Ground-Motion-Models.md

# Ground Motion Models (GMMs)

Ground motion models (GMMs) forecast the range of ground motions that may occur conditioned on
the occurrence of various earthquakes. The following tables list the GMMs supported in NSHMs. It
is not uncommon for a GMM to have multiple concrete implementations. For instance, most subduction
GMMs, as published, support both interface and intraslab events.

[TOC]

## GMM Configuration

A **gmm-config.json** file governs how GMMs are applied in a NSHM and is required adjacent to any
`gmm-tree.json` file. It specifies a maximum distance at which associated GMMs are applicable. It
may also specify a model of additional epistemic uncertainty and the logic tree used to apply it to
median ground motions derived from the GMMs. If no such model is required, the `epistemic-model`
and `epistemic-tree` members must be `null`. This uncertainty is disctinct from the built-in
aleatory variability (standard deviation or sigma) of the GMMs themselves. See
[GMM Uncertainty Models](#gmm-uncertainty-models) for details on additional epistemic uncertainty
in GMMs.

A sample `gmm-config.json` file that specifies no additional epistemic uncertainty model:

```json
{
  "max-distance": 300.0,
  "epistemic-model": null,
  "epistemic-tree": null
}
```

The following sample `gmm-config.json` file applies the NGA-West 2 epistemic uncertainty model:

```json
{
  "max-distance": 300.0,
  "epistemic-model": "NGA_WEST2",
  "epistemic-tree": [
    { "id": "epi+", "weight": 0.185, "value": 1.0 },
    { "id": "none", "weight": 0.63, "value": 0.0 },
    { "id": "epi-", "weight": 0.185, "value": -1.0 }
  ]
}
```

## GMM Uncertainty Models

*nshmp-haz* supports additional epistemic uncertainty models derived from the PEER NGA-West 1
and PEER NGA-West 2 projects. These models both have factors for distance (`Rrup`) bins
Rrup < 10 km, 10 km <= Rrup, < 30 km, and 30 km <= Rrup, and for magnitude bins M < 6.0, 6.0 <=
M < 7.0, and 7.0 <= M. These models can be applied within the `gmm-config.json` file as shown in
the [GMM Uncertainty](#gmm-uncertainty) section above.

## GMMs By Tectonic Setting

GMMs available in *nshmp-haz* are tabulated by tectonic setting below. See the javadocs for the
[GMM Package](https://earthquake.usgs.gov/nshmp/docs/nshmp-lib/gov/usgs/earthquake/nshmp/gmm/package-summary.html)
for implementation details of each GMM and comprehensive lists of GMM IDs.

### Active Crust GMMs

Reference | ID | Component | Notes
:---------|:---|:----------|:------:
**NGA-West 2**
[Abrahamson et al., 2014](http://dx.doi.org/10.1193/070913EQS198M) | ASK_14<br>ASK_14_BASIN | RotD50 |
[Boore et al., 2014](http://dx.doi.org/10.1193/070113EQS184M) | BSSA_14<br>BSSA_14_BASIN | RotD50 |
[Campbell & Bozorgnia, 2014](http://dx.doi.org/10.1193/062913EQS175M)| CB_14<br>CB_14_BASIN | RotD50 |
[Chiou & Youngs, 2014](http://dx.doi.org/10.1193/072813EQS219M) | CY_14<br>CY_14_BASIN | RotD50 |
[Idriss, 2014](http://dx.doi.org/10.1193/070613EQS195M) | IDRISS_14 | RotD50 |
**NGA-West 1**
[Boore & Anderson, 2008](http://dx.doi.org/10.1193/1.2830434) | BA_08 | GMRotI50 |
[Campbell & Bozorgnia, 2008](http://dx.doi.org/10.1193/1.2857546) | CB_08 | GMRotI50 |
[Chiou & Youngs, 2008](http://dx.doi.org/10.1193/1.2894832) | CY_08 | GMRotI50 |
[Gulerce & Abrahamson, 2011](http://dx.doi.org/10.1193/1.3651317) | GA_11 | V/H |
**Other**
[Abrahamson & Silva, 1997](http://dx.doi.org/10.1785/gssrl.68.1.94) | AS_97 | Average horizontal |
[Boore et al., 1997](http://dx.doi.org/10.1785/gssrl.68.1.128)<br>[Boore, 2005](http://dx.doi.org/10.1785/gssrl.76.3.368) | BJF_97 | Random horizontal | 1
[Campbell, 1997](http://dx.doi.org/10.1785/gssrl.68.1.154)<br>[errata, 2000](http://dx.doi.org/10.1785/gssrl.71.3.352)<br>[errata, 2001](http://dx.doi.org/10.1785/gssrl.72.4.474) | CAMPBELL_97 | Geometric mean | 1
[Campbell & Bozorgnia, 2003](http://dx.doi.org/10.1785/0120020029)<br>[errata, 2003a](http://dx.doi.org/10.1785/0120030099)<br>[errata, 2003b](http://dx.doi.org/10.1785/0120030143) | CB_03 | Average horizontal | 1
[McVerry et al., 2000](http://doi.org/10.5459/BNZSEE.39.1.1-58) | MCVERRY_00_CRUSTAL<br>MCVERRY_00_VOLCANIC | Max-horizontal implemented,<br>model supports geometric mean | 2
[Sadigh et al., 1997](http://dx.doi.org/10.1785/gssrl.68.1.180) | SADIGH_97 | Geometric mean | 3
[Zhao et al., 2016](http://dx.doi.org/10.1785/0120150063) | ZHAO_16_SHALLOW_CRUST<br>ZHAO_16_UPPER_MANTLE | Geometric mean<br>(random orientation) |

¹ Soft rock sites only (Vs30 760 m/s)  
² New Zealand model, does not correspond directly with US site class model  
³ Also used for interface sources in 2007 Alaska NSHM  

### Stable Crust GMMs

Reference | ID | Component | Notes
:---------|:---|:----------|:------:
**NGA-East**
NGA-East<br>[Goulet et al., 2017](https://peer.berkeley.edu/sites/default/files/christine-a-goulet-yousef-bozorgnia-2017_03_0.pdf) | NGA_EAST_USGS¹<br>NGA_EAST_USGS_SEEDS¹ | RotD50 | 2
[Shahjouei and Pezeshk, 2016](http://dx.doi.org/10.1785/0120140367) | NGA_EAST_SEED_SP16 | RotD50 | 3
**Other**
[Atkinson, 2008](http://dx.doi.org/10.1785/0120070199)<br>[Atkinson & Boore, 2011](http://dx.doi.org/10.1785/0120100270) | ATKINSON_08_PRIME | horizontal | 4
[Atkinson & Boore, 2006](http://dx.doi.org/10.1785/0120050245) | AB_06_*<br>140BAR \| 200BAR<br>none \| \_AB \| \_J | horizontal | 4
[Atkinson & Boore, 2006](http://dx.doi.org/10.1785/0120050245)<br>[Atkinson & Boore, 2011](http://dx.doi.org/10.1785/0120100270) | AB_06_PRIME | horizontal | 4
[Campbell, 2003](http://dx.doi.org/10.1785/0120020002) | CAMPBELL_03<br>CAMPBELL_03_AB<br>CAMPBELL_03_J | Geometric mean | 4
[Frankel et al., 1996](https://pubs.usgs.gov/of/1996/532/) | FRANKEL_96<br>FRANKEL_96_AB<br>FRANKEL_96_J | not specified | 4
[Graizer & Kalkan, 2015](http://dx.doi.org/10.3133/ofr20151009)<br>[Graizer & Kalkan, 2016](http://dx.doi.org/10.1785/0120150194) | GK_15 | Geometric mean<br>(random orientation) |
[Pezeshk et al., 2011](http://dx.doi.org/10.1785/0120100144) | PEZESHK_11 | GMRotI50 | 4
[Silva et al., 2002](http://www.pacificengineering.org/CEUS/Development%20of%20Regional%20Hard_ABC.pdf) | SILVA_02<br>SILVA_02_AB<br>SILVA_02_J | Average horizontal | 4
[Somerville et al., 2001](https://earthquake.usgs.gov/static/lfs/nshm/conterminous/2008/99HQGR0098.pdf) | SOMERVILLE_01 | not specified | 4
[Tavakoli & Pezeshk, 2005](http://dx.doi.org/10.1785/0120050030) | TP_05<br>TP_05_AB<br>TP_05_J | not specified | 4
[Toro et al., 1997](http://dx.doi.org/10.1785/gssrl.68.1.41)<br>[Toro, 2002](http://www.ce.memphis.edu/7137/PDFs/attenuations/Toro_2001_(modification_1997).pdf) | TORO_97_MB<br>TORO_97_MW | not specified | 4

¹ See [Gmm javadocs](https://earthquake.usgs.gov/nshmp/docs/nshmp-lib/gov/usgs/earthquake/nshmp/gmm/Gmm.html)
for individual NGA-East component model IDs  
² Mean values are not clamped  
³ Shahjouei and Pezeshk (2016) is a NGA-East seed model  
⁴ Mean values clamped  

### Subduction GMMs

*Note: See the [GMM javadocs](https://earthquake.usgs.gov/nshmp/docs/nshmp-lib/gov/usgs/earthquake/nshmp/gmm/Gmm.html)
for a comprehensive list of GMM IDs.*

Reference | ID | Component | Notes
:---------|:---|:----------|:------:
**NGA-Subduction**
[Abrahamson & Gülerce, 2020](https://peer.berkeley.edu/sites/default/files/2020_25.pdf) | AG_20_*<br>GLOBAL \| CASCADIA \| ALASKA<br>INTERFACE \| SLAB<br> (none) \| \_BASIN | RotD50
[Kuehn et al., 2020](https://peer.berkeley.edu/sites/default/files/2020_04_kuehn_final.pdf) | KBCG_20_*<br>GLOBAL \| CASCADIA \| ALASKA<br>INTERFACE \| SLAB<br>(none) \| \_BASIN | RotD50
[Parker et al., 2020](https://peer.berkeley.edu/sites/default/files/2020_03_parker_final.pdf) | PSHAB_20_*<br>GLOBAL \| CASCADIA \| ALASKA<br>INTERFACE \| SLAB<br>(none) \|\_BASIN | RotD50
**Other**
[Atkinson & Boore, 2003](http://dx.doi.org/10.1785/0120020156) | AB_03_*<br>GLOBAL \| CASCADIA<br>INTERFACE \| SLAB<br> (none) \| \_LOW_SAT| horizontal |
[Atkinson & Macias, 2009](http://dx.doi.org/10.1785/0120080147) | AM_09_INTERFACE<br>AM_09_INTERFACE_BASIN | Geometric mean | 1
BC Hydro<br>[Abrahamson et al., 2016](http://dx.doi.org/10.1193/051712EQS188MR) | BCHYDRO_12_*<br>INTERFACE \| SLAB<br> (none) \| \_BASIN<br>(none) \| \_BACKARC | Geometric mean |
BC Hydro NGA<br>[Abrahamson et al., 2018](https://peer.berkeley.edu/sites/default/files/2018_02_abrahamson_9.10.18.pdf)² | BCHYDRO_18_NGA_*<br>INTERFACE \| SLAB<br> (none) \| \_NO_EPI | Geometric mean | 3
[McVerry et al., 2000](http://doi.org/10.5459/BNZSEE.39.1.1-58) | MCVERRY_00_INTERFACE<br>MCVERRY_00_SLAB<br>MCVERRY_00_VOLCANIC | Max-horizontal,<br>also supports geometric mean | 4
[Youngs et al., 1997](http://dx.doi.org/10.1785/gssrl.68.1.58) | YOUNGS_97_INTERFACE<br>YOUNGS_97_SLAB | Geometric mean |
[Zhao et al., 2006](http://dx.doi.org/10.1785/0120050122) | ZHAO_06_*<br>INTERFACE \| SLAB<br> (none) \| \_BASIN | Geometric mean |

¹ Interface only  
² Likely to be superseded by the final EQ Spectra paper  
³ Calibrated for Cascadia use only  
⁴ New Zealand model, does not correspond directly with US site class model  

### Regional and Specialized GMMs

| Reference | ID | Component | Notes |
|:----------|:---|:----------|:-----:|
| **Hawaii**
| [Atkinson, 2010](http://dx.doi.org/10.1785/0120090098) | ATKINSON_10 | geometric mean |
| [Munson & Thurber, 1997](https://pubs.geoscienceworld.org/ssa/srl/article-abstract/68/1/41/142160/Model-of-Strong-Ground-Motions-from-Earthquakes-in) | MT_97 | Max-horizontal | 1
| [Wong et al., 2015](http://doi.org/10.1193/012012EQS015M) | WONG_15 | Average horizontal |
| **New Zealand**
| [McVerry et al., 2000](http://doi.org/10.5459/BNZSEE.39.1.1-58) | MCVERRY_00_CRUSTAL<br>MCVERRY_00_VOLCANIC<br>MCVERRY_00_INTERFACE<br>MCVERRY_00_SLAB | Max-horizontal <br>(also geometric mean) | 2
| **Induced Seismicity**
| [Atkinson, 2015](http://dx.doi.org/10.1785/0120140142) | ATKINSON_15 | orientation-independent<br>horizontal |

¹ Munson & Thurber (1997) supports PGA and 0.2 seconds, with an additional term applied for M > 7.  
² McVerry et al. (2000) is a New Zealand model and does not correspond directly with the U.S. site
   class model.  

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## Related Pages

* [Hazard Model](./Hazard-Model.md#hazard-model)
  * [Model Structure](./Model-Structure.md#model-structure)
  * [Model Files](./Model-Files.md#model-files)
  * [Source Types](./Source-Types.md#source-types)
  * [Magnitude Frequency Distributions (MFDs)](./Magnitude-Frequency-Distributions.md#magnitude-frequency-distributions)
  * [Rupture Scaling Relations](./Rupture-Scaling-Relations.md#rupture-scaling-relations)
  * [Ground Motion Models (GMMs)](./Ground-Motion-Models.md#ground-motion-models)
* [**Documentation Index**](../README.md)

---
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National Seismic Hazard Mapping Project ([NSHMP](https://earthquake.usgs.gov/hazards/))