Metadata: Identification_Information: Citation: Citation_Information: Originator: Phillips, Stephen C. Originator: Pohlman, J.W. Originator: Casso, M. Publication_Date: 2025 Title: Molecular (C1-C5 hydrocarbon, CO2, O2, and N2) and δ13C-CH4 composition of pressure core, void, and hydrate gases from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site Edition: 1 Series_Information: Series_Name: dataset Issue_Identification: DOI:10.5281/zenodo.15626975 Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts, USA Publisher: U.S Geological Survey, Coastal and Marine Hazards and Resources Program Other_Citation_Details: Suggested citation: Phillips, S.C., Pohlman, J.W., and Casso, M., 2025, Molecular (C1-C5 hydrocarbon, CO2, O2, and N2) and δ13C-CH4 composition of pressure core, void, and hydrate gases from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site H [Dataset]: Zenodo, https://doi.org/10.5281/zenodo.15626975 Online_Linkage: https://doi.org/10.5281/zenodo.15626975 Description: Abstract: These data include composition of void gas, pressure core gas, and hydrate gas samples collected from the Terrebonne Basin in the Gulf of America (Gulf of Mexico) at Walker Ridge Site H, Holes H003 and H002. Cores were collected during drilling as part of the Deepwater Hydrate Coring Expedition (UT-GOM2-2) in August 2023. This U.S. Department of Energy funded project was focused on better understanding microbial methane generation in marine sediments and characterizing coarse-grained gas hydrate reservoirs. Sediments were recovered continuously down to 155 meters below the seafloor and as spot cored intervals down to 861 meters below the seafloor. Cores were recovered using both conventional and pressure cores. Gas samples were collected from both conventional and pressure cores in order to understand the source of gases in Terrebonne Basin sediments. Gas samples were analyzed for C1-C5 hydrocarbon, CO2, O2, N2, and δ13C-CH4 composition using gas chromatography and cavity ringdown spectroscopy. Purpose: The molecular and isotopic composition of hydrocarbon gases can be used to constrain the source of gas in hydrate-bearing sediments. Measurement of oxygen and nitrogen is to track atmospheric contamination. Supplemental_Information: This Microsoft Excel workbook contains data in a single tab. The samples were collected from cores recovered during the UT-GOM2-2 expedition in 2023. All samples were collected either during offshore operations in August 2023 or onshore operations in September 2023. Additional information with regards to the offshore operations (field activity 2023-021-FA) can be found at https://cmgds.marine.usgs.gov/services/activity.php?fan=2023-021-FA Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20230804 Ending_Date: 20230827 Currentness_Reference: Ground condition. Cores were collected in August 2023 on the D/V Q4000 using conventional (advanced piston coring and extended core barrel coring) and pressure coring (Pressure Coring Tool with Ball Valve). Void gases were collected from conventional cores immediately after recovery by drilling a hole through the core liner. Pressure cores were collected from a bubbling chamber (an inverted graduated cylinder) during pressure core degassing. Hydrate gases were collected from cryo-frozen hydrate-bearing sediment samples that were dissociated inside a syringe used to collect the gas. Status: Progress: Complete Maintenance_and_Update_Frequency: Future version expected with analysis of additional gas samples. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -91.67608 East_Bounding_Coordinate: -91.67599 North_Bounding_Coordinate: 26.66260 South_Bounding_Coordinate: 26.66228 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Woods Hole Coastal and Marine Science Center Theme_Keyword: WHCMSC Theme_Keyword: U.S. Department of Energy Theme_Keyword: DOE Theme_Keyword: National Energy Technology Laboratory Theme_Keyword: NETL Theme_Keyword: University of Texas at Austin Theme_Keyword: UT-Austin Theme_Keyword: methane hydrates Theme_Keyword: carbon cycle Theme_Keyword: gas analysis Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: drilling and coring Theme_Keyword: piston coring Theme_Keyword: rotary drilling Theme_Keyword: core analysis Theme_Keyword: chemical analysis Theme_Keyword: diagenesis Theme_Keyword: gas chromatography Theme_Keyword: light stable isotope analysis Theme_Keyword: interagency programs Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:26031589-92db-464b-9ee1-1ae82c713d3e Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Gulf of America Place: Place_Keyword_Thesaurus: None Place_Keyword: Terrebonne Basin Place_Keyword: Gulf of Mexico Place_Keyword: Walker Ridge Protraction Area Access_Constraints: No access constraints. Please see 'Distribution Information' for details. Use_Constraints: Public domain (CC0-1.0) data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. All data collection was funded by the U.S. Department of Energy National Energy Technology Laboratory. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Stephen Phillips Contact_Organization: U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Contact_Position: Research Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-457-8700 x2240 Contact_Electronic_Mail_Address: scphillips@usgs.gov Data_Quality_Information: Logical_Consistency_Report: For each of the gas measurements described in the Process Steps below, standards relevant to the particular property were entrained in the measurement sequence to ensure fidelity within each Process Step. The standards are noted in the Process Steps as well as the citations for those references. Completeness_Report: This Microsoft Excel workbook represents the complete collected and calculated data in support of dual-frequency magnetic susceptibility measurements for the UT-GOM2-2 project. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal position was determined by GPS satellite data, which provided guidance information for the dynamic positioning system (DPS) utilized by the D/V Q4000. The DPS also utilizes inputs from current, wind, tide, and wave data to control eight azimuthal thrusters beneath the ship’s hull. The thrusters are capable of 360-degree adjustment. Given the DPS capabilities, borehole locations for the D/V Q4000 are considered to be accurate to a radius of 15 meters. Details for a very similar DPS system us provided in: Chikyu Hakken – Earth Discovery, Volume 1, Spring 2005, published by JAMSTEC’s Center for Deep Earth Exploration: https://www.jamstec.go.jp/chikyu/e/magazine/backnum/pdf/hk_01_e.pdf North American Datum 27 (NAD27) is the horizontal datum used by the DPS on the D/V Q4000. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Coring depth measurements used on the D/V Q4000 during the UT-GOM2-2 expedition followed standard International Ocean Discovery Program (IODP) protocols using analogous coring tools. Assessment of these protocols by IODP had determined the vertical position accuracy is on the order of centimeters to meters relative to each coring point, depending on core recovery. Additional information about the depth conventions and accuracy are on pages 8 and 9 of the IODP report “IODP Depth Scales Terminology”: http://www.iodp.org/policies-and-guidelines/142-iodp-depth-scales-terminology-april-2011/file. Depth resolution ranges from 0.01 to 1 meter. Lineage: Process_Step: Process_Description: Sediment cores were collected via wireline coring tools (advance piston coring, extended core barrel coring, and pressure coring) and cut into sections at sea. Hole H002 is located at 26.66228° latitude and -91.67601° longitude at the seafloor. Hole H003 is located at 26.66263° latitude and -91.67599° latitude at the seafloor. Void gases were collected using a syringe and a puncture tool that penetrates the core liner. Pressure core gases were collected from an inverted graduated cylinder as part of the quantitative degassing system that collects gases produced from the core storage chamber during depressurization. Hydrate gases were collected from cryogenically frozen samples that were allowed to dissociate within a syringe. Void gas, pressure core gas, and hydrate gas were collected in Cali-5 Bond gas bags and were analyzed for gas composition and methane stable carbon isotopes at the U.S. Geological Survey Woods Hole Coastal and Marine Science Center using the Automated Sample Introduction Module (Auto-SIM) Gas Chromatography/Cavity Ring-Down Spectroscopy System (Auto-SIM GC/CRDS). Gas samples in Cali-5 Bond bags were attached to the 16-port Auto-SIM that automatically transfers a portion of each sample to a series of samples loops of the Auto-SIM GC/CRDS that includes the USGS Discrete Sample Introduction Module (DSIM) with a cavity ring-down spectrometer and a Scientific Research Instruments (SRI) MultipleGas#5 (MG5) gas chromatograph (GC) equipped with sample loops and injection valves for parallel analysis by flame ionization detection (FID) and thermal conductivity detection (TCD). The DSIM contains a fixed (low-volume) internal sample loop and a replaceable external sample loop (larger-volume) that allows the user to properly dilute gases so they’re within the ideal analytical range of a Picarro G2201-I CRDS (100-600 ppm). The CRDS measures methane and CO2 concentrations and stable carbon isotopes of each (see Pohlman and others (2021) for additional details). Isotope ratios measured by the CRDS are reported in the -notation (δ13C) relative to a Vienna Pee Dee Belemnite (VPDB) standard calibration. Measurement precision for methane isotope ratios improves from 1‰ at 10 ppm to less than 0.2‰ at 30 ppm and remains constant through the range of measurements made. The average sample precision for this project was 0.18‰ for methane carbon isotope ratios. Additional details of the gas collection and analysis procedures are described in Flemings and others, 2025. Reference: Flemings, P.B., Thomas, C., Phillips, S.C., Collett, T.S., Cook, A.E., Solomon, E., Colwell, F.S., Johnson, J.E., Awwiller, D., Aylward, I., Bhandari, A.R., Brooks, D., Buser-Young, J.Z., Cardona, A., Casso, M., Coyte, R., Darrah, T., Davis, M., Dugan, B., Duncan, D., Germaine, J.T., Holland, M., Houghton, J., Mills, N.T., Mimitz, M., Minarich, D., Morono, Y., Murphy, Z., O’Connell, J., Petrou, E., Pettigrew, T., Pohlman, J.W., Portnov, A., Phillips, M.P., Redd, T., Sawyer, D. E., Schultheiss, P., Shannon, K., Sullivan, C., Small, C., Tozier, K., Tsang, M.-Y., Maal, C.V.D., Waite, W.F., and Walton, T., 2025, Expedition UT-GOM2-2 Methods, in Flemings, P.B., ed., Proceedings of the Deepwater Hydrate Coring Expedition UT-GOM2-2: The University of Texas at Austin, University of Texas Institute for Geophysics, https://doi.org/10.5281/zenodo.13971228. Pohlman, J.W., Casso, M., Magen, C., and Bergeron, E., 2021, Discrete Sample Introduction Module for Quantitative and Isotopic Analysis of Methane and Other Gases by Cavity Ring-Down Spectroscopy: Environmental Science and Technology, v. 55, p. 12066-12074, https://doi.org/10.1021/acs.est.1c01386 Process_Date: 2024 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Stephen Phillips Contact_Organization: U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Contact_Position: Research Geologist Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-457-8700 x2240 Contact_Electronic_Mail_Address: scphillips@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 79 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.00001 Longitude_Resolution: 0.00001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: NAD 27 Ellipsoid_Name: Clark ellipsoid of 1866 Semi-major_Axis: 6378206.400000 Denominator_of_Flattening_Ratio: 294.9786982 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: local surface - depth below sea floor Depth_Resolution: 0.005 Depth_Distance_Units: meters Depth_Encoding_Method: attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: "UT-GOM2-2_USGS-gas-data.xlsx" Entity_Type_Definition: Microsoft Excel workbook that contains tabulated gas composition data by depth for UT-GOM2-2 cores. Entity_Type_Definition_Source: producer defined Attribute: Attribute_Label: Expedition Attribute_Definition: Expedition name. UT-GOM2-2 for all entries Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined text field Attribute: Attribute_Label: Area Attribute_Definition: Lease block area within the Gulf of America. All values are Walker Ridge 313 (WR313). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined text field Attribute: Attribute_Label: Site Attribute_Definition: Site within the WR313 area. In this case all from the H site. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined text field Attribute: Attribute_Label: Hole Attribute_Definition: Two holes were drilled at the WR313 H site: Holes 002 and 003. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined text field Attribute: Attribute_Label: Core Attribute_Definition: Core number, increasing with depth in each hole. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined Attribute: Attribute_Label: Core type Attribute_Definition: Core type used to recover core. H is advanced piston core, X is extended core barrel, CS is pressure coring tool with ball valve in the cutting shoe configuration, and FB is the pressure coring tool with ball valve in the face bit configuration. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined Attribute: Attribute_Label: Section Attribute_Definition: Section cut within the core. Increasing number within the core with the core catcher (CC) as the bottom section Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined Attribute: Attribute_Label: Piece Attribute_Definition: Piece cut within each core section. Some sections were not cut into pieces. NaN = no data. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined Attribute: Attribute_Label: Sample type Attribute_Definition: Void gas was collected from voids within the core liner in conventional cores. Pressure core gas was collected from gas produced during depressurization of pressure cores. Hydrate gas was collected from cryo-frozen cores in which hydrate-bearing sediment was allowed to dissociate within a syringe. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Unrepresentable_Domain: user defined Attribute: Attribute_Label: Gas bag # Attribute_Definition: Number label on each Cali-5 bond gas bag. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 800 Range_Domain_Maximum: 880 Attribute_Units_of_Measure: no unit Attribute: Attribute_Label: Pressure core step (bar) Attribute_Definition: Pressure within the pressure core storage chamber when the gas sample was collected. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 30 Attribute_Units_of_Measure: bar Attribute: Attribute_Label: Compressed sample top depth (mbsf) Attribute_Definition: Sample top depth in meters below seafloor (mbsf) based on linearly-compressed core depths, accounting for expansion of the core (total length of core = length of drilling advance). Equivalent to IODP CSF-B terminology. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19.64 Range_Domain_Maximum: 818.69 Attribute_Units_of_Measure: meters below seafloor (mbsf) Attribute: Attribute_Label: Compressed sample bottom depth (mbsf) Attribute_Definition: Sample bottom depth in meters below seafloor (mbsf) based on linearly-compressed core depths, accounting for expansion of the core (total length of core = length of drilling advance). Equivalent to IODP CSF-B terminology. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19.64 Range_Domain_Maximum: 818.87 Attribute_Units_of_Measure: meters below seafloor (mbsf) Attribute: Attribute_Label: Methane (%) Attribute_Definition: Concentration of methane (C1) within the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.04 Range_Domain_Maximum: 100.00 Attribute_Units_of_Measure: percent (%) Attribute: Attribute_Label: δ13C-CH4 (‰) Attribute_Definition: δ13C of methane relative to Vienna Pee Dee Belemnite (VPDB). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -83.5 Range_Domain_Maximum: -69.9 Attribute_Units_of_Measure: per mil (‰) Attribute: Attribute_Label: CO2 (ppm) Attribute_Definition: Concentration of carbon dioxide in the sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 197 Range_Domain_Maximum: 11052 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: Ethane (ppm) Attribute_Definition: Concentration of ethane (C2) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.8 Range_Domain_Maximum: 114.8 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: Propane (ppm) Attribute_Definition: Concentration of propane (C3) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 8 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: C1/(C2+C3) Attribute_Definition: Ratio of methane (C1) to ethane (C2) plus propane (C3). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 8076 Range_Domain_Maximum: 63201 Attribute_Units_of_Measure: no unit Attribute: Attribute_Label: C1/C2 Attribute_Definition: Ratio of methane (C1) to ethane (C2). Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 8076 Range_Domain_Maximum: 80025 Attribute_Units_of_Measure: no unit Attribute: Attribute_Label: i-Butane (ppm) Attribute_Definition: Concentration of isobutane (i-C4) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 6 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: n-Butane (ppm) Attribute_Definition: Concentration of normal butane (n-C4) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 3 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: neo-Pentane (ppm) Attribute_Definition: Concentration of neopentane (neo-C5) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2 Range_Domain_Maximum: 2 Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: i-Pentane (ppm) Attribute_Definition: Concentration of isopentane (i-C5) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: b.d. Range_Domain_Maximum: b.d Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: n-Pentane (ppm) Attribute_Definition: Concentration of normal pentane (n-C5) in the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: b.d. Range_Domain_Maximum: b.d. Attribute_Units_of_Measure: parts per million (ppm) Attribute: Attribute_Label: Oxygen (%) Attribute_Definition: Concentration of oxygen within the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.77 Range_Domain_Maximum: 20.23 Attribute_Units_of_Measure: percent (%) Attribute: Attribute_Label: Nitrogen (%) Attribute_Definition: Concentration of nitrogen within the gas sample. Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: b.d. Range_Domain_Maximum: 80.40 Attribute_Units_of_Measure: percent (%) Overview_Description: Entity_and_Attribute_Overview: The workbook UT-GOM2-2_USGS-gas-data.xlsx contains one tab. The first row in the XLSX file is a header row. The remaining rows contain all data included in this data release, with non-measurements given by “NaN" as indicated in the attribute definitions in this xml file. Measurements that had concentrations below detection are listed as “b.d.” This file is part of a data release posted to the Zenodo UT-GOM2-2 community. Entity_and_Attribute_Detail_Citation: Phillips, S.C., Pohlman, J.W., and Casso, M (2025). Molecular (C1-C5 hydrocarbon, CO2, O2, and N2) and δ13C-CH4 composition of pressure core, void, and hydrate gases from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site H [Dataset]. Zenodo. https://doi.org/10.5281/zenodo.15626975. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Zenodo Contact_Address: Address_Type: mailing and physical address Address: European Organization for Nuclear Research: IT Department, Digital Repositories Section City: Meyrin State_or_Province: Geneva Postal_Code: 1211 Country: Switzerland Contact_Voice_Telephone: +41 22 76 77777 Contact_Electronic_Mail_Address: info@zenodo.org Resource_Description: Zenodo makes research results citable, and through OpenAIRE, integrates them into existing reporting lines to funding agencies. Citation information is also passed to DataCite and onto the scholarly aggregators. UT-GOM2-2_USGS-gas-data.xlsx (Excel spreadsheet of data). The Zenodo site does not have the complete XML metadata. Distribution_Liability: Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: XLSX Format_Version_Number: Created in Excel Office 365 version 2408 Transfer_Size: 1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5281/zenodo.15626975 Access_Instructions: The link is the DOI link to the data release landing page where the data can be downloaded. Fees: None. Metadata_Reference_Information: Metadata_Date: 20251208 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Stephen C. Phillips Contact_Organization: U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Contact_Position: Research Geologist Contact_Address: Address_Type: mailing and physical Address: U.S. Geological Survey Address: 384 Woods Hole Rd. City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2240 Contact_Electronic_Mail_Address: whsc_data_contact@usgs.gov Contact_Instructions: The metadata contact email address is a generic address in the event the person is no longer with USGS. Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: None Metadata_Use_Constraints: None