AN ANALOG EXPERIMENT FOR THE AEGEAN TO DESCRIBE THE CONTRIBUTION OF GRAVITATIONAL POTENTIAL-ENERGY

The southern Aegean seafloor exhibits clear evidence of internal defor mation (stretching) as shown by tectonics, seismology and space geodes y. We use an analog three-layer laboratory experiment of sand, silicon e putty and honey to investigate the deformation of the southern Aegea n lithosphere. The model is installed in a box and confined by a verti cal wall. We open a gate in the wall and observe the deformation of th e two upper layers due to buoyancy forces. The general pattern of the deformation of the southern Aegean is found in the analog model. We ob serve the formation of an are spreading outward with time, the extensi on is radial in the inner part, but parallel to the are in the externa l part and of comparable importance. At both ends of the gate we obser ve strike-slip motion (dextral in the western part, sinistral in the e astern part). Rotation (clockwise in the western part, counterclockwis e in the eastern part) of up to 40 degrees is seen on both sides of th e gate but is also present, with a smaller amplitude, far in the inter nal region, partially due to distributed shear. The spreading is assoc iated with the thinning of the two upper layers and affects a region o f dimensions comparable to the length of the free boundary. This sprea ding does not propagate inward with time. Some pieces of material loca ted near the active boundary remain undeformed during the experiment.