Skip to content
Snippets Groups Projects
Model-Editions.md 7.71 KiB
Newer Older
  • Learn to ignore specific revisions
  • Powers, Peter M.'s avatar
    Powers, Peter M. committed
    # USGS Models: Editions
    
    USGS hazard models are created and updated in response to user needs. In some cases a model is
    updated in response to cyclic updates to the U.S. Building Code. In other cases, enough time has
    passed that there have been significant advancements in the science, availability of relevant
    data, or modeling procedures that warrant a model update. Every model the USGS produces is
    associated with a USGS Open-File report or refereed journal article and supporting datasets.
    However, layered on top of any given model release are bug-fixes and model improvements.
    
    
    With the update to a new codebase, [nshmp-haz](https://code.usgs.gov/ghsc/nshmp/nshmp-haz),
    
    the NSHMP has adopted [semantic versioning](http://semver.org) to keep track of different hazard
    models. For any given model region, the first number (or major version) corresponds to a particular
    release or update year. For example, we consider the initial
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    [1996 conterminous U.S. NSHM](https://earthquake.usgs.gov/hazards/hazmaps/conterminous/index.php#1996)
    to be v1.0.0. The second number (or minor version) reflects updates to a particular release that
    likely causes small changes to hazard values. The third number reflects non-hazard altering
    changes; for instance, a change to the model file format that has no consequence on computed
    hazard.
    
    The USGS NSHMP is committed to supporting current and prior model releases in any given region
    via web services. The table below provides a summary of all NSHM releases and their corresponding
    
    version numbers. Links to documentation and data for each of the models below are listed on the USGS
    [Seismic Hazard Maps and Site-Specific Data](https://www.usgs.gov/natural-hazards/earthquake-hazards/seismic-hazard-maps-and-site-specific-data)
    page.
    
    TODO: confirm model versions, tags, links (github vs gitlab...), and availability
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    
    Region | Year | Version | Static | Dynamic | Notes |
    -------|:----:|:-------:|:------:|:-------:|-------|
    
    Conterminous U.S. | 2018 | [v5.0.0](https://code.usgs.gov/ghsc/nshmp/nshm-conus-2018)<sup></sup> | |:small_blue_diamond:| |
    Conterminous U.S. | 2014 | [v4.2.0](https://github.com/usgs/nshmp-model-cous-2014/releases/tag/v4.2.0)<sup></sup> | |:small_blue_diamond:| |
    Conterminous U.S. | 2014 | [v4.1.4](https://github.com/usgs/nshmp-model-cous-2014/releases/tag/v4.1.4)<sup></sup> | |:small_blue_diamond:| |
    Conterminous U.S. | 2014 | [v4.0.0](https://github.com/usgs/nshmp-haz-fortran/releases/tag/nshm2014r1) |:small_blue_diamond:| | ASCE7-16 |
    Conterminous U.S. | 2008 | v3.3.3 | |:small_blue_diamond:| |
    Conterminous U.S. | 2008 | [v3.2.0](https://github.com/usgs/nshmp-haz-fortran/releases/tag/nshm2008r3) |:small_blue_diamond:| | |
    Conterminous U.S. | 2008 | v3.1.0 |:small_blue_diamond:| | ASCE7-10 |
    Conterminous U.S. | 2008 | v3.0.0 | | | |
    Conterminous U.S. | 2002 | v2.0.0 | | | |
    Conterminous U.S. | 1996 | v1.0.0 | | | |
    Alaska            | 2007 | v2.1.0 | |:small_blue_diamond:| |
    Alaska            | 2007 | v2.0.0 |:small_blue_diamond:| | ASCE7-10 |
    Alaska            | 1999 | v1.0.0 | | | |
    American Samoa    | 2012 | v1.0.0 | | | |
    Guam              | 2012 | v1.0.0 | | | |
    Hawaii            | 2018 | v2.0.0 | | TBD | |
    Hawaii            | 1998 | v1.1.0 | | TBD | |
    Hawaii            | 1998 | v1.0.0 |:small_blue_diamond:| | ASCE7-10 |
    Puerto Rico & <br/> U.S. Virgin Islands | 2003 | v1.0.0 | | | |
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    
    <sup></sup> __Note on the 2014 Conterminous U.S. NSHM:__ Initial publication of the
    
    [2014 model](https://www.usgs.gov/natural-hazards/earthquake-hazards/science/2014-united-states-lower-48-seismic-hazard-long-term)
    included data to support updates to the U.S. Building Code, specifically hazard curves for peak
    ground acceleration (PGA), and 0.2 and 1.0 second spectral accelerations, all at a BC boundary site
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    class with Vs30 = 760 m/s. Some time later, the model was deployed to the Unified Hazard Tool
    (UHT) and included support in the Wester U.S. for calculations at sites other than Vs30 = 760 m/s,
    consistent with dynamic calculations using the 2008 model. Subsequently, we updated the 2014
    model with [addional periods and site classes](https://pubs.er.usgs.gov/publication/ofr20181111).
    Doing so required dropping several ground motion models (GMMs) and a redistribution of logic-tree
    weights. Specifically, the Idriss (2014) model is inappropriate for use at soft soil sites and
    the Atkinson & Boore (2003) model does not support long periods (see the
    [open-file report](https://pubs.er.usgs.gov/publication/ofr20181111) for more information).
    Moving forward, we will continue to include the original dynamic version of the 2014 model
    (v4.1.4) in the UHT. However, we recommend that users consider the updated model (4.2.0).
    
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    ## Static vs. Dynamic
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    
    Historically, the USGS NSHMP has produced static datasets of hazard curves that accompany the
    'official' release or update to a model. In the context of providing interactive web services,
    such static datasets can be quickly retreived and provide most users with the data they seek.
    More complex analyses, such as deaggregations, require that a complete hazard calculation be
    performed on demand. Historically, USGS deaggregation services were provided for particular model
    years and regions, each located at a unique web address and supported by a unique codebase.
    However, it has proven too difficult to maintain numerous isolated services, and we therefore
    developed a single codebase that supports all current and prior models.
    
    Moreover, as time goes by, there may be more customization options we want to expose to users.
    However, with each additional level of customization, it quickly becomes too difficult to produce
    and version corresponding static datasets. We therefore identify model versions that support
    deaggregations and other calculations as 'dynamic'. At present, only the most current versions
    of a particular model region and year are supported via 'dynamic' calculations.
    
    In practice, this leads to results produced by 'dynamic' caluculations being somewhat different
    than those stored in static datasets of prior model minor versions, although usually not by much.
    The release notes for each model version detail the changes that give rise to changes in hazard
    between between versions. There are also differences that arise from different modeling
    assumptions between past and current codebases that are detailed below.
    
    It is important for users to know which edition they should be using. For instance if one is
    bound to use those values adopted by the U.S. building code, one of the editions marked `ASCE7-*`
    is probably most appropriate. However, if one is bound to use the most up to date source model,
    one of the dynamic editions is likely better.
    
    
    TODO: do we want to reference `nshmp-haz-ws` and is this the correct reference here?
    
    Dynamic editions are supported through web-services provided by the `nshmp-haz-ws` library.
    Static editions are supported via a separate set of services. Both are documented on the
    [web services](./NSHMP-Web-Services.md#nshmp-web-services) page.
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    ## Region specific changes
    
    Powers, Peter M.'s avatar
    Powers, Peter M. committed
    
    Changes between editions in model regions are documented in the release notes of the individual
    model repositories.
    
    
    * [Conterminous US (2014)](https://github.com/usgs/nshm-cous-2014)  
    * [Conterminous US (2008)](https://github.com/usgs/nshm-cous-2008)  
    * [Alaska (2007)](https://github.com/usgs/nshm-ak-2007)  
    
    ## Related Pages
    
    * [USGS Models](./USGS-Models.md#usgs-models)
      * [Model Editions](./Model-Editions.md#model-editions)
      * [Logic Trees & Uncertainty](./Logic-Trees-&-Uncertainty.md#logic-trees-&-uncertainty)
    * [**Documentation Index**](../README.md)
    
    ![USGS logo](./images/usgs-icon.png) &nbsp;[U.S. Geological Survey](https://www.usgs.gov)
    
    National Seismic Hazard Mapping Project ([NSHMP](https://earthquake.usgs.gov/hazards/))