Navigable Area 2022 H13626 Louisiana Northern Gulf of Mexico 40 NM East of Pass A Loutre 40000 2022-04-08 2022-06-17 2022-03-29 OPR-J350-FH-22 NOAA Ship Ferdinand Hassler (S250) Michael Gonsalves, CDR/NOAA MBES Kongsberg Maritime EM 2040 MBES Backscatter Kongsberg Maritime EM 2040 Atlantic Hydrographic Branch meters Any revisions to the Descriptive Report (DR) applied during office processing are shown in red italic text. The DR is maintained as a field unit product, therefore all information and recommendations within this report are considered preliminary unless otherwise noted. The final disposition of survey data is represented in the NOAA nautical chart products. All pertinent records for this survey are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via https://www.ncei.noaa.gov/. Products created during office processing were generated in NAD83 UTM 16N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. North American Datum 1983 Mean Lower Low Water VDatum Projected UTM 16 2022-12-06 CC0-1.0 (NOAA Field Units) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced by NOAA and are in the public domain within the United States. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). The survey area for H13626 was 40 NM East of Pass A Loutre in the northern Gulf of Mexico. Data were acquired to the survey limits in accordance with the requirements in the Project Instructions OPR-J350-FH-22 and the 2022 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in Figure 1. 29.30068916666667 88.41604952777779 29.290870416666667 88.16711986111112 H13626 sheet limits (in blue) overlaid onto Chart 11360. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626%20Survey%20Extents.PNG The 2010 Deepwater Horizon oil spill released over three million barrels of oil in the Gulf of Mexico, by far the largest offshore oil spill in US history. In 2016, the Deepwater Horizon Trustees reached a settlement for natural resource injuries caused by the Deepwater Horizon oil spill. The Deepwater Horizon Trustees documented a footprint of over 770 square nautical miles of injury to mesophotic and deep benthic habitat surrounding the wellhead and extending up the continental slope. Accurate high-resolution bathymetric and habitat maps and data on the abundance and distribution of mesophotic and deep benthic habitats are needed to guide restoration. Only a small portion of the mesophotic and deepwater habitats in the Gulf of Mexico have been surveyed, and with the collaboration and partnership of NOAA's Deepwater Horizon Program and the National Centers for Coastal and Ocean Science (NCCOS), the NOAA Ship Ferdinand R. Hassler collected bathymetry and backscatter data in the region. This work supports one of many projects selected by the Open Ocean Trustee Implementation Group to restore natural resources injured by the Deepwater Horizon oil spill. The data collected will be foundational for exploring mesophotic and deepwater habitats of the marine ecosystem by informing ground truthing locations for underwater camera footage, sediment cores, grab samples, ROV, and AUV work and for identifying future restoration sites. The data will also be used to update nautical charting products. The entire survey is adequate to supersede previous data. Data acquired in H13626 meet multibeam echo sounder (MBES) coverage requirements for complete coverage, as required by the HSSD. This includes crosslines, NOAA allowable uncertainty, and density requirements. Refer to the Data Acquisition and Processing Report (DAPR) for a complete description of data acquisition and processing systems, survey vessels, quality control procedures, and data processing methods. Additional information to supplement sounding and survey data, and any deviations from the DAPR are discussed in the following sections. Data acquisition efforts were led by crew of the Ferdinand Hassler with on-board support of NCCOS personnel and NOAA physical scientists. After acquisition, data were transferred off the ship and to NCCOS offices for additional multibeam and backscatter processing. A Final Feature File was created by the ships survey team and submitted separately from this report. Due to environmental considerations, the ship was excluded from working within certain portions of project OPR-J350-FH-22 during the evening hours. This resulted in the ship conducting a daily migration from the eastern side of the project to the western side of the project at sunset, then reversing the transit at sunrise. To remain productive, the ship acquired a single strip of data during each transit across some of the intermediate survey sheets (e.g. H13622, H13624, H13625). To simplify the file management, the sound velocity casts were concatenated across the entire project (rather than being strictly assigned to a single survey sheet). Due to the servicing of the ship's Moving Velocity Profiler (MVP), all data acquired between April 4 - 26 (DN094 - DN116) had the sound speed corrected via static CTD casts. In conjunction with the aforementioned transits, a CTD cast was taken at each sheet boundary. During processing, NCCOS followed procedures outlined in the Ferdinand Hassler DAPR and additional processing Standard Operating Procedures (SOP). Backscatter processing was completed using FMGT 7.10 software package. The raw (.all) data files were paired with post processed HDCS CARIS files resulting in a gsf file used to create the 2m intensity (-db) mosaic. Sensor characteristics and survey metadata within the .all and HDCS files are preserved in the gsf files. The intensity mosaic was normalized and exported as a floating point GeoTIFF. Final surfaces were analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. With the exception of the 4m surface (where 95% of nodes met uncertainty standards), 99% of nodes in the 8m and 16m surfaces meet NOAA Allowable Uncertainty and Data Density specification with grid nodes containing five or more soundings as required by HSSD Section 5.2.2.3 (Figures 2-7). Crosslines were collected in accordance with the NOAA HSSD, and are included as part of the finalized grids. H13626 4m grid allowable uncertainty statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_4m_MLLW_FInal.QAv6.tvu_qc.png H13626 4m grid data density statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_4m_MLLW_FInal.QAv6.density.png H13626 8m grid allowable uncertainty statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_8m_MLLW_FInal.QAv6.tvu_qc.png H13626 8m grid data density statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_8m_MLLW_FInal.QAv6.density.png H13626 16m grid allowable uncertainty statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_16m_MLLW_FInal.QAv6.tvu_qc.png H13626 16m grid data density statistics. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/grid_qa/H13626_MB_16m_MLLW_FInal.QAv6.density.png US3GC05M: Cape Saint George to Mississippi Passes 456394 60 2022-06-09 2022-06-09 H13626_MB_4m_MLLW_Final CARIS Raster Surface (CUBE) 4 60.9566 80.0 NOAA_4m Complete MBES H13626_MB_8m_MLLW_Final CARIS Raster Surface (CUBE) 8 72.0 160.0 NOAA_8m Complete MBES H13626_MB_16m_MLLW_Final CARIS Raster Surface (CUBE) 16 144.0 197.0 NOAA_16m Complete MBES H13626_MBAB_2m_S250_200kHz_1of1 MB Backscatter Mosaic 2 N/A Complete MBES Hassler_H13626_EM2040_Bathy_2m CARIS Raster Surface (CUBE) 2 52.2 212.7 NOAA_2m Complete MBES Four bathymetric and one backscatter surface were created for H13626 survey area. Three surfaces were created adhering to requirements of the HSSD, together these cover the survey area at 4m, 8m, and 16m resolutions (Figure 8). Surfaces include crosslines and are broken up by HSSD depth requirements. There are gaps in the coverage corresponding with a charted production platforms/oil derricks (Figure 9). NCCOS created 2m resolution bathymetry and backscatter (Figure 10) surfaces for the entire survey area. These surfaces include mainscheme lines only, crosslines were excluded. These will be used for additional spatial analysis by NCCOS. The 2m bathymetric surface is included only as a working CSAR file, it was not finalized in CARIS. Crosslines were collected, processed and compared in accordance with Section 5.2.4.2 of the HSSD for quality control. To evaluate crosslines, a surface generated via data strictly from mainscheme lines and a surface generated via data strictly from crosslines were created. From these two surfaces, a difference surface (mainscheme - crosslines = difference surface) was generated. Statistics show that the mean difference between depths derived from mainscheme data and crossline data was 0.01 meters and 95% of nodes falling within +/- 0.23 meters (Figure 11). For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards. In total, 99.5% of the depth differences between mainscheme and crossline data were within allowable NOAA uncertainties (Figure 12) Contours from the survey were generated and visually compared with the charted contours from the largest scale Electronic Navigation Chart (US3GC04M & US3GC05M). Referencing Figure 13, the charted 30, 40, 50 and 100-fathom contours (shown in black) have good agreement with the survey-derived contours (shown in blue); where any discrepancy can largely be dismissed as the result of chart generalization. Survey soundings were generated from an 8-meter single resolution CUBE surface in CARIS HIPS and compared with the soundings from the largest scale ENC using the CA Tools - SS vs. Chart comparison tool available in NOAA's Pydro Explorer suite. CA Tools will flag any surveyed sounding that is shoaler than what is expected from a chart-derived TIN surface - these could be potential Dangers to Navigation (DTON). In all cases, these flagged soundings are significantly deeper than even the deepest draft vessels, and do not represent a hazard to surface navigation. It is worth observing that surveys H13620, H13621, H13622, H13623 and H13624 have a disproportionately large number of flagged soundings. This is an artifact due to the fact that these surveys intersect large fish havens which do not contain charted soundings. While an immediate update to the chart is not warranted, the hydrographer recommends the addition of these shoaler soundings to the ENC. H13626 Coverage overview of combined 4m, 8m, and 16m resolution CUBE grids. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626%20Coverage%20Overview.PNG Data gaps associated with obstructions. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626%20Coverage%20Gaps.PNG Overview of backscatter data for H13626 at 2m resolution. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626%20Backscatter%20Overview.PNG H13626 Distribution of depth difference values (m) calculated between crossline and mainscheme grids. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626_no_XL_8m-H13626_XL_only_8m_depth_delta.png H13626 Crossline comparison distribution of nodes with an allowable error fraction. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626_no_XL_8m-H13626_XL_only_8m_fracAllowErr_Freq.png Comparison of charted vs. surveyed depths. Soundings in meters. file:///B:/OPR-J350-FH-22/Surveys/H13626/01_HDR/Reports/Descriptive_Report/SupportFiles/H13626_chart_compare.png No Horizontal and Vertical Control Report has been generated in association with OPR-J350-FH-22. ERS methods were used as the final means of reducing the survey to MLLW for submission. Vessel kinematic data were post-processed using Applanix POSPac MMS processing software and RTX positioning methods described in the DAPR. A Smoothed Best Estimate of Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS HIPS and SIPS. During real-time acquisition, all platforms received correctors from the Wide Area Augmentation System (WAAS) for increased accuracies similar to USCG DGPS stations. WAAS and SBETs were the sole methods of positioning for this survey as no DGPS stations were available for real-time horizontal control. As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed the attached survey data and reports. All field sheets, this Survey Summary Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch. The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Field Procedures Manual, Standing and Letter Instructions, and all HSD Technical Directives. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required with the exception of deficiencies noted in the Survey Summary Report. Michael Gonsalves, CDR/NOAA Chief of Party 2022-12-06 Karina Urquhart, LTJG/NOAA/NCCOS Sheet Manager 2022-12-06