GIS Data Catalog

Seismic Hazards

Learn how to use GIS Open Data 🗺

Use this Data

Links How to use in ArcGIS Pro
Sharing Status	Public

Summary

This is a SAO layer.

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

Description

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.

Layer information

Layer Name	seism_area
Subject Category	Environment
Title	Seismic Hazards
Feature Count	68
Feature Type	Polygon
Next Update	None planned
Spatial reference	EPSG:2926
Control ID	298
Place Keywords	Washington State, King County, WA, Pacific NW
Theme Keywords	Natural Resoures, None, Enviro
Supplemental Information	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.

Table Preview

Attribute information

Shape From ESRI	Description Feature Geometry Domain Coordinates defining the features
HAZARD From DDES	Description Hazard Type Domain SEI - seismic
EDIT_DATE From DDES	Description edit date Domain Not Found
OBJECTID From ESRI	Description Internal feature number. Domain Sequential unique whole numbers that are automatically generated.
Shape.STArea() From SQL Server	Description Returns the area of a geometry instance in square units, based on the spatial reference identifier (SRID) of the geometry. Domain Double
Shape.STLength() From SQL Server	Description Returns the total length of the elements in a geometry instance. Domain Double

Contact information

Maintained by	DLS - Permitting
Primary	Paul McCombs paul.mccombs@kingcounty.gov

Terms of Use

License	Terms of use and copyright