Earthquake diffusion and the migration behaviour of seismic clusters are commonly studied to provide insight on the spatiotemporal evolution of seismicity and the interplaying driving mechanisms. Using a high-resolution relocated catalogue, we study the variations of the earthquake diffusion rates in the Western Gulf of Corinth during 2013–2014, a period with abundant local seismicity, including intense microseismic background, seismic swarms and mainshock-aftershock sequences. We treat earthquake occurrence as a point process in time and space and estimate the diffusion rates of the main seismic sequences and the background seismicity in terms of normalized spatial histograms and the evolutions of the mean squared distance of seismicity with time. The statistical analysis of the studied seismic sequences reveals that the mean squared distance of the hypocentres increases slowly with time, at a much lower rate than for a normal diffusion process. Such findings confirm previous results on weak earthquake diffusion, analogous to subdiffusion, in regional and clustered seismicity. In addition, seismic swarms associated with pore fluid pressure diffusion present considerably higher diffusion exponents compared to mainshock-aftershock-type sequences that are consistent with primary or secondary stress triggering effects and stress corrosion. The observed variations of the earthquake diffusion rates indicate the stochastic nature of the phenomenon and may provide novel constraints on the triggering mechanisms of clustered seismic activity in the Western Gulf of Corinth and in other seismically active regions.

地震扩散和地震群的迁移行为通常被研究，以提供对地震活动时空演化和相互作用驱动机制的深入了解。使用高分辨率重定位目录，我们研究了 2013-2014 年科林斯湾西部地震扩散率的变化，这是一个具有丰富局部地震活动的时期，包括强烈的微地震背景、地震群和主震-余震序列。我们将地震发生视为时间和空间上的一个点过程，并根据归一化的空间直方图和地震活动均方距离随时间的演变来估计主要地震序列和背景地震活动的扩散速率。对所研究地震序列的统计分析表明，震源的均方距离随时间缓慢增加，其速度远低于正常扩散过程。这些发现证实了先前在区域和集群地震活动中类似于亚扩散的弱地震扩散的结果。此外，与主震-余震型序列相比，与孔隙流体压力扩散相关的地震群表现出相当高的扩散指数，这与一次或二次应力触发效应和应力腐蚀相一致。