Identification_Information: Citation: Citation_Information: Originator: Jibson, Randall W. Originator: Michael, John A. Publication_Date: 2009 Title: Maps showing seismic landslide hazards in Anchorage, Alaska Edition: Version 1.1 Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: U.S. Geological Survey Scientific Investigations Map Issue_Identification: 3077 Publication_Information: Publication_Place: Denver, Colorado Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/sim/3077/ Description: Abstract: The devastating landslides that accompanied the great 1964 Alaska earthquake showed that seismically triggered landslides are one of the greatest geologic hazards in Anchorage. Maps quantifying seismic landslide hazards are therefore important for planning, zoning, and emergency-response preparation. The accompanying maps portray seismic landslide hazards for the following conditions: (1) deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of approximately 300-900 yr; (2) shallow landslides for a peak ground acceleration (PGA) of 0.69 g, which has a return period of 475 yr, or a 10 percent probability of exceedance in 50 yr; and (3) shallow landslides for a PGA of 0.43 g, which has a return period of 2,475 yr, or a 2 percent probability of exceedance in 50 yr. Deep, translational landslide hazard zones were delineated based on previous studies of such landslides, with some modifications based on field observations of locations of deep landslides. Shallow-landslide hazards were delineated using a Newmark-type displacement analysis for the two probabilistic ground motions modeled. This data set is the vector representation of the deep, translational landslides, which occur only during great subduction-zone earthquakes that have return periods of approximately 300-900 yr. This data set is portrayed on both sheets 1 and 2 of the publication. Purpose: Portray seismic landslide hazards in Anchorage, Alaska, for planning, zoning, and emergency preparedness. The maps are not intended as a substitute for a detailed site study prior to any proposed land use. The maps neither predict nor preclude landslide occurrence in any given location; rather, they portray areas that are more or less likely to produce landslides in the shaking conditions modeled. Supplemental_Information: The methods and background used to create these data are described fully within the text accompanying the maps. It is strongly suggested that the user consult the text and be familiar with limitations in the methodology when using this data set and applying the seismic landslide hazards in Anchorage, Alaska. Raster data sets representing the shallow landslide susceptibility for steeper slopes in response to two different earthquake shaking scenarios are also available for download by the user. These data are shown independently along with the deep, translational landslides on sheets 1 and 2. Data on sheets 1 and 2 of this report are shown with base layers obtained from the GIS Section, Municipality of Anchorage, Alaska. The data are available for download: http://munimaps.muni.org/moagis/download.htm/. Available layers include roads, railroads, hydrography, and boundaries. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2009 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -150.08 East_Bounding_Coordinate: -149.68 North_Bounding_Coordinate: 61.03 South_Bounding_Coordinate: 61.26 Keywords: Theme: Theme_Keyword_Thesaurus: American Geological Institute Glossary of Geology Theme_Keyword: seismic landslide hazards Theme_Keyword: hazard mapping Place: Place_Keyword_Thesaurus: U.S. Board of Geographic Names (BGN) Geographic Names Information System (GNIS) Place_Keyword: Anchorage Place_Keyword: Alaska Access_Constraints: none Use_Constraints: None. Users of this geospatial database and geologic information derived there from should acknowledge the U.S. Geological Survey as the source of the data. Although software enables a user to display images at various scales, map data in this report should not be used at scales greater than 1:25,000. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Randall Jibson Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: Box 25046, Mail Stop 966 City: Denver State_or_Province: Colorado Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-273-8577 Contact_Facsimile_Telephone: 303-273-8600 Contact_Electronic_Mail_Address: jibson@usgs.gov Contact_Instructions: Best to contact via e-mail or telephone Browse_Graphic: Browse_Graphic_File_Name: http://pubs.usgs.gov/sim/3077/downloads/3077_sheet1_v1-1.pdf http://pubs.usgs.gov/sim/3077/downloads/3077_sheet2_v1.1.pdf Browse_Graphic_File_Description: Graphic representation of map layout. Browse_Graphic_File_Type: PDF Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500 Cross_Reference: Citation_Information: Originator: Moriwaki, Y. Originator: Idriss, I.M. Publication_Date: 1987 Title: Evaluation of ground failure susceptibility, opportunity, and potential in the urban area of Anchorage, Alaska Geospatial_Data_Presentation_Form: report and map Series_Information: Series_Name: Woodward-Clyde Consultants, Final technical report to U.S. Geological Survey, contract no. 14-08-0001-22031 Issue_Identification: none Data_Quality_Information: Logical_Consistency_Report: Polygon topology present. Completeness_Report: The data are complete for the selected zones. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The locations of features are based on observations of areas that produced deep, translational block landslides in the 1964 earthquake as well as adjacent areas that have similar geologic conditions, as identified through the analysis of Moriwaki and Idriss (1987). Lineage: Process_Step: Process_Description: The deep, translational landslide data were digitized from Moriwaki and Idriss (1987). RMS errors were noted and were always less than 6 ft. Halo zones were added to show possible zones of future extensional cracking an additional 600-1,000 ft behind these deep translational zones. The width of the halo zones are based on observations from the 1964 earthquake. A detailed discussion is found in the accompanying text. Process_Date: 2007, 2008 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: John Michael Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: Box 25046, Mail Stop 966 City: Denver State_or_Province: Colorado Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-273-8562 Contact_Facsimile_Telephone: 303-273-8600 Contact_Electronic_Mail_Address: jmichael@usgs.gov Contact_Instructions: Best to contact via e-mail or telephone Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: G-polygon Point_and_Vector_Object_Count: 6 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: State Plane Coordinate System 1983 State_Plane_Coordinate_System: SPCS_Zone_Identifier: 5004 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999900 Longitude_of_Central_Meridian: -150.000000 Latitude_of_Projection_Origin: 54.000000 False_Easting: 1640416.666667 False_Northing: 0.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.000001 Ordinate_Resolution: 0.000001 Planar_Distance_Units: survey feet Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: >"deep_transl_ls" is an ESRI vector shapefile with >attribute items in standard, shapefile feature class format. >An additional item was added to the data: > >item description >==== =========== >halo An integer value that defines whether the polygon is a > deep, translational landslide or a halo. > ‘halo’=0 represents a deep, translational landslide. > ‘halo’=1 represents a halo polygon. Entity_and_Attribute_Detail_Citation: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Information Services Contact_Address: Address_Type: mailing address Address: Box 25286, Mail Stop 306 City: Denver State_or_Province: Colorado Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 1-888-ASK-USGS Contact_Facsimile_Telephone: 303-202-4693 Resource_Description: U.S. Geological Survey Scientific Investigations Map 3077 Distribution_Liability: This database, identified as SIM 3077, has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigourous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: SHP File_Decompression_Technique: Use WinZip (http://www.winzip.com/) or other programs to decompress the file. Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/sim/3077 Fees: none Metadata_Reference_Information: Metadata_Date: 20090428 Metadata_Review_Date: 2009 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: John Michael Contact_Address: Address_Type: mailing address Address: Box 25046, Mail Stop 966 City: Denver State_or_Province: Colorado Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-273-8562 Contact_Facsimile_Telephone: 303-273-8600 Contact_Electronic_Mail_Address: jmichael@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: none Metadata_Use_Constraints: none