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 raster representation of shallow landslides from steeper slopes, which are most predominant in shallow-crustal earthquakes. Earthquake shaking was characterized using PGA values having 2 percent probability of exceedance in 50 yr, corresponding to a return period of 2,475 yr. This data set is portrayed on sheet 1 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. A raster data set representing the shallow landslide susceptibility for steeper slopes with earthquake shaking characterized using PGA values having 10 percent probability of exceedance in 50 yr are also available for download by the user. These data are shown on sheet 2 of this report. A vector representation of the deep, translational landslides that occur only during great subduction-zone earthquakes that have return periods of approximately 300-900 yr is also available for download by the user. These data are shown on both sheets 1 and 2 of this report. 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 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: Jibson, R.W. Originator: Harp, E.L. Originator: Michael, J.A. Publication_Date: 1998 Title: A method for producing digital probabilistic seismic landslide hazard maps: An example from southern California Geospatial_Data_Presentation_Form: document Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: 98-113 Cross_Reference: Citation_Information: Originator: Jibson, R.W. Originator: Harp, E.L. Originator: Michael, J.A. Publication_Date: 2000 Title: A method for producing digital probabilistic seismic landslide hazard maps Geospatial_Data_Presentation_Form: document Series_Information: Series_Name: Engineering Geology Issue_Identification: v. 58, p. 271-289 Data_Quality_Information: Logical_Consistency_Report: This raster dataset is consistent in both the area and cell size of all input parameter rasters used in the analysis. Completeness_Report: The data are complete for the Anchorage bowl within the Municipality of Anchorage. Lineage: Process_Step: Process_Description: Methods used in Jibson and others (1998, 2000) were applied in Anchorage, Alaska, to identify and quantify shallow-landslide hazards during earthquakes. Disparate data sets were accumulated that represented input parameters in the regression model referenced above. Specific data included slope, shear strength, and earthquake shaking. Data were projected into a common window and cell size to facilitate the overlay analysis. A detailed discussion of this process is detailed in the accompanying text. Process_Date: 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: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 4107 Column_Count: 3965 Vertical_Count: 1 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: row and column Coordinate_Representation: Abscissa_Resolution: 20.000000 Ordinate_Resolution: 20.000000 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: >"sheet1_dn2p50yr" is a floating point ESRI grid. The raster dataset >contains the usual grid attribute, "VALUE," which represents Newmark >displacement (dn) computed for each grid cell using methods and >parameters described in the accompanying text. Units for the computed >cell values are centimeters. The values of dn are depicted on sheets 1 >and 2 as a "stoplight" range of colors to show estimated failure >probabilites. The ranges of dn and their representative color and >estimated failure probability for the ground-shaking levels modeled are: > >range of VALUE color and estimate of landslide occurrence >============== ========================================== > 0 1 5 VALUE>15 red; Very high likelihood 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: ARCE File_Decompression_Technique: Use WinZip (http://www.winzip.com/) or other programs to decompress the file. Use ESRI ArcInfo "Import" command or Coverage tools within ArcGIS. 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