Estimating the earthquake occurrence rates in Corinth Gulf (Greece) through Markovian arrival process modeling

ABSTRACT

The Markovian Arrival Process (MAP) is applied as a candidate model to describe the time-varying earthquake activity in Corinth Gulf, Greece. To the best of our knowledge, this is the first attempt to study the earthquake temporal evolution with the specific class of MAPs. A complete catalogue is used for the earthquake temporal distribution investigation, along with data sets of different magnitude cutoffs. The study area is divided into its western and eastern subareas, and possible variations in the earthquake occurrence times were sought. Hidden states of MAPs correspond to different levels of seismicity, and hence various numbers of states are examined. Akaike and Bayes information criteria are implemented for identifying the best model, and comparison to the most known and broadly accepted theoretical interevent time distributions is provided. In all cases, the fitted MAPs with phase type distributed intearrival times outperform the models with other distributions. Important indicators of the underlying Markov process are computed, and the earthquake frequency is approximated by the counting process. The analysis demonstrates high index of burstiness for the earthquake generation in the eastern part, i.e. long quiescent periods alternate with short ones of intense seismic activity.

KEYWORDS:

• Markov arrival process
• earthquake occurrence rates
• background seismic activity
• Corinth Gulf
• EM algorithm

2010 MATHEMATICS SUBJECT CLASSIFICATIONS:

• 60J28
• 62M05
• 86A15

Acknowledgements

The constructive comments of three reviewers and editorial assistance of Prof. Jie Chen are acknowledged for their contribution to the improvement of the paper. The software Generic Mapping Tools was used to plot the map of the study area (Wessel and Smith [50]). Geophysics Department Contribution 911.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the European Union and Greece (Partnership Agreement for the Development Framework 2014–2020) under the Regional Operational Programme Ionian Islands 2014–2020, for the project “Telemachus - Innovative Operational Seismic Risk Management System in the Region of Ionian Islands” [grant number 80306].