Earthquake Diffusion Variations in the Western Gulf of Corinth (Greece)

Spatiotemporal Properties of Seismicity and Variations of Shear-Wave Splitting Parameters in the Western Gulf of Corinth (Greece)

“…In terms of the Continuous Time Random Walk (CTRW) model (e.g., [55]), this value of the power-law exponent indicates super-diffusion. Compared to the range of exponents reported in the literature that mainly correspond to slow earthquake sub-diffusion [49,[56][57][58][59][60], the diffusion exponent in this case is significantly larger and comparable to that reported by [61]. Hence, the large diffusion exponent likely corresponds to large rates of earthquake migration triggered by aseismic factors, such as pore-pressure diffusion or aseismic creep.…”

“…Numerical simulations of fluid transport in heterogeneous fault zones also show anomalous diffusion with exponents greater than 1, as fluid flow is channeled in fractal fault zones with varying permeabilities [69]. In contrast, stress transfer effects due to subcritical crack growth or to cascading effects yield quite low diffusion exponents and sub-diffusion [57,58], most commonly observed in earthquake diffusion [49,60]. The super-diffusive behavior of seismicity reported herein may, thus, provide an additional indication of fluid overpressures.…”

“…S1: Absolute location error and other statistics per spatial group (see Figure 2) for the seismicity of 2013-2014 (Catalogue 1) in the Western Gulf of Corinth (WGoC). Table after [60], Table S2: Statistics of the station jack-knife test for the relocation robustness per spatial group of the 2013-2014 seismicity in the WGoC, with dx, dy and dz values representing perturbations from the true relocated hypocenter. The 95% confidence interval ellipse major semi-axis length refers to the horizontal ellipses of Figure S2, as estimated for each whole spatial group, Table S3: Mean values of SWS parameters and their respective errors per station for valid measurements (grade A-C) of Catalogue 3.…”

“…The msd shows a step-like increase with time that can be approximated, overall, by a power-law function, with a diffusion exponent of a = 1.81 ± 0.17 that indicates super-diffusion. [60] studied separately the distinct seismic clusters occurring in the spatial groups #4, #6 and #8 (e.g., Figures A1, A3 and A4 in Appendix A), yielding diffusion exponents lower than 0.2 and sub-diffusion. However, herein we observe that if the seismic clusters are jointly studied on a larger scale, a much faster diffusive process is obtained that spans from the Rion strait in the west to offshore Aigion in the east (Figure 4, top).…”

Identification and Temporal Characteristics of Earthquake Clusters in Selected Areas in Greece

“…One of the major detected sequences is the 2013 Aigion swarm (C6 in Figure 4b) which initiated on 21 May 2013 with a bulk of small events and several bursts associated to earthquakes with magnitudes ranging between 3.3-3.7 (Figure S3) [63,64]. Two distinct excitations followed (C8 and C10 in Figure 4b) in accordance with the ones observed by Michas et al [65]. The first cluster began on 7 July with some activity prior to the M = 3.7 event on 15 July 2013, and lasted until 27 August, 2013 (Figure S3).…”