Identification_Information: Citation: Citation_Information: Originator: Labay, Keith A. Originator: Haeussler, Peter J. Publication_Date: 2008 Title: Combined high-resolution LIDAR topography and multibeam bathymetry for northern Resurrection Bay, Seward, Alaska Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: DS 374 Online_Linkage: http://pubs.usgs.gov/ds/374 Description: Abstract: We created a new Digital Elevation Model using the best available high-resolution topography and multibeam bathymetry surrounding the area of Seward, Alaska. Datasets of (1) LIDAR topography collected for the Kenai Watershed Forum, (2) Seward harbor soundings from the Army Corp of Engineers, (3) and NOAA multibeam bathymetry contributed to the final merged product. These datasets were placed into a common coordinate system, horizontal datum, vertical datum, and data format prior to being merged together. The projected coordinate system of Universal Transverse Mercator Zone 6 North American Datum of 1927 was used for the horizontal coordinates. Z-values in meters were referenced to the tidal datum of Mean High Water. Gaps between the datasets were interpolated to create the final seamless five-meter grid covering the area of interest around Seward, Alaska. Purpose: This digital elevation model (DEM) was created for studying submarine landslides and tsunamis produced by the M9.2 1964 earthquake at Seward, Alaska, and for developing computer models of tsunami inundation risks as part of the National Tsunami Hazards Mitigation Program. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2001 Ending_Date: 2007 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -149.465478 East_Bounding_Coordinate: -149.312773 North_Bounding_Coordinate: 60.156298 South_Bounding_Coordinate: 60.057664 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Bathymetry Theme_Keyword: Elevation Theme_Keyword: Topography Theme_Keyword: LIDAR Theme_Keyword: DEM Place: Place_Keyword_Thesaurus: Geographic names information system (GNIS) Place_Keyword: Alaska Place_Keyword: Kenai Peninsula Place_Keyword: Resurrection Bay Place_Keyword: Seward Access_Constraints: None Use_Constraints: NOT TO BE USED FOR NAVIGATION Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from this data. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Keith A. Labay Contact_Position: GIS Specialist Contact_Address: Address_Type: mailing and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508-4667 Country: U.S.A. Contact_Voice_Telephone: 907-786-7410 Contact_Electronic_Mail_Address: klabay@usgs.gov Native_Data_Set_Environment: Data set was created using ESRI ArcGIS 9.2 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: See Vertical Accuracy Report Logical_Consistency_Report: The Z-values in this DEM are a composite of 3 major sources. Completeness_Report: This DEM has been visually inspected for completeness. NODATA areas exist. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal accuracy of this DEM has not been tested. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The vertical accuracy of this DEM has not been tested. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: NOAA National Ocean Service Publication_Date: 2001 Title: National Ocean Service Office of Coast Survey Hydrographic Survey Data Geospatial_Data_Presentation_Form: ASCII YXZ data Online_Linkage: http://www.ngdc.noaa.gov/nndc/struts/results?op_0=l&v_0=H11072&t=101523&s=3&d=5&d=10&d=11&d=12&d=13&d=14&d=15&d=16&d=17&d=18&d=19&no_data=suppress Source_Scale_Denominator: 10000 Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20010831 Ending_Date: 20010921 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: multibeam bathymetry Source_Contribution: Bathymetry of northern Resurrection Bay. Source_Information: Source_Citation: Citation_Information: Originator: Kenai Watershed Forum Publication_Date: unpublished Title: none Geospatial_Data_Presentation_Form: raster digital data Type_of_Source_Media: DVD-ROM Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20060106 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Seward LIDAR Source_Contribution: LIDAR topography of Seward, Alaska. Source_Information: Source_Citation: Citation_Information: Originator: Army Corps of Engineers Publication_Date: unpublished Title: none Geospatial_Data_Presentation_Form: ASCII XYZ data Type_of_Source_Media: text file Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20060428 Ending_Date: 20060504 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Seward harbor Source_Contribution: Soundings of the Seward, Alaska harbor. Process_Step: Process_Description: The Seward LIDAR data was obtained from the Kenai Watershed Forum as an ARC/INFO grid. Projection of the grid was Alaska State Plane FIPS 5004 NAD83. Z-values were in feet. The vertical datum of the Z-values was NAVD88. This grid was then reprojected into UTM Zone 6 NAD27. Z-values were converted to meters instead of feet. From the Seward tidal gages it was known that NAVD88 was 0.06 meters above Mean Lower Low Water. At Seward the difference between Mean Lower Low Water and Mean High Water is 2.96 meters, so the vertical datum was adjusted from NAVD88 to Mean High Water by adding a value of -2.9 meters. The grid was then resampled from the original 0.9144 meter cellsize to 5 meter cells. This resampled grid was then converted to a GIS point feature class. The extent of the Seward LIDAR data included a portion of the ocean's surface near the shoreline. This allowed a polygon to be digitized that defined the shoreline at the time the LIDAR survey was collected. Using this polygon, data points that were returned from the ocean's surface were then eliminated. Interpolation along the eastern and western boundaries of the grid was confined to those areas where data was collected to prevent interpolation across large areas of NODATA. Source_Used_Citation_Abbreviation: Seward LIDAR Process_Date: 200702 Source_Produced_Citation_Abbreviation: ocean mask Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Keith A. Labay Contact_Address: Address_Type: mailling and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508 Contact_Voice_Telephone: 907-786-7410 Process_Step: Process_Description: The Seward harbor data was obtained from the Army Corps of Engineers as an ASCII XYZ file. Projection of the data was Alaska State Plane FIPS 5004 NAD83. Depth values were in feet. The vertical datum of the depths was Mean Lower Low Water. A GIS point feature class was created from these points and reprojected into UTM Zone 6 NAD27. Depth values were converted to meters instead of feet and values greater than or equal to zero were deleted. The vertical datum of the depths was adjusted to Mean High Water by adding a value of -2.96 meters. Using the remaining Seward harbor points, together with the Seward LIDAR data as a guide, a harbor mask was created to define the area where depth values would be determined from the Seward harbor points. Source_Used_Citation_Abbreviation: Seward harbor Process_Date: 200702 Source_Produced_Citation_Abbreviation: harbor mask Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Keith A. Labay Contact_Address: Address_Type: mailling and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508 Contact_Voice_Telephone: 907-786-7410 Process_Step: Process_Description: The multibeam bathymetry was downloaded from the internet as an ASCII YXZ file gridded to 15 meter cells. Projection of the coordinates was UTM Zone 6 NAD83 and the depths were in positive meters. The vertical datum of the depths was Mean Lower Low Water. A GIS point feature class was created from these coordinates and the depths were changed to negative values. These points were then reprojected into UTM Zone 6 NAD27. The vertical datum of the depths was adjusted to Mean High Water by adding a value of -2.96 meters. Using the ocean mask defined from the Seward LIDAR data any points that fell outside of the polygon were eliminated. Points that overlapped with areas covered by the Seward harbor mask were also eliminated. Source_Used_Citation_Abbreviation: multibeam bathymetry Source_Used_Citation_Abbreviation: ocean mask Source_Used_Citation_Abbreviation: harbor mask Process_Date: 200702 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Keith A. Labay Contact_Address: Address_Type: mailling and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508 Contact_Voice_Telephone: 907-786-7410 Process_Step: Process_Description: The three modified point datasets were merged together to create a single dataset. This point dataset was used to interpolate the final merged DEM. Gaps between the three datasets in the intertidal zone were filled during the interpolation process to create a seamless transition. Along the steep sides of Resurrection Bay the separation between the LIDAR data and multibeam bathymetry was minimal, and required little to no interpolation. A shallow intertidal area at the head of the bay represented the only large gap within the DEM filled during the interpolation process. Interpolation along the boundaries of the DEM was confined to those areas where data was collected to prevent interpolation edge effects. Grid cells outside of the area of interest appear as NODATA. Final projection of the merged DEM was UTM Zone 6 NAD27, Z-values were in meters, and the grid cell size was five meters. The grid is also provided as an ASCII comma delimited XYZ file, or a geotiff. Coordinates in the files are Geographic NAD27. Source_Used_Citation_Abbreviation: Seward LIDAR Source_Used_Citation_Abbreviation: Seward harbor Source_Used_Citation_Abbreviation: multibeam bathymetry Process_Date: 200702 Source_Produced_Citation_Abbreviation: merged DEM Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Keith A. Labay Contact_Address: Address_Type: mailling and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508 Contact_Voice_Telephone: 907-786-7410 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 2141 Column_Count: 1622 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: 6 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -147.00 Latitude_of_Projection_Origin: 0.00 False_Easting: 500000 False_Northing: 0.00 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column Coordinate_Representation: Abscissa_Resolution: 5.00 Ordinate_Resolution: 5.00 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.400000 Denominator_of_Flattening_Ratio: 294.978698 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: Mean High Water Altitude_Resolution: 1 Altitude_Distance_Units: meters Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates Depth_System_Definition: Depth_Datum_Name: Mean High Water Depth_Resolution: 1 Depth_Distance_Units: meters Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: MS 902 Box 25286 Denver Federal Center City: Lakewood State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 1-888-ASK-USGS Resource_Description: DS 374 Distribution_Liability: This world-wide web publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government of any agency thereof. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARC/INFO grid File_Decompression_Technique: zip file Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/ds/374 Fees: There is no cost for the download of these digital files Metadata_Reference_Information: Metadata_Date: 20080909 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Keith A. Labay Contact_Address: Address_Type: mailling and physical address Address: 4200 University Drive City: Anchorage State_or_Province: Alaska Postal_Code: 99508 Contact_Voice_Telephone: 907-786-7410 Contact_Electronic_Mail_Address: klabay@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998