NEHRP-2020 Web Service Documentation

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.
This reference document is still under development and is very early in nature. The following points should be noted:

Request Parameters

Required parameters

latitude
Latitude of site of interest, in decimal degrees
Example: 34.05
longitude
Longitude of site of interest, in decimal degrees
Example: -118.25
riskCategory
Risk Category, as defined in Chapter 1
Options: I, II, III, or IV
siteClass
Site Class, as defined in Chapter 20
Options: Default, A, B, BC, C, CD, D, DE, E
title
Title for this request (can be blank)
Example: Los Angeles site

Output

Web service response

request
date
Timestamp, in format YYYY-MM-DDThh:mm:ssZ
Example: “YYYY-MM-DDThh:mm:ssZ”
referenceDocument
Seismic design reference document
Example: “NEHRP-2020”
status
Status of response to request, either “success” or “error”
Example: “success”
url
URL of request that returns this response
Example: /nehrp-2020.json?latitude=34&longitude=-118&riskCategory=III&siteClass=C&title=Example”
parameters
latitude
Latitude of site of interest, in decimal degrees
Example: 34.05
longitude
Longitude of site of interest, in decimal degrees
Example: -118.25
riskCategory
Risk Category, as defined in Chapter 1
Options: I, II, III, or IV
siteClass
Site Class, as defined in Chapter 20
Options: Default, A, B, BC, C, CD, D, DE, E
title
Title for this request (can be blank)
Example: Los Angeles site
response
data
pgam
PGAM, the mapped Geometric-Mean Maximum Considered Earthquake (MCEG) peak ground acceleration for the user-specified Site Class, in units of g
sms
SMS, the MCER spectral response acceleration for short periods (of the two-period spectrum) and the user-specified Site Class
sm1
SM1, the MCER spectral response acceleration for 1 second (of the two-period spectrum) and the user-specified Site Class
sds
SDS, the design spectral response acceleration for short periods (of the two-period spectrum) and the user-specified Site Class
sd1
SD1, the design spectral response acceleration for 1 second (of the two-period spectrum) and the user-specified Site Class
sdc
Seismic design category
ss
SS, the MCER spectral response acceleration at 0.2 seconds for Site Class BC
s1
S1, the MCER spectral response acceleration at 1 second for Site Class BC
ts
T s = S D1 / S Ds , in Seconds
t0
T 0 = 0.2 * T s , in Seconds
tl
TL, the mapped long-period transition period, in seconds
cv
Cv, the vertical coefficient
multiPeriodDesignSpectrum
Multi-period design response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
multiPeriodMCErSpectrum
Multi-period design response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
twoPeriodDesignSpectrum
Two-period design response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
twoPeriodMCErSpectrum
Two-period Risk-targeted Maximum Considered Earthquake (MCER) response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
verticalDesignSpectrum
Vertical design response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
verticalMCErSpectrum
Vertical Risk-targeted Maximum Considered Earthquake (MCER) response spectrum
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
underlyingData
pgauh
Probabilistic uniform-hazard, geometric mean peak ground acceleration, in units of g
pga84th
Deterministic 84th-percentile, geometric mean peak ground acceleration, in units of g
riskTargetedSpectrum
Probabilistic risk-targeted, maximum-direction response spectrum (for 1%-in-50-years collapse probability)
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
eightyFourthSpectrum
Deterministic 84th-percentile, maximum-direction response spectrum (without deterministic lower limit)
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
metadata
modelVersion
Version of the underlying USGS National Seismic Hazard Model
vs30
vs30, the average shear wave velocity used for the user-specified Site Class, in units of m/s
scienceBaseURL
URL of ScienceBase webpage where files of underlying gridded values are posted
spatialInterpolationMethod
Identifier for the interpolation method used to obtain data for location of interest from underlying gridded datasets
maxDirFactors
Maximum-direction response scale factors
periods
Array of spectral periods, in seconds
ordinates
Array of scale factors
dllSpectrum
Deterministic lower limit response spectrum for the user-specified Site Class
periods
Array of spectral periods, in seconds
ordinates
Array of spectral response accelerations, in units of g
pgadFloor
Deterministic lower limit peak ground acceleration (PGAG) for the user-specified Site Class, in units of g

Example

Request

/nehrp-2020.json?latitude=34&longitude=-118&riskCategory=III&siteClass=C&title=Example

Response

          {
            request:{
               date:"2019-06-13T15:49:32.786Z",
               referenceDocument:"NEHRP-2020",
               status:"success",
               url:"http://localhost:8000/ws/designmaps/nehrp-2020.json?latitude=34&longitude=-118&riskCategory=III&siteClass=C&title=Example",
               parameters:{
                  latitude:34,
                  longitude:-118,
                  riskCategory:"III",
                  siteClass:"C",
                  title:"Example"
               }
            },
               data:{
                  pgam:0.55,
                  sms:1.86,
                  sm1:1.07,
                  sds:1.24,
                  sd1:0.71,
                  sdc:"E",
                  ss:1.8,
                  s1:0.75,
                  ts:0.576,
                  t0:0.115,
                  tl:8,
                  cv:null,
                  multiPeriodDesignSpectrum:{
                     periods:[
                        0,
                        0.01,
                        0.02,
                        0.03,
                        0.05,
                        0.075,
                        0.1,
                        0.15,
                        0.2,
                        0.25,
                        0.3,
                        0.4,
                        0.5,
                        0.75,
                        1,
                        1.5,
                        2,
                        3,
                        4,
                        5,
                        7.5,
                        10
                     ],
                     ordinates:[
                        0.58,
                        0.58,
                        0.59,
                        0.63,
                        0.77,
                        0.95,
                        1.09,
                        1.28,
                        1.37,
                        1.37,
                        1.34,
                        1.23,
                        1.12,
                        0.87,
                        0.71,
                        0.45,
                        0.32,
                        0.2,
                        0.14,
                        0.11,
                        0.068,
                        0.045
                     ]
                  },
                  multiPeriodMCErSpectrum:{
                     periods:[
                        0,
                        0.01,
                        0.02,
                        0.03,
                        0.05,
                        0.075,
                        0.1,
                        0.15,
                        0.2,
                        0.25,
                        0.3,
                        0.4,
                        0.5,
                        0.75,
                        1,
                        1.5,
                        2,
                        3,
                        4,
                        5,
                        7.5,
                        10
                     ],
                     ordinates:[
                        0.87,
                        0.88,
                        0.89,
                        0.95,
                        1.15,
                        1.43,
                        1.64,
                        1.93,
                        2.05,
                        2.06,
                        2.01,
                        1.85,
                        1.68,
                        1.31,
                        1.07,
                        0.68,
                        0.48,
                        0.3,
                        0.21,
                        0.16,
                        0.1,
                        0.068
                     ]
                  },
                  twoPeriodDesignSpectrum:{
                     periods:[
                        0,
                        0.025,
                        0.05,
                        0.1,
                        0.12,
                        0.15,
                        0.2,
                        0.25,
                        0.3,
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                        0.9,
                        0.95,
                        1,
                        1.05,
                        1.1,
                        1.15,
                        1.2,
                        1.25,
                        1.3,
                        1.35,
                        1.4,
                        1.45,
                        1.5,
                        1.55,
                        1.6,
                        1.65,
                        1.7,
                        1.75,
                        1.8,
                        1.85,
                        1.9,
                        1.95,
                        2,
                        2.05,
                        2.1,
                        2.15,
                        2.2,
                        2.25,
                        2.3,
                        2.35,
                        2.4,
                        2.45,
                        2.5,
                        2.55,
                        2.6,
                        2.65,
                        2.7,
                        2.75,
                        2.8,
                        2.85,
                        2.9,
                        2.95,
                        3,
                        3.05,
                        3.1,
                        3.15,
                        3.2,
                        3.25,
                        3.3,
                        3.35,
                        3.4,
                        3.45,
                        3.5,
                        3.55,
                        3.6,
                        3.65,
                        3.7,
                        3.75,
                        3.8,
                        3.85,
                        3.9,
                        3.95,
                        4,
                        4.05,
                        4.1,
                        4.15,
                        4.2,
                        4.25,
                        4.3,
                        4.35,
                        4.4,
                        4.45,
                        4.5,
                        4.55,
                        4.6,
                        4.65,
                        4.7,
                        4.75,
                        4.8,
                        4.85,
                        4.9,
                        4.95,
                        5,
                        5.05,
                        5.1,
                        5.15,
                        5.2,
                        5.25,
                        5.3,
                        5.35,
                        5.4,
                        5.45,
                        5.5,
                        5.55,
                        5.6,
                        5.65,
                        5.7,
                        5.75,
                        5.8,
                        5.85,
                        5.9,
                        5.95,
                        6,
                        6.05,
                        6.1,
                        6.15,
                        6.2,
                        6.25,
                        6.3,
                        6.35,
                        6.4,
                        6.45,
                        6.5,
                        6.55,
                        6.6,
                        6.65,
                        6.7,
                        6.75,
                        6.8,
                        6.85,
                        6.9,
                        6.95,
                        7,
                        7.05,
                        7.1,
                        7.15,
                        7.2,
                        7.25,
                        7.3,
                        7.35,
                        7.4,
                        7.45,
                        7.5,
                        7.55,
                        7.6,
                        7.65,
                        7.7,
                        7.75,
                        7.8,
                        7.85,
                        7.9,
                        7.95,
                        8,
                        8.05,
                        8.1,
                        8.15,
                        8.2,
                        8.25,
                        8.3,
                        8.35,
                        8.4,
                        8.45,
                        8.5,
                        8.55,
                        8.6,
                        8.65,
                        8.7,
                        8.75,
                        8.8,
                        8.85,
                        8.9,
                        8.95,
                        9
                     ],
                     ordinates:[
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                        0.66,
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                        1.19,
                        1.1,
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                        0.15,
                        0.15,
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                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
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                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.1,
                        0.1,
                        0.1,
                        0.1,
                        0.1,
                        0.1,
                        0.1,
                        0.1,
                        0.099,
                        0.098,
                        0.098,
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                        0.096,
                        0.096,
                        0.095,
                        0.094,
                        0.094,
                        0.093,
                        0.093,
                        0.092,
                        0.091,
                        0.091,
                        0.09,
                        0.09,
                        0.089,
                        0.088,
                        0.087,
                        0.086,
                        0.085,
                        0.084,
                        0.083,
                        0.082,
                        0.081,
                        0.08,
                        0.079,
                        0.078,
                        0.077,
                        0.076,
                        0.075,
                        0.074,
                        0.074,
                        0.073,
                        0.072,
                        0.071,
                        0.07
                     ]
                  },
                  twoPeriodMCErSpectrum:{
                     periods:[
                        0,
                        0.025,
                        0.05,
                        0.1,
                        0.12,
                        0.15,
                        0.2,
                        0.25,
                        0.3,
                        0.35,
                        0.4,
                        0.45,
                        0.5,
                        0.55,
                        0.58,
                        0.6,
                        0.65,
                        0.7,
                        0.75,
                        0.8,
                        0.85,
                        0.9,
                        0.95,
                        1,
                        1.05,
                        1.1,
                        1.15,
                        1.2,
                        1.25,
                        1.3,
                        1.35,
                        1.4,
                        1.45,
                        1.5,
                        1.55,
                        1.6,
                        1.65,
                        1.7,
                        1.75,
                        1.8,
                        1.85,
                        1.9,
                        1.95,
                        2,
                        2.05,
                        2.1,
                        2.15,
                        2.2,
                        2.25,
                        2.3,
                        2.35,
                        2.4,
                        2.45,
                        2.5,
                        2.55,
                        2.6,
                        2.65,
                        2.7,
                        2.75,
                        2.8,
                        2.85,
                        2.9,
                        2.95,
                        3,
                        3.05,
                        3.1,
                        3.15,
                        3.2,
                        3.25,
                        3.3,
                        3.35,
                        3.4,
                        3.45,
                        3.5,
                        3.55,
                        3.6,
                        3.65,
                        3.7,
                        3.75,
                        3.8,
                        3.85,
                        3.9,
                        3.95,
                        4,
                        4.05,
                        4.1,
                        4.15,
                        4.2,
                        4.25,
                        4.3,
                        4.35,
                        4.4,
                        4.45,
                        4.5,
                        4.55,
                        4.6,
                        4.65,
                        4.7,
                        4.75,
                        4.8,
                        4.85,
                        4.9,
                        4.95,
                        5,
                        5.05,
                        5.1,
                        5.15,
                        5.2,
                        5.25,
                        5.3,
                        5.35,
                        5.4,
                        5.45,
                        5.5,
                        5.55,
                        5.6,
                        5.65,
                        5.7,
                        5.75,
                        5.8,
                        5.85,
                        5.9,
                        5.95,
                        6,
                        6.05,
                        6.1,
                        6.15,
                        6.2,
                        6.25,
                        6.3,
                        6.35,
                        6.4,
                        6.45,
                        6.5,
                        6.55,
                        6.6,
                        6.65,
                        6.7,
                        6.75,
                        6.8,
                        6.85,
                        6.9,
                        6.95,
                        7,
                        7.05,
                        7.1,
                        7.15,
                        7.2,
                        7.25,
                        7.3,
                        7.35,
                        7.4,
                        7.45,
                        7.5,
                        7.55,
                        7.6,
                        7.65,
                        7.7,
                        7.75,
                        7.8,
                        7.85,
                        7.9,
                        7.95,
                        8,
                        8.05,
                        8.1,
                        8.15,
                        8.2,
                        8.25,
                        8.3,
                        8.35,
                        8.4,
                        8.45,
                        8.5,
                        8.55,
                        8.6,
                        8.65,
                        8.7,
                        8.75,
                        8.8,
                        8.85,
                        8.9,
                        8.95,
                        9
                     ],
                     ordinates:[
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                        0.15,
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                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.14,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.13,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.12,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11,
                        0.11
                     ]
                  },
                  verticalDesignSpectrum:{
                     periods:[

                     ],
                     ordinates:[

                     ]
                  },
                  verticalMCErSpectrum:{
                     periods:[

                     ],
                     ordinates:[

                     ]
                  },
                  underlyingData:null
               },
               metadata:{
                  vs30:530,
                  modelVersion:"v5.0.x",
                  pgadFloor:0.55,
                  pgadPercentileFactor:1,
                  sadFloor:{
                     periods:[
                        0,
                        0.01,
                        0.02,
                        0.03,
                        0.05,
                        0.075,
                        0.1,
                        0.15,
                        0.2,
                        0.25,
                        0.3,
                        0.4,
                        0.5,
                        0.75,
                        1,
                        1.5,
                        2,
                        3,
                        4,
                        5,
                        7.5,
                        10
                     ],
                     ordinates:[
                        0.73,
                        0.73,
                        0.74,
                        0.79,
                        0.96,
                        1.19,
                        1.37,
                        1.61,
                        1.71,
                        1.71,
                        1.66,
                        1.53,
                        1.38,
                        1.07,
                        0.86,
                        0.6,
                        0.45,
                        0.31,
                        0.24,
                        0.19,
                        0.11,
                        0.07
                     ]
                  },
                  sadPercentileFactor:{
                     periods:[
                        0,
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