Convergence vs. retreat in Southern Tyrrhenian Sea: Insights from kinematics

The Tyrrhenian Sea is an extensional basin opened by
trench retreat and back-arc extension during subduction of
the Calabrian slab in the last 10–12 My. Subduction is still
active beneath the SEmost part of the Tyrrhenian Sea, as
testified by seismicity down to 500 km depth. By analyzing
seismicity and geodetic data, together with recent
tomographic images, we define the present-day situation.
An evident N-S compressional regime prevails in the
Tyrrhenian region west of the Aeolian archipelago, while
east of them a NNW-SSE extension is documented by focal
mechanisms and GPS data, with a much smaller strain rate
with respect to the past. The transition between these two
domains is accommodated by a N-S discontinuity zone
which runs from Aeolian Islands to Mt. Etna with an
extensional to strike-slip deformation.

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