E3S Web of Conferences (Jan 2023)

Temporal Change and Spatial Distribution Analysis of b-value and a-value in Sumatra

  • Khalqillah Aulia,
  • Umar Muksin

DOI
https://doi.org/10.1051/e3sconf/202344701016
Journal volume & issue
Vol. 447
p. 01016

Abstract

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The study of seismicity is very important to be conducted in the region of interest, such as Sumatra which has high seismicity. The seismicity can be learned by using a statistical approach through the b-value and a-value parameters. The b-value describes the stress accumulation of rock while the a-value describes the seismic activity. The objective of this research is to analyse the temporal change and spatial distribution seismicity based on b-value and a-value parameters in Sumatra by using an updated earthquake catalog from 1964 to 2022. This research found that in 1965 and 1972 have b-values greater than 2 temporally. In the spatial distribution analysis, Sumatra was dominated by b-value less than 1.91. Six clusters were found to have the lowest b-value. It might indicate high seismic stress accumulation spatially in these clusters. The temporal change and spatial distribution analysis were validated by using four destructive earthquakes in Sumatra, such as Sumatra-Andaman, Nias-Simeulue, Mentawai, and Pasaman Barat earthquakes. The b-values were found to be less than 1 either temporally or spatially. The large earthquake was confirmed to have a low b-value. This indicates high seismic stress accumulation. These results can be used for further seismic hazard analysis and decision support for disaster mitigation purposes.