Statistical Analysis of the Inter-Event Time, Distance, and Migrating Trend Distribution of Successive Large Earthquakes in Iran

Document Type : Research Article

Author

School of Earth Sciences, Damghan University, Damghan

Abstract

In this study, the waiting time, spatial distance, and migrating trend pattern of
successive large earthquakes in Iran have been investigated. In order to carry out
this work, the earthquake data of Iran with M >= 4.5 (1976-2018) have been
obtained from the USGS catalog. Then, the statistical distribution of the Interevent
time, migrating distance, and directional trend of migration of successive
events were studied using different lower magnitude thresholds. The statistical and
probability distributions of inter-event times of earthquakes were assessed and
modelled by different distribution models. Furthermore, the directional analysis
of migrating trends, as well as the spatial distances of successive events with
different lower magnitude, was carried out. It is observed that the inter-event time
distribution of earthquakes can be quite well fitted by the Gamma distribution
model. The results obtained also indicate a decreasing trend in spatial distance
distribution and a meaningful correlation between the directional pattern of the
migrating trends of successive events and the dominant trends of the active faults of
the region. The results of this study can be considered as an effective step to better
understanding the temporal-spatial pattern of seismicity in Iran and also as an
attempt to achieve earthquake prediction in this country, in a regional scale.

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