Seismic anisotropy reveals focused mantle flow around the Calabrian slab (Southern Italy)

Publication Type: 
Year of Publication: 
2007
Journal Title: 
Geophysical Research Letters
Journal Date: 
Mar 3
Volume: 
34
Issue: 
5
Pages: 
-
ISBN Number: 
0094-8276
Accession Number: 
ISI:000244707400005
Abstract: 

SKS splitting at the Calabrian subduction zone, with delay times (delta t) up to 3s, reveals the presence of a strong anisotropic fabric. Fast directions (phi) are oriented NNE-SSW in the Calabrian Arc ( C. A.) and rotate NNW-SSE to the north following the arcuate shape of the subducting plate. We interpret the trench-parallel phi as local-scale mantle flow driven by the retrograde motion of the slab; the absence of trench perpendicular f below the Southern Apennines (S. A.) excludes the presence of a seismically detectable return flow at its NE edge. This may be due to the relative youth and limited width of the S. A. slab tear. A possible return flow is identified farther north at the boundary of the S. A. and Central Apennines. Different and weaker anisotropy is present below the Apulian Platform ( A. P.). This implies that the influence of the slab rollback in the sub-slab mantle is limited to less then 100 km from the slab.

Notes: 

143GFTimes Cited:5Cited References Count:33

DOI: 
Doi 10.1029/2006gl028899