Abstract:
The Hindukush region is renowned for its high seismic activity, making it a crucial area for
earthquake analysis. This research examines the earthquake data from 2008 to 2010 utilizing
sophisticated statistical techniques. The earthquake catalog contains both dependent and inde
pendent events, required declustering to eliminate dependent events. The study focuses declus
tering methods with the Gardner-Knopoff approach to identify mainshocks. The declustering
found 3164 clusters of earthquakes with a total of 3574 (37.5 %) events out of 9532 with only
the mainshock shown on a color-coded seismicity map. The Gutenberg-Richter relationship
was used to assess the distribution of magnitudes, indicating a completeness magnitude of Mc
= 3.03. Temporal and spatial analyses revealed a high productivity rate “a” of 5.21, indicating
significant seismic activity, and “b” value of 0.98, reflecting notable higher frequency of smaller
earthquakes. Variations in b-values were linked to the region’s distribution of earthquake mag
nitudes, while the high “a” value was due to elevated seismic activity. Moreover, the research
employed the ETAS model to distinguish between background and triggered seismic activity
in a defined area, identifying 146 target events and classifying 75% as background events. Us
ing an iterative stochastic declustering method, the ETAS model yielded Maximum Likelihood
estimates for important parameters, emphasizing the connection between mainshocks and af
tershocks. The plot of estimates of ETAS model and spatial and temporal plots were utilized
providing valuable information for assessing seismic hazard and evaluate the model’s accuracy.
This research provides crucial insights on earthquake risks in the Hindukush area, enhancing
earthquake assessment and risk analysis.
