Uniform Hazard Endpoint Documentation

This endpoint returns NSHM uniform hazard ground motion values for PGA and select SA periods. The data are typically computed for NEHRP site class BC but some data may be available at other site classes. The data have not been adjusted for maximum direction or other design-specific factors. The data may be used as inputs for computing ground motion data suitable for use with the specified reference document.

This software is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The software has not received final approval by the U.S. Geological Survey (USGS). No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. The software is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the software.

Request Parameters

Required parameters

latitude
Latitude for location at which to fetch results
Example: 34
longitude
Longitude for location at which to fetch results
Example: -118
referenceDocument
Design code reference document corresponding to hazard dataset for which to fetch results
Example: ASCE41-13
siteClass
[Optional] NEHRP site class identifying the site class of the uniform hazard data to retrieve
Example: BC

Output

Web service response

request
date
Timestamp
Example: “YYYY-MM-DDThh:mm:ssZ”
referenceDocument
Design code reference document corresponding to hazard dataset for returned results
Example: “ASCE41-13”
status
String (“success” or “error”)
Example: “success”
url
URL to reproduce this result
Example: “ … /uniform-hazard.json?latitude=34&longitude=-118&referenceDocument=ASCE41-13&siteClass=BC”
parameters
latitude
Latitude for location at which to fetch results
Example: 34
longitude
Longitude for location at which to fetch results
Example: -118
siteClass
NEHRP site class for which to fetch results.
Example: “BC”
response
data
pgauh
Mapped uniform hazard ground motion value (Peak Ground Acceleration)
sauh
periods
Array of spectral periods corresponding to the uniform hazard ground motion ordinates
ordinates
Array of uniform hazard ground motion values corresponding to the spectral periods
metadata
gridSpacing
The grid spacing (decimal degrees) for the underlying dataset
modelVersion
Identifier for the underlying model version in the database
regionName
Identifier for the underlying region name in the database
spatialInterpolationMethod
Identifier for the interpolation method used to obtain data for location of interest from underlying gridded datasets
vs30
The time-averaged shear-wave velocity to 30 m depth for which the returned uniform hazard ground motion values apply

Example

Request

… /uniform-hazard.json?latitude=34&longitude=-118&referenceDocument=ASCE41-13&siteClass=BC

Response

          {
            request:{
               date:"2019-06-13T16:03:11.460Z",
               referenceDocument:"ASCE41-13",
               status:"success",
               url:"http://localhost:8000/ws/designmaps/uniform-hazard.json?referenceDocument=ASCE41-13&latitude=34&longitude=-118&siteClass=BC",
               parameters:{
                  latitude:34,
                  longitude:-118,
                  siteClass:"BC"
               }
            },
            response:{
               data:{
                  pgauh:0.89359,
                  sauh:{
                     periods:[
                        0.2,
                        1
                     ],
                     ordinates:[
                        2.2676,
                        0.67503
                     ]
                  }
               },
               metadata:{
                  gridSpacing:0.01,
                  modelVersion:"v3.1.x",
                  regionName:"E2008R2_COUS0P01_UniformHazard",
                  spatialInterpolationMethod:"linearlinearlinear",
                  vs30:760
               }
            }
         }