2026-10-06T07:10:43Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34054314 2026-10-02T05:33:21Z category_143 portal_316 item_type_3 month_year_10_2026

Data Sheet 1_Imaging the shear deformation zone along the Kefalonia transform fault zone.docx V. Anagnostou (25162359) E. Papadimitriou (25162362) V. Karakostas (11497870) Solid Earth Sciences Kefalonia fault Kefalonia transform fault zone KTFZ Lefkada fault principal component analysis relocated seismicity shear deformation zone <p>We quantify the three-dimensional geometry and the across-fault width of the seismically active shear deformation zone of the segments ruptured by large (M > 6.0) strike-slip main shocks of the Kefalonia Transform Fault Zone (KTFZ), the 2014 Kefalonia doublet and the 2015 Lefkada earthquake. Using high-resolution relocated aftershock seismicity for these sequences (1154 earthquakes, M 1.4–6.1, and 1291 earthquakes, M 0.2–6.5, respectively) and following the approach of Perrin et al. (2021), we estimate local best-fitting fault planes in moving windows along strike using principal component analysis (PCA), measure hypocentral distances orthogonal to each plane, and stack the normalized fault-normal distance profiles to determine the characteristic inner and outer bounds of the active shear zone (W_S1 and W_S2). A regularized power-law function is fitted to the stacked distribution, marking W_S1 at the distance of maximum curvature, and W_S2 at the distance where the distribution departs from the power law. The two sequences yield W_S1 values of 0.83 km for the Kefalonia and 0.50 km for the Lefkada sequences and W_S2 values of 1.88 km and 1.49 km, respectively. Assuming approximate symmetry around the local best-fitting plane, these correspond to full active shear-zone widths of about 3.8 and 3.0 km, respectively. Map-view traces of the local PCA-derived fault patches reveal coherent principal fault orientations together with oblique secondary alignments. These orientations are consistent with earlier interpretations of a segmented dextral transform zone containing relay and transfer structures. The results provide a reproducible, seismicity-based framework for characterizing active shear-zone width, segmentation, and secondary-fault activation along the most seismically hazardous strike-slip system in the eastern Mediterranean.</p> 2026-10-02T05:33:21Z Dataset Dataset 10.3389/feart.2026.1939552.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Imaging_the_shear_deformation_zone_along_the_Kefalonia_transform_fault_zone_docx/34054314 CC BY 4.0