On the tectonic processes along the Hellenic Arc

A. G. GALANOPOULOS

Abstract


On the grounds of existing geophysical data one
might be allowed lo conclude t h a t the origin of t h e stress field in the Ionian
center (Ceplialonia-Zante-Patras) at t h e northwestern margin of the Aegean
microplate is r a t h e r shallow and in the southeastern center (Dodecanese-Crete)
is surely under the crust.
In the area occupied by the second center of higher earthquake activity
t h e relief of the Moho-discontinuity is shallower and smoother in comparison
to t h a t derived from g r a v i t y and seismic d a t a for t he area of t h e northwestern
center. Another difference derived from the fault-plane solutions is t h a t the
Ionian center is seated in a region of horizontal pressure; the second center in
the southeastern Aegean Sea belongs to a region of paramount horizontal
tension.
In the western side of the Hellenic arc the high sediment supply rate,
combined with a thickening of the E a r t h ' s crust along the Ionian zone, is
interpreted as evidence t h a t accretion has occurred there until recently or
may still be occurring locally; plate consumption, if any, is rather low.
The existence, 011 t h e other hand, of two very deep subparallel trenches
with little fill southeast of Crete (Pliny trench, Strabo trench), combined
with a very high subcrustal activity in the southeastern margin of t h e Aegean
Bubplate, suggest that the subduction rate at the northern boundary of the
African plate must be relatively high; 110 p l a t e accretion is expected to occur
there.

Full Text:

PDF

References


DOI: https://doi.org/10.4401/ag-4932
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it (Read more).
Ok


Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN: 2037-416X