Metadata: Identification_Information: Citation: Citation_Information: Originator: Peter Dartnell Originator: Daniel S. Brothers Originator: Brian Sherrod Originator: Gerald A. Hatcher Originator: Daniel C. Powers Originator: Jenna C. Hill Originator: Jackson E. Currie Originator: Peter Dal Ferro Publication_Date: 20250917 Title: Bathymetry data for Lake Sammamish, Washington collected during USGS field activity 2021-656-FA Geospatial_Data_Presentation_Form: GeoTIFF Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P1YKDHGC Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P1YKDHGC Larger_Work_Citation: Citation_Information: Originator: Peter Dartnell Originator: Daniel S. Brothers Originator: Brian Sherrod Originator: Gerald A. Hatcher Originator: Daniel C. Powers Originator: Jenna C. Hill Originator: Jackson E. Currie Originator: Peter Dal Ferro Publication_Date: 2025 Title: Bathymetry and acoustic-backscatter data for Lake Sammamish, Washington collected during USGS field activity 2021-656-FA Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P1YKDHGC Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, CA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested Citation: Dartnell, P., Brothers, D.S., Sherrod, B., Hatcher, G.A., Powers, D.C., Hill, J.C., Currie, J.E., Dal Ferro, P., 2025, Bathymetry and acoustic-backscatter data for Sammamish Lake, Washington collected during USGS field activity 2021-656-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P1YKDHGC. Online_Linkage: https://doi.org/10.5066/P1YKDHGC Description: Abstract: Here November 2021 2-m resolution bathymetry data of Lake Sammamish, Washington are provided for the entire lake. Data were collected and processed by the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number 2021-656-FA. Data are provided as a GeoTIFF image. Purpose: The Pacific Northwest is home to numerous faults that cut through the surrounding crust including the Seattle fault. Over time, frictional stresses accumulate along these faults, building slowly until they exceed the fault's strength, resulting in an earthquake. Evidence of these earthquakes may be found in Pacific Northwest lakes. Past underwater landslides caused by the earthquakes should be well preserved in these relatively undisturbed environments. The lake floor of Lake Sammamish in the Pacific Northwest was mapped to find such evidence of past earthquakes. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify bathymetric features. These data are not intended to be used for navigation. Supplemental_Information: Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-656-FA 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: 20211108 Ending_Date: 20211112 Currentness_Reference: ground condition at time data were collected. Status: Progress: Complete Maintenance_and_Update_Frequency: None Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -122.200 East_Bounding_Coordinate: -121.966 North_Bounding_Coordinate: 47.652 South_Bounding_Coordinate: 47.557 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:a3e9343c-afd7-415f-982e-8dad99644dc8 Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme_Keyword: elevation Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: bathymetry Theme_Keyword: bathymetry measurement Theme_Keyword: lakebed characteristics Theme_Keyword: geospatial datasets Theme_Keyword: marine geophysics Theme_Keyword: sonar methods 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: field observation 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 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Lake Sammamish Place_Keyword: State of Washington 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 originators 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: LakeSammamish_USGS_2021_2m_bathymetry_UTM10_NAD83_NAVD88_QV.jpg Browse_Graphic_File_Description: Preview image of USGS 2021 Lake Sammamish bathymetry Browse_Graphic_File_Type: JPEG Native_Data_Set_Environment: SonarWiz(ver. 6) and ArcMap (ver. 10.3.1) on a Windows 10 computer. Cross_Reference: Citation_Information: Originator: Peter Dartnell Originator: Daniel S. Brothers Originator: Brian Sherrod Originator: Gerald A. Hatcher Originator: Daniel C. Powers Originator: Jenna C. Hill Publication_Date: 2025 Title: Bathymetric and acoustic-backscatter mapping of Lake Sammamish, Washington, during USGS field activity 2021-656-FA Other_Citation_Details: Dartnell, P., Brothers, D.S., Sherrod, B., Hatcher, G.A., Powers, D.C., and Hill, J.C., 2025, Bathymetric and acoustic-backscatter mapping of Lake Sammamish, Washington, during USGS field activity 2021-656-FA: U.S. Geological Survey Data Report 1207, https://doi.org/10.3133/dr1207 Online_Linkage: https://doi.org/10.3133/dr1207 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The SWATHPlus sonar system (234 kHz) depth standard deviation varies with horizontal range and water depth. The system has an estimated depth standard deviation ranging from about 0.1 m to 0.7 m over a horizontal range of 0 to greater than 100 m (https://doi.org/10.3390/rs14092011). Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations. Refer to data report, Dartnell and others, 2024, for other accuracy assessments. Logical_Consistency_Report: No formal logical accuracy tests were conducted Completeness_Report: Dataset 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: The Applanix POS-MV post-processed horizontal positional accuracy is about 0.1 m with roll and pitch accuracies of about 0.02 degrees (https://www.applanix.com/downloads/products/specs/posmv/POS-MV-WaveMaster-II.pdf). Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The Applanix POS-MV post-processed vertical positional accuracy is about 0.2 m (https://www.applanix.com/downloads/products/specs/posmv/POS-MV-WaveMaster-II.pdf). Accuracies of final products may be lower due to total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations. Lineage: Process_Step: Process_Description: The data were collected with a SWATHplus-M 234-kHz interferometric side-scan sonar system pole-mounted on the U.S. Geological Survey (USGS) R/V San Lorenzo. During the mapping mission, an Applanix POS-MV (Position and Orientation System for Marine Vessels) was used to position the vessel during data collection, and it also accounted for vessel motion such as heave, pitch, and roll. The POS-MV also recorded position and vessel motion parameters for later post-processing. Sound-velocity profiles were collected throughout the survey days with a Castaway sound velocimeter. Post-processed POS-MV Smoothed Best Estimate of Trajectory (SBET) files were merged with the survey line files using BathySwath software and then the line files were imported into SonarWiz software. Soundings were cleaned for obvious errors and gridded into a 2-m base surface. The base surface was exported as an Erdas Imagine file in UTM-10, WGS-84 coordinates vertically referenced to the WGS84 ellipsoid. The data were transformed from WGS-84 to NAD-83 horizontal coordinates using ArcGIS Pro ArcTool raster projection command WGS_1984_(ITRF08)_To_NAD_1983_2011. NOAA's on-line VDATUM transformation tool states there is a +23.688m difference between WGS-84 and NAVD-88 elevations (vertical uncertainty of 0.06m) at a point in the center of the lake. A value of 23.688m was added to the original bathymetry grid to transform from WGS-84 elevations to NAVD-88 elevations. The NAVD-88 bathymetry grid was then exported as a GeoTIFF file in UTM zone 10, NAD-83(2011) coordinates, relative to NAVD88. Process_Date: 2022 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 5380 Column_Count: 8710 Vertical_Count: 1 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: -123.00000 Latitude_of_Projection_Origin: 0.00000 False_Easting: 500000.0 False_Northing: 0.00 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 1.0 Ordinate_Resolution: 1.0 Planar_Distance_Units: Meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983, 2011 realization (NAD83(2011)) Ellipsoid_Name: GRS80 Semi-major_Axis: 6378137.00 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North America Vertical Datum 1988 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: value Entity_Type_Definition: elevation in meters relative to NAVD-88 Entity_Type_Definition_Source: Producer defined Overview_Description: Entity_and_Attribute_Overview: The complete 2-m resolution grid "LakeSammamish_USGS_2021_2m_bathymetry_UTM10_NAD83_NAVD88.tif" was originally archived as a TIFF image with the following attributes. >Cell size = 2.0 >Number of rows = 5380 >Number of columns = 8710 > >Data type = floating point > >Boundary >Xmin = 560211 >Xmax = 577634 >Ymin = 5267349 >Ymax = 5278111 > >Statistics >Minimum value = -25.03 >Maximum value = 9.86 >Mean = -10.76 >Standard deviation = 5.96 > >Coordinate system description >Projection: UTM >Zone: 10 >Datum: NAD83(2011) >Vertical Reference: NAVD88 >Units: meter 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 Resource_Description: These data are available in GeoTIFF format, including a tif world file (.tfw), accompanied by CSDGM FGDC-compliant 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 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: ArcMap (version 10.3.1) Format_Information_Content: Downloadable zip file contains the TIFF (.tif) version of the bathymetry data and a projection file (.tfw). File_Decompression_Technique: WinZip Transfer_Size: 14.4 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5066/P1YKDHGC Access_Instructions: Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the sonar data section. Fees: None. Technical_Prerequisites: The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing a GeoTIFF file. Metadata_Reference_Information: Metadata_Date: 20250917 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