This repository provides python scripts to calculating a variety of correlation coefficients. It includes implementations of both inter- and intra-IM non-spatial correlation models, as well as inter- and intra-IM spatial correlation models. Citations of each model are provided directly within the scripts and are also listed below.
For a more detailed review of the ground motion correlation modelling for regional seismic risk analysis please see the paper cited below:
Monteiro, V.A., O’Reilly, G.J. A review of ground motion correlation modelling for regional seismic risk analysis. Bull Earthquake Eng (2026). https://doi.org/10.1007/s10518-026-02377-0
Use "get_correlation.py" to get non-spatial correlation coefficients from several models. Inside you can find two simple example of how to use it. Use "get_spatial_correlation.py" to get inter and/or intra-IM spatial correlation coefficients from several models. Inside you can find two simple example of how to use it.
| Function | Database | Spatial Correlation (Inter-IM) | Spatial Correlation (Intra-IM ) | Non-Spatial Correlation | Intensity Measures | Reference |
|---|---|---|---|---|---|---|
| booreEtAl03.py | 1994 Northridge earthquake | - | X | - | PGA | Boore et al. 2003 |
| wangtakada05.py | Taiwan and Japanese earthquakes | - | X | - | PGV | Wang and Takada 2005 |
| bakercornell06.py | PEER Strong Motion (2000) | - | - | X | Sa(T) | Baker and Cornell 2006 |
| godahong08.py | Chi-Chi and California earthquakes | X | X | - | Sa(T), PGA | Goda and Hong 2008 |
| godaatkinson09.py | K-net and KiK-net databases | X | X | X | Sa(T), PGA | Goda and Atkinson 2009 |
| bakerjayaram08.py | NGA-W1 database | - | - | X | Sa(T) | Baker and Jayaram 2008 |
| jayarambaker09.py | NGA-W1 database | - | X | - | Sa(T) | Jayaram and Baker 2009 |
| SokolovEtAl10.py | TSMP network in Taiwan | - | X | - | PGA | Sokolov et al. 2010 |
| espositoiervolino11.py | ESM and ITACA databases | - | X | - | PGA, PGV | Esposito and Iervolino 2011 |
| espositoiervolino12.py | ESM and ITACA databases | - | X | - | Sa(T) | Esposito and Iervolino 2012 |
| bradley11.py | NGA-W1 database | - | - | X | Sa(T), PGA, PGV, Duration | Bradley 2011 |
| bradley12.py | NGA-W1 database | - | - | X | Sa(T), PGV | Bradley 2012 |
| lothbaker13.py | NGA-W1 database | X | - | - | Sa(T) | Loth and Baker 2013 |
| sokolovwenzel13.py | K-net and KiK-net databases | - | X | - | PGA, PGV | Sokolov and Wenzel 2013 |
| wangdu13.py | NGA-W1 database | X | - | - | Sa(T) | Wang and Du 2013 |
| duwang13.py | NGA-W1 database | - | X | - | Sa(T) | Du and Wang 2013 |
| cimellaro13.py | ESM database | - | - | X | Sa(T) | Cimellaro 2013 |
| akkarEtAl14.py | RESORCE database | - | - | X | Sa(T), PGA | Akkar et al. 2014 |
| bakerbradley17.py | NGA-W2 database | - | - | X | Sa(T), PGA, PGV, Duration | Baker and Bradley 2017 |
| markhvidaEtAl18.py | NGA-W2 database | X | - | - | Sa(T) | Markhvida et al. 2018 |
| heresimiranda19.py | NGA-W2 database | - | X | - | Sa(T), PGA | Heresi and Miranda 2019 |
| huanggalasso19.py | ESM and ITACA databases | - | - | X | Sa(T), PGA, PGV | Huang and Galasso 2019 |
| duning21.py | NGA-W2 | X | - | - | Sa(T), PGA, PGV, Duration | Du and Ning 2021 |
| schiappapietraEtAl22.py | ESM database | - | X | - | Sa(T) | [Schiappapietra et al 2022 |
| aldeaEtAl22 | Chilean earthquakes | - | X | - | Sa(T), PGA | [Aldea et al. 2022 |
| aristeidouEtAl24 (see https://github.com/Savvinos-Aristeidou/ANN_correlation_models.git) | NGA-W2 database | - | - | X | Sa(T), PGA, PGV, PGD, Duration, FIV3, Saavg(T) | Aristeidou et al. 2024 |
| MonteiroEtAl24 (see https://github.com/vitorazevedomonteiro/cross-spatial-correlation-model.git) | NGA-W2 and ESM database | X | - | - | Sa(T), PGA, PGV, FIV3, Saavg(T) | Monteiro V.A. et al. [2025] (under revision) |
Note that inter-IM spatial models also capture intra-IM spatial correlation by definition.