Metadata: Identification_Information: Citation: Citation_Information: Originator: Amy C. Foxgrover Originator: Theresa A. Fregoso Originator: Bruce E. Jaffe Publication_Date: 20241004 Title: South San Francisco Bay bathymetric change: 1858 to 2005 Geospatial_Data_Presentation_Form: GeoTIFF Series_Information: Series_Name: data release Issue_Identification: doi:10.5066/P13H35QB Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA Publisher: U.S. Geological Survey Online_Linkage: doi:10.5066/P13H35QB Online_Linkage: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Larger_Work_Citation: Citation_Information: Originator: Amy C. Foxgrover Originator: Theresa A. Fregoso Originator: Bruce E. Jaffe Publication_Date: 2024 Title: Historical bathymetry and bathymetric change within San Francisco Bay, California: 1855 to 2005 Series_Information: Series_Name: data release Issue_Identification: doi:10.5066/P13H35QB Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested Citation: Foxgrover, A.C., Fregoso, T.A., and Jaffe, B.E., 2024, Historical bathymetry and bathymetric change within San Francisco Bay, California: 1855 to 2005: U.S. Geological Survey data release, https://doi.org/10.5066/P13H35QB. Online_Linkage: doi:10.5066/P13H35QB Online_Linkage: https://www.sciencebase.gov/catalog/item/663ea8fdd34eaf9729f7b46d Description: Abstract: This data release provides a series of five bathymetric change grids generated from historical bathymetric surveys collected in south San Francisco Bay, CA from the 1858 to 2005. The National Ocean Service (NOS) and its predecessor, the United States Coast and Geodetic Survey, collected hydrographic surveys in 1858, 1898, 1931, 1956, and 1983 plus Sea Surveyor, Inc. collected a survey in 2005. Surface modeling software was used to generate bathymetric DEMs of each of these surveys. The bathymetric DEMs were then adjusted to account for gridding interpolation bias, changes in sea level through time, and ground subsidence that occurred in the Santa Clara Valley and lower South Bay from the 1930s to 1960s due to groundwater extraction. The adjusted DEMs for consecutive surveys were then differenced to reveal the amount of sediment erosion and deposition and changes from human activities (e.g., dredging and oyster shell mining) that occurred through time. These bathymetric change grids are provided here in GeoTIFF format with a horizontal resolution of 50 meters and can be used to quantify net sediment volume change and rates of change throughout the bay. Purpose: Analysis of historical bathymetric surveys enables us to reconstruct the surface of the bay floor through time and quantify spatial and temporal changes in deposition, erosion, and bathymetry over decadal timescales. These data provide insight on changes to San Francisco Bay in response to natural processes as well as anthropogenic activities and can inform numerous studies and applications such as sediment management practices, restoration projects, regional adaptation plans, contaminant transport research, and sea-level rise studies. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems (GIS) or other software to identify changes in the depth of the bay floor through time. These data are not intended to be used for navigational purposes. Supplemental_Information: Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1858 Ending_Date: 2005 Currentness_Reference: ground condition at time data were collected Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -122.392772 East_Bounding_Coordinate: -121.970645 North_Bounding_Coordinate: 37.762968 South_Bounding_Coordinate: 37.416934 Keywords: Theme: Theme_Keyword_Thesaurus: The National Map Collection Thesaurus Theme_Keyword: Digital Elevation Model (DEM) Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: bathymetry Theme_Keyword: topography Theme_Keyword: geographic information systems Theme_Keyword: geospatial datasets Theme_Keyword: GPS measurement Theme_Keyword: digital elevation models Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Bathymetry and Elevation Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: geographic information systems (GIS) Theme_Keyword: single-beam echo sounder Theme_Keyword: topographic mapping Theme_Keyword: Global Positioning System (GPS) observations Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: elevation Theme_Keyword: inlandWaters Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:667603ffd34e3cf50fef28e8 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: San Francisco Bay Place_Keyword: San Pablo Bay Place_Keyword: Suisun Bay Place: Place_Keyword_Thesaurus: None Place_Keyword: Central San Francisco Bay Place_Keyword: South San Francisco Bay Access_Constraints: No access constraints 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. Please recognize and acknowledge the U.S. Geological Survey 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_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator 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 Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_map_1858_1898.png&allowOpen=true Browse_Graphic_File_Description: Sample map of South Bay bathymetric change from 1858 to 1898. Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: Microsoft Version 6.2 (Build 9200); Esri ArcGIS 10.8.1.14362(Build 9270) Service Pack N/A (Build N/A) Cross_Reference: Citation_Information: Originator: Amy C. Foxgrover Originator: Shawn A. Higgins Originator: Melissa K. Ingraca Originator: Bruce E. Jaffe Originator: Richard E. Smith Publication_Date: 2004 Title: Deposition, erosion, and bathymetric change in South San Francisco Bay: 1858-1983 Other_Citation_Details: Foxgrover, A.C., Higgins, S.A., Ingraca, M.K., Jaffe, B.E., and Smith, R.E., 2004, Deposition, erosion, and bathymetric change in South San Francisco Bay 1858-1983: U.S. Geological Survey Open-File Report 2004-1192, 25 p., https://doi.org/10.3133/ofr20041192. Online_Linkage: https://doi.org/10.3133/ofr20041192 Cross_Reference: Citation_Information: Originator: Amy C. Foxgrover Originator: Bruce E. Jaffe Originator: Gerald T. Hovis Originator: Craig A. Martin Originator: James R. Hubbard Originator: Manoj R. Samant Originator: Steve M. Sullivan Publication_Date: 2007 Title: 2005 hydrographic survey of south San Francisco Bay, California Other_Citation_Details: Foxgrover, A.C., Jaffe, B.E., Hovis, G.T., Martin, C.A., Hubbard, J.R., Samant, M.R., and Sullivan, S.M., 2007, 2005 Hydrographic survey of South San Francisco Bay, California: U.S. Geological Survey Open-File Report 2007-1169, 99 p., https://doi.org/10.3133/ofr20071169. Online_Linkage: https://doi.org/10.3133/ofr20071169 Cross_Reference: Citation_Information: Originator: Bruce E. Jaffe Originator: Amy C. Foxgrover Publication_Date: 2006 Title: Sediment deposition and erosion in South San Francisco Bay, California from 1956 to 2005 Other_Citation_Details: Jaffe, B.E., and Foxgrover, A.C., 2006, Sediment deposition and erosion in South San Francisco Bay, California from 1956 to 2005: U.S. Geological Survey Open-File Report 2006-1287, 24 p., https://pubs.usgs.gov/of/2006/1287. Online_Linkage: https://pubs.usgs.gov/of/2006/1287 Cross_Reference: Citation_Information: Originator: International Hydrographic Organization (IHO) Publication_Date: 2022 Title: IHO standards for hydrographic surveys (6th ed.) Other_Citation_Details: reference on hydrographic survey standards provided for added interest to users of these data Online_Linkage: https://iho.int/uploads/user/pubs/standards/s-44/S-44_Edition_6.1.0.pdf Cross_Reference: Citation_Information: Originator: Environmental Systems Research Institute, Inc (Esri) Publication_Date: 2024 Title: Topo to Raster help page Online_Linkage: https://desktop.arcgis.com/en/arcmap/latest/tools/3d-analyst-toolbox/topo-to-raster.htm Cross_Reference: Citation_Information: Originator: J. F. Poland Originator: R. L. Ireland Publication_Date: 1988 Title: Land Subsidence in the Santa Clara Valley, California, as of 1982 Other_Citation_Details: Poland, J.F., and Ireland, R.L. 1988, Land Subsidence in the Santa Clara Valley, California, as of 1982: U.S. Geological Survey Professional Paper 497-F, 61 p. https://pubs.usgs.gov/pp/0497f/report.pdf. Online_Linkage: https://pubs.usgs.gov/pp/0497f/report.pdf Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted. Logical_Consistency_Report: No formal logical consistency tests were conducted. Completeness_Report: Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Data are as accurate as source data used. No further tests were conducted, and no claims are made to positional accuracy. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Data are as accurate as source data used. No further tests were conducted, and no claims are made to vertical accuracy. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 2024 Title: NOAA National Centers for Environmental Information (NCEI) Bathymetric Data Viewer website Geospatial_Data_Presentation_Form: xyz, tif Publication_Information: Publication_Place: online Publisher: NOAA / NESDIS / NCEI / Maps / Seafloor Mapping Online_Linkage: https://www.ncei.noaa.gov/maps/bathymetry/ Type_of_Source_Media: Digital Resources Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1857 Ending_Date: 1985 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: NOAAbathy Source_Contribution: NOAA NOS single-beam surveys. 1850s to 1920s surveys available as images of NOS smooth sheets, 1930s to 1980s as digital sounding data. Source_Information: Source_Citation: Citation_Information: Originator: Amy C. Foxgrover Originator: Bruce E. Jaffe Originator: Gerald T. Hovis Originator: Craig A. Martin Originator: James R. Hubbard Originator: Manoj R. Samant Originator: Steve M. Sullivan Publication_Date: 2007 Title: 2005 Hydrographic Survey of South San Francisco Bay, California Geospatial_Data_Presentation_Form: xyz Publication_Information: Publication_Place: online Publisher: US Geological Survey Online_Linkage: https://pubs.usgs.gov/of/2007/1169/ Type_of_Source_Media: Digital Resources Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20050110 Ending_Date: 20050405 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: 2005bathy Source_Contribution: 2005 single-beam survey conducted by Sea Surveyor, Inc. Source_Information: Source_Citation: Citation_Information: Originator: National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 2024 Title: NOAA Shoreline Data Explorer website Geospatial_Data_Presentation_Form: Raster Digital Dataset Publication_Information: Publication_Place: online Publisher: NOAA / NOS Online_Linkage: https://nsde.ngs.noaa.gov/ Type_of_Source_Media: Digital Resources Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1850 Ending_Date: 1985 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: NOSshore Source_Contribution: NOS Topographic Sheets (T-sheets) to extract mean high water (MHW) shorelines used as DEM extent boundary. Source_Information: Source_Citation: Citation_Information: Originator: San Francisco Estuary Institute Publication_Date: 1998 Title: San Francisco Estuary Institute EcoAtlas Geospatial_Data_Presentation_Form: shapefile Publication_Information: Publication_Place: compact disc Publisher: SFEI Type_of_Source_Media: Digital Resources Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1850 Ending_Date: 1998 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: SFEIshore Source_Contribution: Historical and modern baylands GIS shapefiles used to supplement shorelines extracted from T-sheets, as needed. Process_Step: Process_Description: All processes and methods used for developing the 1858, 1898, 1931, 1956, 1983 bathymetric DEMs are outlined in Foxgrover and others (2004); please refer to that for more information beyond the general overview summary provided in this document Process_Date: 2004 Process_Step: Process_Description: All processes and methods used for developing the 2005 bathymetric DEM are outlined in Foxgrover and others (2007); Jaffe and Foxgrover (2006); please refer to these for more information beyond the general overview summary provided in this document Source_Used_Citation_Abbreviation: 2005bathy Process_Date: 2006 Process_Step: Process_Description: Hydrographic sounding data downloaded for all time periods. Pre-1930s surveys were obtained as images of hydrographic sheets (H-sheets) that were then geoferenced to NAD83 and the soundings manually digitized. Post-1930 soundings were downloaded in digital format (NOAA, 2024). The 2005 soundings were downloaded in digital format from Jaffe and Foxgrover (2006). This study area is covered by multiple, smaller hydrographic surveys that were generally conducted over the span of one to three years. The year displayed with the DEMs provided is the year in which the majority of the South Bay was surveyed. However, the compilation of surveys covering the entire study area can span many years and end users are encouraged to view the original H-sheets and descriptive reports provided by NOAA (2024) for additional details. Source_Used_Citation_Abbreviation: NOAAbathy Source_Used_Citation_Abbreviation: 2005bathy Process_Date: 2005 Source_Produced_Citation_Abbreviation: soundings and contours Process_Step: Process_Description: Shorelines were digitized from T-sheets and assigned a spatially variable elevation value of MHW derived from nearby tide stations, ranging from 1.83 m in the north, to 2.8 m in the southernmost extent of the study area (Foxgrover and others, 2004). The 1858 and 2005 shorelines were modified base upon EcoAtlas data (San Francisco Estuary Institute, 1998). Source_Used_Citation_Abbreviation: NOSshore Source_Used_Citation_Abbreviation: SFEIshore Process_Date: 2005 Source_Produced_Citation_Abbreviation: shorelines Process_Step: Process_Description: Bathymetric contours were digitized from H-sheets or hand drawn as needed to help define the general morphology of the bay floor and constrain the gridding algorithm. To ensure realistic nearshore morphology in areas where soundings were not collected within close proximity to the shoreline, an additional contour was added parallel to the shoreline, 20 m within the bay and assigned an approximate elevation of mean tide level (MTL). Supplementary contours were manually added to the 1850's tidal flats where the original sounding values have been omitted from the H-sheets. Source_Used_Citation_Abbreviation: NOAAbathy Source_Used_Citation_Abbreviation: 2005bathy Source_Used_Citation_Abbreviation: NOSshore Process_Date: 2005 Source_Produced_Citation_Abbreviation: contours Process_Step: Process_Description: For each time period, point soundings were combined with bathymetric contours and shoreline shapefiles and interpolated into continuous surface models using ArcInfo's TopoGrid module (now Topo To Raster, Esri, 2024). The 2005 GeoTIFF has a horizontal resolution of 25 m and all other time periods, a resolution of 50 m. The 2005 data was resampled to 50 m prior to generating bathymetric change grids. Bathymetry in tributary channels less than 3-cells wide were excluded because they could not be accurately modeled at the given resolution. Z-values are in meters relative to the MLLW tidal epoch referenced at the time of survey collection. Source_Used_Citation_Abbreviation: NOAAbathy Source_Used_Citation_Abbreviation: 2005bathy Source_Used_Citation_Abbreviation: shorelines Process_Date: 2005 Source_Produced_Citation_Abbreviation: TopoGrid DEMs Process_Step: Process_Description: An estimate of grid interpolation bias was estimated for each time period by comparing the value of each individual sounding to the cell value of the bathymetric grid at that specific location. Each bathymetric DEM was then adjusted to correct for interpolation bias by deepening the raster surface by the mean values presented in Table 6 of Foxgrover and others (2004). The 2005 survey has and interpolation bias of 0, so no correction was applied. Note that the grid bias values reported in Foxgrover and others (2004) were only included as part of the uncertainty assessment and those corrections were not incorporated into the volume change calculations in that same report. However, for consistency with other San Francisco Bay subembayments in this data release, grid bias corrections have been applied to the GeoTIFFs provided here. Source_Used_Citation_Abbreviation: TopoGrid DEMs Process_Date: 2024 Source_Produced_Citation_Abbreviation: Bias ADJ DEMs Process_Step: Process_Description: Prior to generating bathymetric change DEMs for the 1931 to 1956 and 1956 to 1983 time periods, it was necessary to account for land subsidence that occurred within the southern extent of south San Francisco Bay as a result of excessive groundwater withdrawal from 1934 to 1967. Without correcting for subsidence, our grids of deposition and erosion would erroneously overestimate erosion during these time periods. The degree and spatial extent of subsidence documented in Poland and Ireland (1988) was applied to the 1931 to 1956 and 1956 to 1983 change grids following the methodology presented in Foxgrover and others (2004). Source_Used_Citation_Abbreviation: TopoGrid DEMs Process_Date: 2024 Source_Produced_Citation_Abbreviation: Subside ADJ DEMs Process_Step: Process_Description: The last step, prior to generating change grids, was to adjust all of the DEMs to a common vertical datum to account for changing survey datums associated with fluctuations in sea level over the 147-year span of the surveys. All surveys were adjusted to the same tidal epoch as the 2005 survey, the 1983-2001 tidal epoch, by adjusting the 1858 survey by -15.8 cm, the 1898 survey by -5.5 cm, the 1931 by -10.3, the 1956 by -6.7 cm and the 1983 survey by -1.8 cm. A negative adjustment (or a deepening of bathymetry) accounts for an increase in the height of the reference tidal datum over time. Neglecting this adjustment, would make the later survey appear deeper than an identical sounding at the same location from the earlier survey, thereby falsely exaggerating the impression of erosion over time. Source_Used_Citation_Abbreviation: TopoGrid DEMs Process_Date: 2024 Source_Produced_Citation_Abbreviation: MLLW ADJ DEMs Process_Step: Process_Description: Grids of sediment deposition and erosion amounts between consecutive time periods were generated by taking the above, adjusted DEMs and subtracting latter DEM from the earlier DEM. Z-values are in meters, and positive values represent sediment deposition and negative, sediment erosion. Source_Used_Citation_Abbreviation: MLLW ADJ DEMs Process_Date: 2024 Source_Produced_Citation_Abbreviation: Change DEM Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: pixel Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 10 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -123.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 50 Ordinate_Resolution: 50 Planar_Distance_Units: Meter Geodetic_Model: Horizontal_Datum_Name: D North American 1983 Ellipsoid_Name: GRS_1980 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: N/A, relative vertical change Altitude_Resolution: 0.01 Altitude_Distance_Units: meters Altitude_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: floating point Entity_Type_Definition: GeoTIFF of bathymetric change for the specified time period. Z-value in meters, positive values represent sediment deposition and negative represent sediment erosion. Cells with values of -3.4028231e+38 indicate No Data. Entity_Type_Definition_Source: Producer defined Attribute: Attribute_Label: Value Attribute_Definition: Bathymetric change (m) Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -8.97 Range_Domain_Maximum: 7.98 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 0.01 Overview_Description: Entity_and_Attribute_Overview: GeoTIFF of bathymetric change for the specified time period. Z-value in meters, positive values represent sediment deposition and negative represent sediment erosion. Cells with values of -3.4028231e+38 indicate No Data. Entity_and_Attribute_Detail_Citation: The entity and attribute information were generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Country: US Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: Files (SB_chg_1858_1898_m.zip, SB_chg_1898_1931_m.zip, SB_chg_1931_1956_m.zip, SB_chg_1956_1983_m.zip, SB_chg_1983_2005_m.zip) contain bathymetric change grids in GeoTIFF format for the time period indicated. 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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTIFF of the 1858 to 1898 bathymetric change grid and associated TIFF world file (.tfw) File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 0.3 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_1858_1898_m.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Network_Resource_Name: https://doi.org/10.5066/P13H35QB Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of bathymetry data. The second link points to a landing page for bathymetric change grids derived from these DEMs. The third link points to the landing page for the entire San Francisco Bay data series. Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTIFF of the 1898 to 1931 bathymetric change grid and associated TIFF world file (.tfw) File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 0.3 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_1898_1931_m.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Network_Resource_Name: https://doi.org/10.5066/P13H35QB Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of bathymetry data. The second link points to a landing page for bathymetric change grids derived from these DEMs. The third link points to the landing page for the entire San Francisco Bay data series. Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTIFF of the 1931 to 1956 bathymetric change grid and associated TIFF world file (.tfw) File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 0.3 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_1931_1956_m.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Network_Resource_Name: https://doi.org/10.5066/P13H35QB Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of bathymetry data. The second link points to a landing page for bathymetric change grids derived from these DEMs. The third link points to the landing page for the entire San Francisco Bay data series. Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTIFF of the 1956 to 1983 bathymetric change grid and associated TIFF world file (.tfw) File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 0.3 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_1956_1983_m.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Network_Resource_Name: https://doi.org/10.5066/P13H35QB Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of bathymetry data. The second link points to a landing page for bathymetric change grids derived from these DEMs. The third link points to the landing page for the entire San Francisco Bay data series. Digital_Form: Digital_Transfer_Information: Format_Name: GeoTIFF Format_Version_Number: ArcGIS 10.8.1 Format_Information_Content: Zip file contains a GeoTIFF of the 1983 to 2005 bathymetric change grid and associated TIFF world file (.tfw) File_Decompression_Technique: Data can be unpacked using WinZip, or other zip decompression software. Transfer_Size: 0.4 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/667603ffd34e3cf50fef28e8?name=SB_chg_1983_2005_m.zip Network_Resource_Name: https://www.sciencebase.gov/catalog/item/667603ffd34e3cf50fef28e8 Network_Resource_Name: https://doi.org/10.5066/P13H35QB Access_Instructions: Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of bathymetry data. The second link points to a landing page for bathymetric change grids derived from these DEMs. The third link points to the landing page for the entire San Francisco Bay data series. Fees: None Technical_Prerequisites: These data can be viewed with GIS software such as ArcGIS, QGIS, or Global Mapper. Metadata_Reference_Information: Metadata_Date: 20241004 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator 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 Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998