Surface deformation observed in moderate Greek quake

By Sotiris Valkaniotis, Ph.D., Koronidos Str., Greece and Athanassios Ganas, Ph.D., National Observatory of Athens, Institute of Geodynamics

Citation: Valkaniotis, S., and Ganas, A., 2020, Surface deformation observed in moderate Greek quake, Temblor,

For the first time in Greece, satellite radar imagery has revealed surface deformation due to an earthquake as small as magnitude-4.6. The earthquake occurred on Dec. 2, 50 km northwest of Athens, where it was widely felt. Analysis by Sotiris Valkaniotis and Athanassios Ganas.


The earthquake ruptured a shallow portion of the SW-dipping Kallithea Fault. The National Observatory of Athens (NOA) epicenter appears slightly mislocated, whereas the Aristotle University of Thessaloniki (AUTH) location looks better.

In the right panel, one sees 6 cm (2.3 in) of subsidence of the downthrown side of the fault, but almost no uplift on the upthrown side, which is expected of a tensional earthquake on a fault dipping about 45°.

Basins like the one on the downthrown block form over the eons, through repeated earthquakes, such as last week’s magnitude-4.6.