The seismicity of the last 15 years in the Aegean Sea revealed that earthquakes (<i>M</i>_w > 5) with epicentres falling within the Sporades basin and the confined area north of Samos island were preceded by electric seismic signals (SES) with a remarkably long lead time. A possible explanation of this behaviour by means of specific tectonics and geodynamics which characterise these two regions, such as a significant small crustal thickness and a high heat flow rate, has been attempted. New data seem to strengthen the above hypothesis.