Sc. Stiros et al., THE 1953 EARTHQUAKE IN CEPHALONIA (WESTERN HELLENIC ARC) - COASTAL UPLIFT AND HALOTECTONIC FAULTING, Geophysical journal international, 117(3), 1994, pp. 834
Geomorphological, marine biological and radiometric data in combinatio
n with earlier reports reveal that the M(s)=7.2, 1953 Cephalonia earth
quake, the most destructive but least studied earthquake in Greece thi
s century, was associated with a 0.3-0.7 m quasi-rigid-body uplift and
westward tilting of the central part of the island. Another palaeosei
smic event, around 1500 yr BP, associated with coastal uplifts was als
o identified. Structural data indicate that the 1953 uplift is bounded
by two subparallel, east-dipping major reverse faults and corresponds
to a piston-like motion. This structurally unusual pattern of seismic
deformation is detached from the deformation of the basement (conspic
uously a thrust) and different from the long-term deformation pattern
of the area; it is probably due to the particularities of salt tectoni
cs: a approximately 1500 m thick salt layer acts as a regional decolle
ment, while thinner layers are sandwiched between the carbonate thrust
sheets that compose the overburden and reduce their friction during f
ault movement. This crustal anisotropy is responsible for the observed
anomalous attenuation of seismic waves during the 1953 and historical
earthquakes. The 1953 seismic surface deformation mimics long-term ha
lotectonic patterns, but is not directly indicative of the regional st
ress-field, for it reflects uplift-induced stresses only.