New constraints on the rapid crustal motion of the Aegean region: recent results inferred from GPS measurements (1993-1998) across the West Hellenic Arc, Greece
M. Cocard et al., New constraints on the rapid crustal motion of the Aegean region: recent results inferred from GPS measurements (1993-1998) across the West Hellenic Arc, Greece, EARTH PLAN, 172(1-2), 1999, pp. 39-47
In this paper we present the most recent observations of crustal motion acr
oss the entire West Hellenic Are (WHA). These are based on repeated GPS mea
surements carried out in the period from 1993 to 1998. The results are pres
ented in terms of trajectories and rates, relative to Eurasia. Within these
five years southwestern Greece has moved to the southwest by an average ra
te of 30 mm/a, increasing from 10 mm/a at the island of Lefkada, in the cen
ter of the Ionian islands, to nearly 40 mm/a along the southwest part of th
e Peloponnesus and to 35 mm/a on the islands of Crete and Gavdhos. The data
provide strong evidence that distributed shear strain starts at the Kephal
onia Fault Zone (KFZ), were an anomalously high earthquake activity is also
observed. A striking interruption of the motion is seen at the island of S
trofades, at the southwest leading edge of the WHA, where a south-oriented
displacement of 12 cm was detected, coincident with the M = 6.4 Strofades e
arthquake of Nov. 18, 1997. (C) 1999 Elsevier Science B.V. All rights reser
ved.