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, http://doi.org/10.32858/temblor.143
 

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.