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Surface imprint of toroidal flow at retreating slab edges: The first geodetic evidence in the Calabrian subduction system
Author(s) -
Palano M.,
Piromallo C.,
Chiarabba C.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl071452
Subject(s) - geology , slab , clockwise , subduction , seismology , lithosphere , tearing , mantle (geology) , toroid , slab window , geodetic datum , geophysics , geodesy , tectonics , rotation (mathematics) , geometry , physics , oceanic crust , mathematics , plasma , quantum mechanics , thermodynamics
Dense GPS observations can help Earth scientists to capture the surface imprint of mantle toroidal flow at slab edges. We document this process in the Calabrian subduction system, where the Ionian slab rollback took place during the past 30 Ma, following a stepwise process driven by migration of lithospheric tearing. We found rotation rates of ~1.29°/Ma (counterclockwise) and ~1.74°/Ma (clockwise), for poles located close to the northern and southern slab edges, respectively. These small‐scale, opposite rotations occur along complex sets of active faults representing the present‐day lithospheric expression of the tearing processes affecting the southeastward retreating Ionian slab at both edges. The observed rotations are likely still young and the process more immature at the northern tear, where it is unable to reorient mantle fabric and therefore is unseen by SKS splitting.