Declustering of Iran earthquake catalog (1983–2017) using the epidemic-type aftershock sequence (ETAS) model
The main goal of this article is to decluster Iranian plateau seismic catalog by the epidemic-type aftershock sequence (ETAS) model and compare the results with some older methods. For this purpose, Iranian plateau bounded in 24°–42°N and 43°–66°E is subdivided into three major tectonic zones: (1) North of Iran (2) Zagros (3) East of Iran. The extracted earthquake catalog had a total of 6034 earthquakes (Mw > 4) in the time span 1983–2017. The ETAS model is an accepted stochastic approach for seismic evaluation and declustering earthquake catalogs. However, this model has not yet been used to decluster the seismic catalog of Iran. Until now, traditional methods like the Gardner and Knopoff space–time window method and the Reasenberg link-based method have been used in most studies for declustering Iran earthquake catalog. Finally, the results of declustering by the ETAS model are compared with result of Gardner and Knopoff (Bull Seismol Soc Am 64(5):1363–1367, 1974), Uhrhammer (Earthq Notes 57(1):21, 1986), Gruenthal (pers. comm.) and Reasenberg (Geophys Res 90:5479–5495, 1985) declustering methods. The overall conclusion is difficult, but the results confirm the high ability of the ETAS model for declustering Iranian earthquake catalog. Use of the ETAS model is still in its early steps in Iranian seismological researches, and more parametric studies are needed.
KeywordsDeclustering Earthquake catalog Seismotectonic provinces of Iran Windowing methods ETAS model
Gardner and Knopoff
Epidemic-type aftershock sequence model
The authors acknowledge the funding support of Babol Noshirvani University of Technology through Grant No. BUT/388011/97. We wish to appreciate Mohammad Shahvar for his help in providing the earthquake catalog and magnitude conversation relations used in this article.
HRT proposed the initial idea and guided us in the analysis. ND analyzed the data completed all experiments and wrote the manuscript. MZ directed us to create a seismic catalog and seismic zoning. AJ developed the ETAS model code. All authors read and approved the final manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Amini H (2014) Comparing Reasenberg and Gruenthal declustering methods for north of Iran. In Second European conference on earthquake engineering and seismologyGoogle Scholar
- Gardner JK, Knopoff L (1974) Is the sequence of earthquakes in Southern California, with aftershocks removed, Poissonian? Bull Seismol Soc Am 64(5):1363–1367Google Scholar
- Gutenberg B, Richter CF (1944) Measurement error models. Bull Seismol Soc Am 34:185–188Google Scholar
- Jalilian A, Zhuang J (2016) ETAS: modeling earthquake data using ETAS model. R package version 0.2. https://CRAN.R-project.org/package=ETAS
- Uhrhammer R (1986) Characteristics of northern and central California seismicity. Earthq Notes 57(1):21Google Scholar
- Vere-Jones D (1970) Stochastic models for earthquake occurrence. J Roy Stat Soc: Ser B (Methodol) 32(1):1–62Google Scholar
- Wells DL, Coppersmith KJ (1994) New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement. Bull Seismol Soc Am 84(4):974–1002Google Scholar
- Zhuang J, Ogata Y, Vere-Jones D (2006) Diagnostic analysis of space-time branching processes for earthquakes. In: Baddeley A, Gregori P, Mateu J, Stoica R, Stoyan D (eds) Case Studies in Spatial Point Process Modeling. Lecture Notes in Statistics, vol 185. Springer. New York, NY, pp 275–292CrossRefGoogle Scholar