OPR-O351-RA-21 Glacier Bay, Alaska Glacier Bay NOAA Ship Rainier (S221) H13401 3 Bartlett Cove Alaska United States 10000 2021 Olivia A. Hauser CDR/NOAA Navigable Area 2021-03-04 2021-03-20 2021-06-14 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter meters UTC Pacific Hydrographic Branch 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 8N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. 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). NOAA This survey is referred to as H13401, "Bartlett Cove" (sheet 3) within the Project Instructions. The assigned survey area encompassed an estimated 35 square nautical miles among the Beardslee Islands near the southern entrance to Glacier Bay National Park. 58.636195 136.04785 58.440261 135.844989 H13401 assigned survey area (Chart 17318). SupportFiles\H13401_Assigned_Area.jpg Survey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD. Glacier Bay in Southeast Alaska was covered by a single ice sheet as recently as the late 1700s. The tidewater glaciers that visitors see today are remnants of the calving and retreat of this glacial ice. In 2019, Glacier Bay National Park received approximately 675,000 visitors traveling by cruise ships, tour boats, charter boats and private vessels. Most of the glaciers within the bay are thinning and receding due to rapidly warming atmospheric temperatures and ocean water, exposing uncharted areas at the glacier faces. In addition, glacial till has altered the bathymetry in the fjords near the glaciers. While most of Glacier Bay was last surveyed in 2009, the southern portion was last surveyed prior to 2001. This survey focuses on several coves within Glacier Bay. Conducting a modern bathymetric survey in this area will provide critical data for the updating of National Ocean Service (NOS) nautical charting products and services to increase maritime safety in Glacier Bay. Data from this survey is intended to supersede all prior survey data in the common area. The entire survey is adequate to supersede previous data. All waters in survey area Complete Coverage (Refer to HSSD Section 5.2.2.3) A significant amount of multibeam echosounder coverage was acquired in H13401 to the inshore limit of hydrography, the Navigable Area Limit Line (NALL). The NALL is defined as the most seaward of the following: the surveyed 3.5 meter depth contour, the line defined by the distance seaward from the observed MHW line which is equivalent to 0.8 millimeters at chart scale (the assigned sheet limits closely reflect this) or the inshore limit of safe navigation. Areas where H13401 survey coverage reached neither 3.5 meters water depth, nor the assigned sheet limits, were due to the presence of hazardous rocks and/or thick kelp. The figures included below illustrate the areas in which the NALL was reached and not reached. The NALL was not reached continuously throughout the shore surrounding Flapjack Island, southern shores of Beartrack Cove, the western shores of an island directly south of Flapjack Island, and areas between Eider Island and Secret Bay. See figures below for more information. Additional MBES coverage was completed outside the southern-most edge of the assigned survey limits in an effort to locate a submerged park service instrument. No instrument was discovered but the additional coverage is included in the final surface. H13401 MBES coverage and assigned survey limits as black dashed lines (Chart 17318). SupportFiles\FinalCoverage.JPG Example of areas surrounding Flapjack Island and southern shores of Beartrack Cove where the 3.5-meter NALL was not reached. Red indicates areas where the 3.5-meter NALL was reached and the green dashed line indicates the assigned sheet limits. SupportFiles\A.4_NALL_Coverage.JPG 2801 0.0 177.67 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2802 0.0 212.82 0.0 0.0 0.0 0.0 0.0 15.37 0.0 2803 0.0 265.15 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2804 0.0 250.81 0.0 0.0 0.0 0.0 0.0 15.35 0.0 0.0 906.46 0.0 0.0 0.0 0.0 0.0 30.72 0.0 0.0 5 0 30 0 32.37 2021-03-20 2021-03-21 2021-03-22 2021-03-23 2021-03-24 2021-03-25 2021-03-26 2021-03-27 2021-03-28 2021-03-29 2021-03-30 2021-06-13 2021-06-14 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. 2801 8.8 1.1 2802 8.8 1.1 2803 8.8 1.1 2804 8.8 1.1 1701 7.62 0.47 1905 5.7 0.35 NOAA Ship RAINIER survey launch 2802. SupportFiles\2802.JPG All H13401 survey data were acquired by NOAA Ship RAINIER launches 2801, 2802, 2803 and 2804. These vessels acquired depth soundings, backscatter imagery and sound speed profiles. RAINIER Jetboat 2701 and RAINIER Skiff 1905 conducted limited shoreline feature verification. Positioning and Attitude System Applanix POS MV 320 v5 MBES Kongsberg Maritime EM 2040 Conductivity, Temperature, and Depth Sensor Sea-Bird Scientific SBE 19plus Sound Speed System Teledyne RESON SVP 70 RAINIER launches 2802 and 2804 acquired 30.72 linear nautical miles (3.4%) of MBES crosslines across all depth ranges, water masses and boat days that were operationally practical in order to evaluate the internal consistency of H13401 sonar data. Crossline analysis was performed using the Compare Grids function within Pydro Explorer on Caris variable-resolution surfaces of H13401 mainscheme only and crossline only data. 99.5% of grid nodes met allowable uncertainties as shown in the Pydro generated histograms below. H13401 crossline surface overlaid on mainscheme tracklines. SupportFiles\XL with mainscheme lines.JPG Pydro derived plot showing percentage-pass value of H13401 mainscheme to crossline data. SupportFiles\H13401_CUBE_2m_Mainscheme-H13401_CUBE_2m_XL_depth_delta.png Pydro derived plot showing absolute difference statistics of H13401 mainscheme to crossline data. SupportFiles\H13401_CUBE_2m_Mainscheme-H13401_CUBE_2m_XL_fracAllowErr_Freq.png ERS via VDATUM 0.0 0.13 2801,2802,2803,2804 3 0.05 Total Propagated Uncertainty (TPU) values for survey H13401 were derived from a combination of fixed values for equipment and vessel characteristics, as well as from field assigned values for sound speed uncertainties. Tidal uncertainty was provided in the Project Instructions for the NOAA vertical datum transformation model used for this survey. In addition to the usual a priori estimates of uncertainty, some real-time and post-processed uncertainty sources were also incorporated into the depth estimates of this survey. Real-time uncertainties for position, navigation, attitude and vessel motion data from Applanix POS MV were applied during acquisition and initially in post processing. However, the SBET and RMS files, which were generated using POSPac MMS software and applied in Caris HIPS to supersede POS MV data, have post-processed uncertainties associated with the GPS height and position. Uncertainty values of the submitted finalized grids were calculated in Caris using "Greater of the Two" of uncertainty and standard deviation (scaled to 95%). Grid QA within Pydro Tools (v.3.4.3) was used to analyze H13401 TVU compliance and multibeam (MBES) data density; histogram plots of the results are shown below. H13401 met HSSD requirements in over 99.5% of grid nodes and the submitted H13401 variable-resolution (VR) surface met HSSD density requirements. Pydro derived plot showing TVU compliance of H13401 finalized variable-resolution MBES data. SupportFiles\H13401_MB_VR_MLLW_FINAL.QAv6.tvu_qc.png Pydro derived histogram plot showing HSSD density compliance of H13401 finalized variable-resolution MBES data. SupportFiles\H13401_MB_VR_MLLW_FINAL.QAv6.density.png Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. None Exist There were no other factors that affected corrections to soundings. 120 sound speed profiles were acquired for this survey at discrete locations within the survey area at least once every four hours, when significant changes to surface sound speed were observed, or when moving survey operations to a new area. Sound speed data were acquired using Sea-Bird Scientific SBEplus profilers. All casts were concatenated into a master file and applied to H13401 MBES data using the "Nearest distance within Time" (4 hours) profile selection method. H13401 sound speed cast locations. SupportFiles\SVP_Cast_Locations.JPG All equipment and survey methods were used as detailed in the DAPR. All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR. Raw backscatter data were acquired as .ALL files logged during MBES operations and subsequently processed by RAINIER personnel. The .GSF files created during processing and backscatter mosaics per vessel and per frequency are delivered with this report. Backscatter processing procedures are described in the DAPR. Overview of H13401 backscatter mosaics. SupportFiles\BackscatterMosaics.JPG CARIS HIPS and SIPS 11.2.4 QPS Fledermaus Geocoder Tool Box (FMGT) 7.9.4 NOAA Profile (v2021). H13401_MB_VR_MLLW CARIS VR Surface (CUBE) Variable Resolution -2.23 251.19 NOAA_VR Complete MBES H13401_MB_VR_MLLW_Final CARIS VR Surface (CUBE) Variable Resolution -2.23 251.19 NOAA_VR Complete MBES Submitted H13401 surfaces were generated using NOAA recommended parameters for density-based (Ranges) Caris variable-resolution bathymetric grids. Four soundings were designated and submitted as DTONs. See DTON report in project correspondence attachment. Pydro QC Tools v.3.4.3 Flier Finder v8 program with default settings was used to identify sounding "fliers" in submitted H13401 surfaces. The program identified 12 fliers which, after examination, were determined to be false positives. Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying DAPR. Mean Lower Low Water ERS via VDATUM OPR-O351-FA-20_VDatum_100m_NAD83(2011)-MLLW_XGEOID16B.csar OPR-O351-FA-20_VDatum_100m_NAD83(2011)-MHW_XGEOID16B.csar North American Datum 1983 Projected UTM 8 Precise Positioning-Real time Extended (PP-RTX) processing methods were used in Applanix POSPac MMS (v8.5) software during post-processing horizontal correction of submitted H13401 MBES data. The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition. The majority of H13401's survey area is covered by ENC US4AK3DM with a small southern section covered by ENC US4AK36M. A cartographic discontinuity of up to 75 meters exists at the junction between the two ENCs, most noticeably near the western shore of Young Island. Positional offset between ENC US4AK3DM and US4AK36M. SupportFiles\ENC_Offset.jpg Shoreline Feature Verification Limited shoreline verification was conducted within the H13401 survey area using the Composite Source File (CSF) provided by NOAA HSD Operations Branch. Many features included in the CSF were inshore of the NALL. In the field, all assigned features that were deemed safe to approach, were addressed as required with S-57 attribution and recorded in the H13401 Final Feature File (FFF) to best represent features at chart scale. This file also includes any new features found in the field as well as recommendations to update, retain or delete assigned features. Features that were unsafe to approach or inshore of the NALL were attributed in the FFF as Not Addressed and the reason stated. US4AK3DM 80000 7 2018-09-20 2018-09-20 US4AK36M 80000 7 2018-10-22 2021-02-09 Four shoals were identified in this survey and submitted as DTONs for chart number 17318. See project correspondence for DTON report. Note C for the Beardslee Islands on RNC 17318 indicates a small craft advisory and recommends navigation only through local knowledge . This survey acquired complete coverage throughout the area and provides information to update areas included in the small craft advisory note. The "Shl to bare rep 1992" notation on RNC 17318 and ENC US4AK3DM was investigated during shoreline and visually determined to be present. Charted notation "Shl to bare rep 1992" was visually investigated and confirmed to be present during shoreline. SupportFiles\ShoalBareChartFeature.JPG At the direction of Glacier Bay National Park personnel, RAINIER was advised to keep an eye out for a sunken fishing vessel somewhere in the vicinity of northeast of Strawberry Island. A non-dangerous wreck was located, with a length of approximately 18m and a width of approximately 5m in roughly 67m of water. This wreck is believed to be the crabber "Westerly". From page 108 Navigating Troubled Waters: A History of Commercial Fishing in Glacier Bay, Alaska. On February 15, 1994, the steel-hulled, 72-foot Petersburg-based Westerly, which was preparing to set Tanner crab gear, reported that it was in danger of sinking northeast of Strawberry Island. There were gale-force winds from the north at the time. The three individuals aboard donned immersion suits and abandoned the vessel. They were almost immediately rescued by the vessel Northwyn, which was also fishing Tanner crab. The Westerly stayed afloat for approximately one hour, than sank east of Strawberry Island. Despite the severe weather, the cause of the sinking was not weather-related, but due to the sudden failure of a bulkhead in the main hold, which was filled with seawater to hold live crab. No attempt was made to salvage the Westerly. New non-dangerous wreck identified east of Sita Reef, north of Strawberry Island. SupportFiles\H13401_Wreck_Area.tif No maintained channels are located within the H13401 survey area. There are no designated anchorages, precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits. No Aids to navigation (ATONs) are located within the H13401 survey area. No Maritime Boundary Points were assigned for this survey. Five bottom samples were investigated for the survey; the results are included in the H13401 Final Feature File submitted with this report. No overhead features were observed within the H13401 survey area. No submarine features such as cables or pipelines were observed within the H13401 survey area. No drilling or production platforms are located within the H13401 survey area. No ferry routes or terminals exist for this survey. The U.S. National Park Service maintains a pier in Bartlett Cove where government vessels have priority. Tide rips are indicated for the Beardslee Islands entrance on chart 17318. Complete bottom coverage was acquired throughout this area and confirms steep changes in sea floor depth and numerous deep pools. Confused waves and tide rips were observed during the survey between Strawberry Island and Young Island, especially at maximum ebb and flood tidal currents. Multibeam sea floor coverage at the Beardslee Islands entrance where tide rips were observed during the survey. SupportFiles\TideRips.JPG No present or planned construction or dredging exist within the survey limits. No new surveys or further investigations are recommended for this area. A larger scale ENC would allow for safe navigation through the Beardslee Islands complex. 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 Descriptive 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, 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 Descriptive Report. Olivia A. Hauser, CDR/NOAA Chief of Party 2021-07-23 Matthew B. Sharr, LT/NOAA Field Operations Officer 2021-07-23 James B. Jacobson Chief Survey Technician 2021-07-23 Alice B. Beittel, ENS/NOAA Sheet Manager 2021-07-23