Seismic Hazards

Metadata also available as - [Outline]

Frequently anticipated questions:

What does this data set describe?

Title: Seismic Hazards
The King County Sensitive Areas Ordinance (SAO) defines significant seismic hazard areas as those areas of King County subject to severe risk of earthquake damage as a result of seismically induced settlement or soil liquefaction. These conditions occur in areas underlain by cohesionless soils of low density, usually in association with a shallow groundwater table.
When shaken by an earthquake, certain soils lose their ability to support a load. Some soils will actually flow like a fluid, a process called liquefaction. Loss of soil strength can also result in failure of the ground surface (e.g., surface settlement, surface cracking, landsliding) and damage to structures supported in or on the soil. Loose, water-saturated materials are the most susceptible to seismically induced ground failure. Such materials also tend to experience the most severe ground shaking during an earthquake. The geologic environment of Puget Sound commonly results in deposits of loose, lake and/or beach sedimentation proved conditions with the potential for seismically-induced liquefaction and ground failure. Likewise areas of artificial fill my also be subject to earthquake-induced settlement and loss of strength. When development is proposed on a seismic hazard area, the applicant must submit a study which demonstrates that: 1) evaluation of site-specific subsurface conditions shows that the site is not located in a seismic hazard areas; or 2) mitigation is implemented that renders the proposed development as safe as if it were not a seismic hazard area. Criteria for the design earthquake will be developed through administrative rules and will differ for critical facilities, as defined by the Uniform Building Code, and standard structures.
  1. How should this data set be cited?

    County, King, 19970101, Seismic Hazards: King County, King County, WA.

    Online Links:

    Other_Citation_Details: None

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -122.538030
    East_Bounding_Coordinate: -121.689203
    North_Bounding_Coordinate: 47.785043
    South_Bounding_Coordinate: 47.144675

  3. What does it look like?

    <> (JPG)
    JPG File of layer overlain on base of WA counties or local cities

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 01-Jan-1990
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • GT-polygon composed of chains (0)

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet.

      Projection parameters:
      Standard_Parallel: 47.5
      Standard_Parallel: 48.73333333333333
      Longitude_of_Central_Meridian: -120.8333333333333
      Latitude_of_Projection_Origin: 47.0
      False_Easting: 1640416.666666667
      False_Northing: 0.0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.00025
      Ordinates (y-coordinates) are specified to the nearest 0.00025
      Planar coordinates are specified in foot_us

      The horizontal datum used is D North American 1983 HARN.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    (Source: ESRI)

    Feature Geometry (Source: ESRI)

    Coordinates defining the features

    Hazard Type (Source: DDES)


    edit date (Source: DDES)

    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    area (Source: ESRI)

    length (Source: ESRI)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    King County GIS Center
    Attn: Paul McCombs
    Permitting GIS Program Manager
    900 Oakesdale Ave SW
    Renton, WA 98055-1219

    206-263-4867 (voice)

Why was the data set created?

This is a SAO layer. SEISM is suitable for general reference and medium to small scale map displays; and generalized analyses.

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 01-Jan-1990 (process 1 of 2)
    The layer was mapped for the 1990 Sensitive Areas Folio.

    Person who carried out this activity:

    Attn: Dennis Higgins
    Client Services Manager

    Date: 01-Jan-1993 (process 2 of 2)
    Converted to GIS by Lisa Vicknair in late 1992/ early 1993.

    Person who carried out this activity:

    Attn: Dennis Higgins
    Client Services Manager

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

  5. How consistent are the relationships among the observations, including topology?

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
King County data are made available with the understanding that they shall be used exclusively by the obtainer or his/her authorized agents. Digital products may not be reproduced or redistributed in any form or by any means without the express written authorization of King County.

  1. Who distributes the data set? (Distributor 1 of 1)

    KCGIS Center
    Attn: Cheryl Wilder
    Data Sales Coordinator
    201 S Jackson St, Suite 700
    Seattle, WA 980914

    206-296-7258 (voice)

  2. What's the catalog number I need to order this data set?


  3. What legal disclaimers am I supposed to read?

    King County disclaims any warranty of use of any digital product or data beyond that for which it was designed.

  4. How can I download or order the data?

Who wrote the metadata?

Last modified: 10-Jan-2013
Metadata author:
King County Dept. of Environmental Services
Attn: Paul McCombs
GIS Data Team Lead
900 Oakesdale Ave SW
Renton, WA 98055-1219

206-296-7258 (voice)

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.12 on Sat Apr 06 06:03:04 2019