry indicates ZM (implying both elevation and measure values associated with each vertex), this is erroneous. There are no Z or M measurements associated with polygon vertices and is a remnant of the original work through a file geodatabase. The decision was made not to attempt to “fix” the erroneous information at the final stages of release for fear of damaging the dataset and the ZM geometry designation does not impact the data use.
   Although both the TD and OI datasets have values of 'Y' and 'NA' with reference to hazard identification, only the OI table uses the value of 'N'. The OI dataset can employ 'N' because the source material often explicitly states the negative occurrence of a hazard within a BOEM-approved system of characterizing hazards. In contrast, the source material used in the TD dataset were collected for a multitude of objectives using multiple techniques and, thus, do not systematically exclude the presence of specific hazards.

How can someone get a copy of the data set?

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
   

   USA

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? The dataset is comprised of a GeoPackage (USGS_GHZD_DB.gpkg), browse graphic (GOM_BOEM_OCS_A0567.png), symbology files (in the zip file symbology_files.zip), and FGDC CSDGM metadata. The GeoPackage consists of the TD feature layer (TD_GHZD_FC), the OI polygons (OI_GHZD_Polygons), and the OI attribute table (OI_GHZD_Table). Additionally, there is a 'view' (OI_GHZD_Join_View) which acts as a one-to-many join between the OI polygon and OI attribute table. Accompanying the GeoPackage are symbology files for both the OI (in the OI folder) and TD (in the TD folder) data zipped into a single folder, along with an image of the required folder structure. The symbology zip files also contains a ReadMe.txt file to help explain the necessary folder structure to enable the use of the symbology files. These files are provided as LYRX files compatible with ArcGIS Pro and QLR files compatible with QGIS.
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 for other purposes, nor on all computer systems, 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:	information content in format geopackage (GPKG) (version Created in ArcGIS Pro v. 3.4, subsequent edits in QGIS 3.4 or Navicat Premium v. 16 database management tool.) Size: 70
     Network links:	https://www.sciencebase.gov/catalog/file/get/67dacd32d34ef1653388702f https://www.sciencebase.gov/catalog/item/67dacd32d34ef1653388702f https://doi.org/10.5066/P1SLUTW9

   • Cost to order the data: none

5. What hardware or software do I need in order to use the data set?
   These data are distributed in the GeoPackage format, an open, standards-based format utilizing SQLite as the storage engine which is accessible by numerous GIS software packages.

Who wrote the metadata?

Dates:

Last modified: 26-Sep-2025

Metadata author:

U.S. Geological Survey

Attn: VeeAnn A. Cross

Marine Geologist

384 Woods Hole Rd.

Woods Hole, MA

USA

(508) 548-8700 x2251 (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 the USGS.

Metadata standard:

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