Spatio-Temporal Analysis of Strain and Seismicity in Kalimantan: Insights into Regional Seismic Hazard Potential Yuliastuti, Irwan Meilano, Nanang T. Puspito, Susilo
Institut Teknologi Bandung
Badan Riset dan Inovasi Nasional
Abstract
This study examines the spatio-temporal correlation between seismicity and strain-rate models in Kalimantan. The analysis aims to elucidate patterns of earthquake occurrence by investigating processes of earthquake loading and unloading. Strain-rate data were obtained from 85 continuous GPS observation stations, while seismicity data comprised relocated earthquakes from 1905 to 2022. The strain-seismicity correlation was calculated by comparing cumulative geodetic potency rates with seismicity counts. Spatial analysis revealed that 50% of the regions with the highest strain rates account for 80.56% of the recorded M>=6 earthquakes, indicating a strong correlation between strain rate and seismicity. This relationship suggests the potential of strain rates as effective predictors of seismic activity. For temporal analysis, seismicity data were segmented into several periods: 1957-1967, 1968-1978, 1979-1989, 1990-2000 and 2001-2022. During the 1957-1967 period, the seismicity curve was significantly below the potency-rate curve, indicating a diffused pattern characterized as the accumulation phase. In contrast, the 1968-1978 period showed the seismicity curve approaching the potency-rate curve, suggesting a transition to the localization phase where seismic activity became more concentrated in high strain-rate areas. The 1979-1989 period showed the seismicity curve substantially above the potency-rate curve, indicating that earthquakes predominantly occurred in high strain-rate zones, corresponding to the rupture phase. These findings provide valuable insights into the spatio-temporal dynamics of seismicity in Kalimantan, with implications for regional seismic hazard assessment.
