gmKriger 1.1.1

Kriging-based ground motion intensity measure calculator.

gmKriger

gmKriger: A Kriging-based ground motion intensity measure (GMIM) calculator. gmKriger computes GMIMs for past earthquake events given a site's location (latitude and longitude) and the site's Vs30. gmKriger uses Ordinary Kriging interpolation and spatial correlation model developed using a Bayesian approach, ground motion data, and the functional forms proposed by Bodenmann et al. (2023).

Ground motion intensity measures (GMIMs) and units

GMIM	Key	Unit
Peak ground acceleration	PGA	g
Peak ground velocity	PGV	cm/s
Arias intensity	Ia	m/s
Cumulative absolute velocity	CAV	m/s

Models available

Get them using this code.

The spatial correlation models for the events and ground motion intensity measures below are accessible via DesignSafe (Pretell et al. 2023).

Earthquake	PGA	PGV	Ia	CAV
1968 M8.2 Tokachi-Oki	No	No	Yes	Yes
1971 M6.6 San Fernando	Yes	Yes	Yes	Yes
1978 M7.7 Miyagiken-Oki	No	No	Yes	Yes
1979 M6.5 Imperial Valley	Yes	Yes	Yes	Yes
1980 M6.3 Victoria	Yes	Yes	Yes	Yes
1981 M5.9 Westmorland	Yes	Yes	Yes	Yes
1983 M7.7 Nihonkai-Chubu	No	No	Yes	Yes
1983 M6.8 Nihonkai-Chubu	No	No	Yes	Yes
1987 M6.5 Superstition Hills	Yes	Yes	Yes	Yes
1989 M6.9 Loma Prieta	Yes	Yes	Yes	Yes
1993 M7.6 Kushiro-Oki Hokkaido	No	No	Yes	Yes
1994 M6.7 Northridge	Yes	Yes	Yes	Yes
1994 M8.3 Toho-Oki Hokkaido	No	No	Yes	Yes
1995 M6.9 Kobe	Yes	Yes	Yes	Yes
1999 M7.5 Kocaeli	Yes	Yes	Yes	Yes
1999 M7.6 Chi-Chi	Yes	Yes	Yes	Yes
2000 M6.6 Tottori	Yes	Yes	Yes	Yes
2003 M8.3 Tokachi	No	No	Yes	Yes
2007 M6.8 Chuetsu-oki	Yes	Yes	Yes	Yes
2010 M7.2 El Mayor-Cucapah	Yes	Yes	Yes	Yes
2010 M7.0 Darfield	Yes	Yes	Yes	Yes
2010 M8.8 Maule	No	No	Yes	Yes
2011 M6.2 Christchurch	Yes	Yes	Yes	Yes
2011 M5.0 Christchurch	Yes	No	No	No
2011 M6.0 Christchurch	Yes	Yes	Yes	Yes
2011 M5.9 Lyttelton	Yes	Yes	Yes	Yes
2011 M9.1 Tohoku-Oki	No	No	Yes	Yes
2012 M6.1 Emilia	Yes	Yes	Yes	Yes
2012 M6.0 Emilia	Yes	Yes	Yes	Yes
2019 M7.06 Ridgecrest	Yes	Yes	Yes	Yes
2019 M6.48 Ridgecrest	Yes	Yes	Yes	Yes
2020 M7.0 Samos	Yes	Yes	Yes	Yes
2023 M7.81 Pazarcik	Yes	Yes	Yes	Yes
2023 M7.74 Kahramanmaras	Yes	Yes	Yes	Yes
2023 M6.81 Nurdagi	Yes	Yes	Yes	Yes
2023 M6.37 Yayladagi	Yes	Yes	Yes	Yes

Installation

Install the following Python libraries. Important: gmKriger currently requires the above specific pygmm commit.

pip install gmms geostats
pip install git+https://github.com/arkottke/pygmm@46403fd0a2c5ac1273e5837956971316360fa081
pip install gmKriger

How to use

Inputs

site:
Site ID(s) or site name(s).

latitude:
Site's latitude(s).

longitude:
Site's longitude(s).

Vs30:
Time-average shear-wave velocity in the top 30 m for the site(s).

earthquake:
Event from the available models (e.g., '1989 M6.9 Loma Prieta').

model:

• realizations: To use 1000 spatial correlation models.
  
• MAP: To use the maximum a posteriori spatial correlation model.
  gmim:
  Ground motion intensity measure from the available models (e.g., 'PGA').

Run

import gmKriger

site      = ['Alameda Naval Air Station', 'Treasure Island', 'Alameda Bay Farm Island', 'Farris Farm', 'POO7']
latitude  = [37.785748,37.8261394,37.73380567,36.91026828,37.805242]
longitude = [-122.309346,-122.3712351,-122.250101,-121.7437891,-122.339702]
Vs30      = [186.2,181.1,230.7,209.5,223]

earthquake = '1989 M6.9 Loma Prieta'
model      = 'realizations'
gmim       = 'PGA'

gmKriger.get_Kgmim(site,latitude,longitude,Vs30,earthquake,model,gmim)

Site	Lat (deg)	Lon (deg)	PGA (g)	sigma_PGA (ln)
Alameda Bay Farm Island	37.734	-122.250	0.151	0.396
Alameda Naval Air Station	37.786	-122.309	0.204	0.294
Farris Farm	36.910	-121.744	0.350	0.350
POO7	37.805	-122.340	0.152	0.322
Treasure Island	37.826	-122.371	0.133	0.250

Examples

• Example 1: Compute PGAs for the 1989 Loma Prieta Earthquake using all the 1000 spatial correlation models. here.
• Example 2: Cython backend. Compute PGA, PGV, Ia, and CAV for the 1989 Loma Prieta Earthquake using 1000 spatial correlation models. here.
• Example 3: Python backend. Compute PGA, PGV, Ia, and CAV for the 1989 Loma Prieta Earthquake using 1000 spatial correlation models. here.
• Example 4: Compute PGA, PGV, Ia, and CAV for the 2023 M7.8 Pazarcik Earthquake using the maximum a posteriori spatial correlation model. here.
• Example 5: Compute PGA, PGV, Ia, and CAV for the 1987 M6.5 Superstition Hills Earthquake all the 1000 spatial correlation models. here.

Acknowledgements

Albert R. Kottke kindly allowed modifications to the pygmm NGAWest2 GMM implementations that benefit gmKriger. This is greatly appreciated.

Citation

Pretell, R., Brandenberg, S.J., and Stewart, J.P. (2026). gmKriger: A Kriging-based ground motion intensity measure calculator (1.1.1). Zenodo. https://doi.org/10.5281/zenodo.10399418

Relevant publications

Pretell, R., Brandenberg, S.J., and Stewart, J.P. (2026). “Ground motion intensity measures at liquefaction field case history sites.” *Journal of Geotechnical and Geoenvironmental Engineering. 10.1061/JGGEFK/GTENG-14212 (In Press).

Pretell, R., Brandenberg, S.J., Stewart, J.P. (2024). Ground motion intensity measures at liquefaction field case history sites. Report submitted to CALTRANS. GIRS-2024-02. http://doi.org/10.34948/N35K59

Pretell, R., Brandenberg, S.J., Stewart, J.P. (2024). "Consistent framework for PGA estimation at liquefaction case history sites: Application to the 1989 M6.9 Loma Prieta Earthquake." In: Proceedings of Geo-Congress 2024, Vancouver, Canada, Feb. 25-28, 2024. https://doi.org/10.1061/9780784485316.018

Dataset

Pretell, R., Brandenberg, S., and Stewart, J. (2026). "Consistently computed ground motion intensity measures for liquefaction triggering assessment." DesignSafe-CI. https://doi.org/10.17603/ds2-6vj1-t096 v3

Contact

For any questions or comments, contact Renmin Pretell (rpretell at unr.edu).