Page 9 - 05 albarello

Finite element modelling of the recent-present deformation pattern in the Calabrian are and surrounding regions

A tentative elastic parametrization of defor- estimate of tectonic forces, both concerning
mation belts has been carried out by a trial and modulus and orientation. Along sectors I, II
errar procedure, to obtain strain rates ranging and III of the external border (fig. 4) only mo-
tions parallel to the boundary are allowed.
w- w-between 13 and 15 s-1, which can be con- These conditions try to simulate the present
time very low mobility of the Adriatic and
sidered realistic values for this kind of zones Corsica Sardinia block with respect to stable
(Sibson and Ramsay, 1982; Sibson, 1984; Eurasia (Mantovani et al., 1996, 1997).
Smith and Bruhn, 1984; Williarns and Richard-
son, 1991). 4. Main results

The external boundaries of the mesh have Figures 5 and 6 show the displacement and
been assumed to be far enough from the stud- strain fields obtained by imposing a N20°E dis-
ied area (fig. 4) so that edge effects can be placement of l m along sectors IV, V and VI
ignored. of the external border (fig. 4). This dispiace-

We preferred to impose kinematic boundary
conditions rather than boundary forces since
we be1ieve that the uncertainty on motion rates
is much lower than that which may affect the

l

1

t1-->

!!

l 11

! l!
! 11
! 11

1 1r
r rr
1 r r 11 11

llllll l

Fig. 5. Displacement field resulting from numerica! modelling by imposing a l m displacement of Africa
along a N20°E direction. The scale of displacements (arrows) is reported in the inset. Geographical contours
and geometry of structural domains (fig. 4) are reported for reference. North is upward.

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