The viscosity distribution in the Aegean
Abstract
We investigate the distribution of effective viscosity within the Aegean, treating the continental lithosphere as a thin viscous sheet. Using observed strain rates and an assumed power law rheology as a proxy for stress, and topography and the geoid as proxies for gravitational potential energy, we invert for the vertically averaged effective viscosity. The lithospheric structure and heat flow distribution in the Aegean is very different to that of the deforming continental lithosphere in south east Asia. However, in comparison with previous studies of effective viscosity in deforming Asia, we find that effective viscosity in the Aegean also lies in the range (1022) to (1023) Pa s. This result presents a paradox with regard to models that predict the effective viscosity of the lithosphere to depend solely upon temperature structure. An alternative view, which can account for temperature insensitivity by postulating that the strength of the lithosphere resides entirely within the seismogenic upper crust, is unable to explain either the magnitude of strength differences or their distribution.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA....12008W