# Seismic Hazard Evaluation and Strain Dynamics in the
## 4 Discussion and Findings
### Strain Accumulation and Evaluation of \(a\) and \(b\) Parameters  
The \(a\) and \(b\) parameters, which are associated with the physics of earthquake occurrence, the tectonics of the region, and the total seismic activity, were determined specifically for the SFZ as \(a\) = 6.33 and \(b\) = 0.92 (Figure 5). The _a_-value, which characterizes the degree of seismic activity or indicates the total seismic activity level of the studied region, was classified by [PERSON] [120] as low seismic activity if it is less than six. However, subsequent studies have shown that the _a_-value is directly related to the size of the region under investigation, the time period considered, and the catalog used. It has also been emphasized that the _a_-value may reflect different seismic activity levels for each region. In general, a value between three and four indicates low seismic activity in the region, a value between four and six suggests moderate seismic activity, and a value greater than six indicates high seismic activity. In various studies conducted for different regions of the world, _a_-values have been estimated using different methods. On a global scale, the _a_-value has been calculated  
Figure 10: Segment-based strain rates calculated for the SFZ (red lines represent active faults in the region, blue arrows indicate extension, and black arrows denote compression, black lines extending from top to bottom represent Sindrig segment, Simav segment, Saphane segment, Abide segment, Banaz segment, Elvanpasa segment, and Sinapasa segment, from west to east, respectively. as 5.65 to 7.23 in oceanic subduction zones, 6.83 to 8.37 in mid-ocean ridges, 6.11 for the San Andreas Fault, and 6.37 for the Bitlis-Zagros collision zone [89]. In another study focusing on the EAFZ, another significant tectonic feature of the Anatolian Plate, the \(a\)-values for the Palu-Hazar Lake segment were estimated to range between 6.5 and 7.0. This suggests that the region is seismically more active than other segments of the EAFZ [94]. In a separate study examining the East African Rift System, a different continental plate, the study area was divided into seven regions, and the \(a\)-values were found to vary between 3.78 and 8.4. An \(a\)-value of 5.75 was calculated for the Afar Triple Junction, which the authors identified as a highly seismically active region [121]. The \(a\)-value obtained in this study indicates that the SFZ and its surrounding area have an active seismic structure and indicate intense earthquake activity. Additionally, a significant number of small-to-moderate magnitude earthquakes that occurred in the region during the studied time period further validate the high \(a\)-value obtained (Figure 2). According to [PERSON] and [PERSON] [122], regions with low crustal heterogeneity and stress are associated with \(b\)-values greater than 1.0, while values less than 1.0 are related to high differential stresses. A high \(b\)-value indicates that small earthquakes dominate in the studied region, while a low \(b\)-value suggests that larger earthquakes suppress smaller events in that area. In addition, it has been stated by many researchers that the \(b\)-value is related to the Earth's crustal stress. Regions or faults with high stress rates and large deformation velocities tend to have lower \(b\)-values, while areas with low stress accumulation exhibit higher \(b\)-values [94; 104; 120; 123; 124; 125]. The results obtained from this study, which present findings related to the region's strain rates, have been compared with conducted studies in the literature. In studies where Western Anatolia is generally considered as a whole, with no specific focus on the SFZ, [PERSON] [126], [PERSON] et al. [127], and [PERSON] [128] found the \(a\)-values to range between 4.4 and 5.4, and the \(b\)-values to range between 0.52 and 0.88, within a source zone that includes some part of the SFZ. [PERSON] and [PERSON] [129] calculated the \(a\) parameter as 3.82 and b parameter as 0.8, [PERSON] et al.