Metadata: Identification_Information: Citation: Citation_Information: Originator: Christopher Galley Originator: Daniel Sorenson Originator: Isabelle M. Shapiro Originator: Amy Gartman Publication_Date: 20260401 Title: Magnetics Data from the Escanaba Trough (Gorda Ridge) Geospatial_Data_Presentation_Form: comma-delimited text Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P1DRPIQK Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Other_Citation_Details: Suggested Citation: Galley, C., Sorenson, D., Shapiro, I.M., and Gartman, A., 2026, Magnetics Data from the Escanaba Trough (Gorda Ridge): U.S. Geological Survey data release, https://doi.org/10.5066/P1DRPIQK. Online_Linkage: https://doi.org/10.5066/P1DRPIQK Description: Abstract: This data release provides access to magnetics data collected by the AUV Sentry during the TN403 cruise in the Escanaba Trough (USGS Field Activity 2022-621-FA). Purpose: These data serve to expand the knowledge and statistics for deep ocean marine mineral occurrences and composition within the global ocean. Supplemental_Information: Additional information about the field activity or activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2022-621-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20220712 Ending_Date: 20260123 Currentness_Reference: Magnetics data compiled and processed Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -127.5671 East_Bounding_Coordinate: -127.4024 North_Bounding_Coordinate: 41.1735 South_Bounding_Coordinate: 40.6942 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5218d4c6-701d-4225-8cf2-9df71c99ca5c Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Theme_Keyword: magnetic anomaly Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: substrate Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) Keywords Theme_Keyword: continental margin Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: magnetic field (earth) Theme_Keyword: magnetometer measurement Theme_Keyword: aeromagnetic surveying Theme_Keyword: metallic mineral resources Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Pacific Ocean Place: Place_Keyword_Thesaurus: NGA GEOnet Names Server (GNS) Place_Keyword: Escanaba Trough Place_Keyword: Gorda Ridge Access_Constraints: No access constraints. Please see 'Distribution Information' for details. Use_Constraints: USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. These data are marked with a Creative Common CC0 1.0 Universal License. Please recognize and acknowledge the U.S. Geological Survey and the University of Ottawa as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: PCMSC Science Data Coordinator Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Address: Address_Type: mailing Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Native_Data_Set_Environment: The data was processed on with Woods Hole Oceanographic Institute's full-vector calibration program, written by Dr. Maurice Tivey in MATLAB. MATLAB was operated on a Windows 10 system. Cross_Reference: Citation_Information: Originator: Christopher Galley Originator: Peter G. Lelièvre Originator: Amir Haroon Originator: Sebastian Graber Originator: John Jamieson Originator: Florent Szitkar Originator: Isobel Yeo Originator: Colin G. Farquharson Originator: Sven Petersen Originator: Robert Evans Publication_Date: 2021 Title: Magnetic and Gravity Surface Geometry Inverse Modeling of the TAG Active Mound Other_Citation_Details: Galley, C., Lelievre, p., Haroon, A., Graber, S., Jamieson, J., Szitkar, F., Yeo, I., Farquharson, C., Petersen, S., and Evans,R. (2021). Magnetic and gravity surface geometry inverse modeling of the TAG active mound. Journal of Geophysical Research: Solid Earth, 126, e2021JB022228. https://doi.org/10.1029/2021JB022228. Citation added for users reference in metadata descriptions. Online_Linkage: https://doi.org/10.1029/2021JB022228 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The noise levels for the final processed total magnetic intensity were determined to have a mean of 0.0 and a standard deviation of 8 percent (assuming Gaussian noise). This value was determined during the inversion modelling process, where multiple models were produced with varying data misfit targets (such as, the difference between the observed data and the final inversion model's calculated data), until a model was produced with minimal-to-no near-seafloor, small (single cell sized), high magnetic susceptibility artifacts interpreted to represent overfitting the data. This 8 percent standard deviation noise is likely so high because it incorporates positional inaccuracy of the survey platform (the AUV Sentry), see Galley and others (2021) in the Supplementary Material of the publication for details. Logical_Consistency_Report: The data does match with details provided about it, and all data falls within expected ranges. No duplicates are present in the files. Completeness_Report: Total magnetic intensity data is geographically dependent, such as, values can change greatly depending on where the survey took place. This data only represents total magnetic intensity data within the corresponding survey areas, in the spring of 2022. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Sentry’s internal navigation is dead reckoning based on the Inertial Navigation System (INS) and Doppler Velocity Log (DVL) sonar system. It has a typical accuracy of 0.1 percent of distance traveled. The Sentry dives at the Escanaba Trough were between 24-51 km in survey distance travelled, corresponding to positional accuracies of 24-51 m by the end of the surveys. However, post-processing can greatly increase the accuracy of the positional data. A better estimate of the horizontal accuracy of the Sentry AUV would be 6-8 m, as determined through testing in Galley and others (2021). Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Sentry's depth information is much more accurate than the horizontal positional data, as it is determined through pressure measurements (using a Parascientific 8B7000-1m Digiquartz depth sensor). The depth sensor boasts a 0.01 percent accuracy, so the average survey depth at the Escanaba Trough of approximately 3.2 km would correspond to a survey depth data accuracy of approximately 32 cm. Lineage: Process_Step: Process_Description: Magnetics data was collected by a three-component fluxgate magnetometer attached the autonomous underwater vehicle (AUV) Sentry during the TN403 expedition in the Escanaba Trough on the R/V Thomas G. Thompson. The expedition occurred between May 24, 2022, and June 13, 2022, and was led and staffed by USGS employees. Process_Date: 20220613 Process_Step: Process_Description: Magnetics data were compiled and cleaned upon returning to land. To remove the magnetization effects from the AUV, a full-vector calibration was performed, which involved spinning the AUV in the water column to complete at least one 360-degree rotation. The attitude and vector magnetic field data from these rotations were used to calculate the induced and permanent magnetization of the AUV using a least-squares solution and subsequently removed from the raw data. The resulting files from this initial calibration are, which also include raw data columns: escanaba_d638_mag.csv; escanaba_d639_mag.csv; escanaba_d640_mag.csv; escanaba_d641_mag.csv; escanaba_d642_mag.csv; escanaba_d643_mag.csv; escanaba_d646_mag.csv; escanaba_d647_mag.csv. The calibration matrices used in the full-vector calibration are included in the file Calibration_Coefficient_Matrices.txt. To further prepare the vector magnetic data for the inversion modelling the data were: (1) low-pass filtered with a passband frequency of 0.01 Hz at a data frequency of 10 Hz; (2) projected to WGS 1984 UTM Zone 9N; (3) separated into single survey lines with the ends of the lines where the AUV turned around removed, each line was levelled to its survey's tie line(s); (4) further linear heading corrections were calculated and applied to each individual survey line, to remove artifacts left over from the full-vector calibration; (5) a 50 m moving mean was applied to the data along each survey line, and then the data was subsampled to a 50 m data point spacing; (6) the survey lines were combined into new survey groups, with dive 643's data being separated into two surveys, d643_1 and d643_23, and dive 638, 640, and 641 were combined into a single group; and (7) the Earth's field strength was calculated at each survey location using the WMM-2020 model (https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#igrfwmm), and was subtracted from the data to produce a TMI anomaly. The resulting data files are: d638_mag_lvled_50m_UTM9N.csv; d639_mag_lvled_50m_UTM9N.csv; d640_mag_lvled_50m_UTM9N.csv; d641_mag_lvled_50m_UTM9N.csv; d642_mag_lvled_50m_UTM9N.csv; d646_mag_lvled_50m_UTM9N.csv; d647_mag_lvled_50m_UTM9N.csv. Process_Date: 20260123 Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Vector data of the X, Y, and Z directions of the magnetic field were during each of AUV Sentry's dive while the magnetometer was attached. Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0000001 Longitude_Resolution: 0.0000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: World Geodetic System 1984 (WGS 84) Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257223563 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: mean sea level Altitude_Resolution: 0.1 Altitude_Resolution: 0.1 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: escanaba_dXXX_mag.csv Entity_Type_Definition: Comma Separated Value (CSV) file containing raw magnetics data. The XXX in the file name represents the dive number. For example, escanaba_d638_mag.csv contains data from dive 638. Entity_Type_Definition_Source: Producer Defined Attribute: Attribute_Label: Year Attribute_Definition: The year component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2022 Range_Domain_Maximum: 2022 Attribute_Units_of_Measure: years Attribute: Attribute_Label: Month Attribute_Definition: The month component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 5 Range_Domain_Maximum: 6 Attribute_Units_of_Measure: months Attribute: Attribute_Label: Day Attribute_Definition: The day component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 31 Attribute_Units_of_Measure: days Attribute: Attribute_Label: Hour Attribute_Definition: The hour component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 23 Attribute_Units_of_Measure: hours Attribute: Attribute_Label: Minute Attribute_Definition: The minute component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 59 Attribute_Units_of_Measure: minutes Attribute: Attribute_Label: Second Attribute_Definition: The second component of the data's timestamp Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 60 Attribute_Units_of_Measure: seconds Attribute: Attribute_Label: Longitude_DD Attribute_Definition: Longitudinal data formatted in decimal degrees Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -127.5671398 Range_Domain_Maximum: -127.4023971 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: Latitude_DD Attribute_Definition: Latitudinal data formatted in decimal degrees Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 40.6942229 Range_Domain_Maximum: 41.1735022 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: Elevation_m Attribute_Definition: Elevation data of the observation points relative to sea-level, units in meters (m) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -3273.01 Range_Domain_Maximum: -3086.87 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Altitude_m Attribute_Definition: Altitude data formatted in meters. This represents the relative height of the observation points above the seafloor Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 49.34 Range_Domain_Maximum: 127.37 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Heading Attribute_Definition: Heading data of the AUV Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0 Range_Domain_Maximum: 360.0 Attribute_Units_of_Measure: degrees Attribute: Attribute_Label: Pitch Attribute_Definition: Pitch data of the AUV Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -11.85 Range_Domain_Maximum: 11.301 Attribute_Units_of_Measure: degrees Attribute: Attribute_Label: Roll Attribute_Definition: Pitch data of the AUV Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -3.379 Range_Domain_Maximum: 6.815 Attribute_Units_of_Measure: degrees Attribute: Attribute_Label: Mag_x_raw_nT Attribute_Definition: The x-component (North positive) of the raw magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -29991.87 Range_Domain_Maximum: 28199.46 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: Mag_y_raw_nT Attribute_Definition: The y-component (East positive) of the raw magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -25141.69 Range_Domain_Maximum: 24708.65 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: Mag_z_raw_nT Attribute_Definition: The x-component (North positive) of the raw magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 38935.41 Range_Domain_Maximum: 49413.95 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: TMI_raw_nT Attribute_Definition: The total magnetic intensity raw data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 43661.5 Range_Domain_Maximum: 51478.94 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: Mag_x_veccorr_nT Attribute_Definition: The x-component (North positive) of the vector-corrected magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19060.95 Range_Domain_Maximum: 23426.19 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: Mag_y_veccorr_nT Attribute_Definition: The y-component (East positive) of the vector-corrected magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2767.21 Range_Domain_Maximum: 8150.08 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: Mag_z_veccorr_nT Attribute_Definition: The z-component (vertical, down positive) of the vector-corrected magnetic field data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 37052.03 Range_Domain_Maximum: 45919.48 Attribute_Units_of_Measure: nano tesla Attribute: Attribute_Label: TMI_veccorr_nT Attribute_Definition: The total magnetic intensity vector-corrected data. Units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 42218.74 Range_Domain_Maximum: 51085.81 Attribute_Units_of_Measure: nano tesla Detailed_Description: Entity_Type: Entity_Type_Label: dXXX_mag_lvled_50m_UTM9N.csv Entity_Type_Definition: Comma Separated Value (CSV) file containing processed magnetics data. The XXX in the file name represents the dive number. For example, d638_mag_lvled_50m_UTM9N.csv contains data from dive 368. Entity_Type_Definition_Source: Producer Defined Attribute: Attribute_Label: Easting_m Attribute_Definition: Easting positional data, in the WGS 1984 UTM Zone 9 projection. Units in meters (m) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 620722.4 Range_Domain_Maximum: 633887.4 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Northing_m Attribute_Definition: Northing positional data, in the WGS 1984 UTM Zone 9 projection. Units in meters (m) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 4505892.6 Range_Domain_Maximum: 4559228.9 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Elevation_m Attribute_Definition: Elevation data of the observation points relative to sea-level, units in meters (m) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -3272.8 Range_Domain_Maximum: -3087.0 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Altitude_m Attribute_Definition: Altitude data formatted in meters. This represents the relative height of the observation points above the seafloor Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 63.7 Range_Domain_Maximum: 91.7 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: TMI_Anomaly_nT Attribute_Definition: The total magnetic intensity anomaly data, units in nano tesla (nT) Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -415.9 Range_Domain_Maximum: 2597.6 Attribute_Units_of_Measure: nano tesla Overview_Description: Entity_and_Attribute_Overview: This dataset consists of data from eight marine magnetic field surveys collected down the length of the Escanaba Trough in the northeast Pacific Ocean. The data were measured with a three-component fluxgate magnetometer, mounted to Woods Hole Oceanographic Institute's autonomous underwater vehicle Sentry. Included in this dataset are the eight survey's calibrated vector (three-component) magnetic data, as well as the processed versions of the data presented as total magnetic intensity. Entity_and_Attribute_Detail_Citation: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - CMGDS Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: comma-delimited text Format_Version_Number: 2025a Format_Information_Content: These data are available in comma-delimited text format accompanied by the associated CSDGM FGDC-compliant metadata. Files are provided in two zip folders as the final data (final_data_used_in_modeling) and the vector corrected data (vector_corrected). File_Decompression_Technique: No compression applied. Transfer_Size: 146.5 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5066/P1DRPIQK Access_Instructions: Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the Magnetic Data section. Fees: None Technical_Prerequisites: These data can be viewed with any text reader. Metadata_Reference_Information: Metadata_Date: 20260401 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: PCMSC Science Data Coordinator Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Address: Address_Type: mailing Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Country: USA Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998