The Cephalonia Transform Fault and its extension to western Lefkada Island (Greece)

The central area of the Ionian Islands is dominated by the existence of a major tectonic structure called the Cephalonia Transform Fault (CTF). Its main part (Cephalonia segment) has been identified by previous work based on the spatial distribution of earthquake foci, fault plane solutions of strong earthquakes, active tectonics, structural studies and geodetic measurements. This part (Cephalonia segment) which exhibits strike-slip motion with a thrust component, strikes in a northeast direction, dips to the southeast and has a length of ∼90 km. In the present paper information concerning new fault plane solutions, orientation of isoseismals, sea bottom topography and recent GPS results are used to further check the properties of this southern part of the CTF and to explore its northeastward prolongation to Lefkada Island. It is shown that the CTF is extended to the western coast of Lefkada. This northern branch (Lefkada segment) of the CTF which is also characterized by strike-slip motion with a thrust component, strikes in a north-northeast direction, dips to the east-southeast and has a length of ∼40 km. These two segments of the CTF form a major kinematic boundary where the slip rate is 2–3 cm/yr.

[1]  D. Sorel.  L'évolution structurale de la Grèce nord-occidentale depuis le miocène, dans le cadre géodynamique de l'arc égéen , 1989 .

[2]  C. Papazachos,et al.  A formulation for reliable estimation of active crustal deformation and its application to central Greece , 1992 .

[3]  I. Finetti,et al.  Geophysical Exploration of the Mediterranean Sea , 1973 .

[4]  Walter I. Futterman,et al.  Dispersive body waves , 1962 .

[5]  M. Crespi,et al.  Repeated GPS surveys across the Ionian Sea: evidence of crustal deformations , 1996 .

[6]  G. Danuser,et al.  The strain field in northwestern Greece and the Ionian Islands: results inferred from GPS measurements , 1995 .

[7]  C. Papazachos.  Anisotropic radiation modelling of macroseismic intensities for estimation of the attenuation structure of the upper crust in Greece , 1992 .

[8]  Paul G. Richards,et al.  Quantitative Seismology: Theory and Methods , 1980 .

[9]  B. Papazachos.  Seismicity of the Aegean and surrounding area , 1990 .

[10]  Panayotis Papadimitriou.  Etude de la structure du manteau supérieur de l'Europe et modélisation des ondes de volume engendrées des séismes égéens , 1988 .

[11]  H. Lyon‐Caen,et al.  Earthquake mechanisms of the Adriatic Sea and Western Greece: implications for the oceanic subduction-continental collision transition , 1997 .

[12]  D. Panagiotopoulos,et al.  Evidence for transform faulting in the Ionian sea: The Cephalonia island earthquake sequence of 1983 , 1985 .

[13]  X. Pichon,et al.  The hellenic arc and trench system: A key to the neotectonic evolution of the eastern mediterranean area , 1979 .

[14]  Anastasia Kiratzi,et al.  Fault plane solutions in the Aegean sea and the surrounding area and their tectonic implication , 1998 .

[15]  S. Stiros,et al.  The 1953 earthquake in Cephalonia (Western Hellenic Arc): coastal uplift and halotectonic faulting , 1994 .

[16]  Geoffrey C. P. King,et al.  The landscape geometry and active tectonics of northwest Greece , 1993 .

[17]  W. Ryan,et al.  Plate Tectonics and the Evolution of the Alpine System , 1973 .

[18]  E. Papadimitriou,et al.  Regional focal mechanisms for earthquakes in the Aegean area , 1991 .

[19]  C. Langston,et al.  Moment tensor inversion of the 1983 January 17 Kefallinia event of Ionian islands (Greece) , 1991 .

[20]  P. Molnar,et al.  Fault plane solutions of earthquakes and active tectonics of the Tibetan Plateau and its margins , 1989 .

[21]  D. McKenzie.  Active tectonics of the Alpine—Himalayan belt: the Aegean Sea and surrounding regions , 1978 .

[22]  J. Underhill.  Late Cenozoic deformation of the Hellenide foreland, western Greece , 1989 .

[23]  N. Kenyon,et al.  Evolving miogeanticlines of the East Mediterranean (Hellenic, Calabrian and Cyprus Outer Ridges) , 1977, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[24]  J. Nábělek,et al.  Earthquakes, gravity, and the origin of the Bali Basin: An example of a Nascent Continental Fold-and-Thrust Belt , 1987 .

[25]  K. Makropoulos,et al.  Microseimicity and strain pattern in northwestern Greece , 1995 .

[26]  X. Le Pichon,et al.  Geodetic determination of the kinematics of central Greece with respect to Europe: Implications for eastern Mediterranean tectonics , 1995 .

[27]  G. Veis,et al.  Trajectories of crustal deformation of western Greece from GPS observations 1989–1994 , 1996 .

[28]  S. Lallemant,et al.  La transition subduction-collision le long de l'Arc Egéen externe , 1985 .

[29]  H. Philip,et al.  La neotectonique plio-quaternaire de l'Arc egeen externe et de la mer Egee et ses relations avec la seismicite , 1976 .

[30]  D. Panagiotopoulos,et al.  Travel times of Pn -waves in the Aegean and surrounding area , 1985 .

[31]  Anastasia Kiratzi,et al.  A detailed study of the active crustal deformation in the Aegean and surrounding area , 1996 .

[32]  G. Veis,et al.  The Kephalonia Transform Fault and the rotation of the Apulian Platform: Evidence from satellite geodesy , 1993 .

[33]  James Jackson,et al.  Active tectonics of the north and central Aegean Sea , 1991 .

[34]  James Jackson,et al.  Active tectonics of the Adriatic Region , 1987 .