Hi Alessandro,
Whether this method is reliable is still very much a matter of debate, 
but I will restrain from going into a long rant here. What I can tell 
you is that this is the standard implementation in the vast majority of 
dislocation models used to fit geodetic data. For example all standard 
block modeling codes that I know of use backslip to predict interseismic 
surface velocities and surface deformation patterns regardless of the 
type of faulting involved. E.g...

Becker, T. W., J. L. Hardebeck, and G. Anderson (2005), Constraints on 
fault slip rates of the southern California plate boundary from GSA 
velocity and stress inversions, Geophysical Journal International, 160, 
634-650.
Meade, B. J., and B. H. Hager (2005), Block models of crustal motion in 
Southern California constrained by GPS measurements, Journal of 
Geophysical Research, 110(B03403).
McCaffrey, R. (2005), Block kinematics of the Pacific-North America 
plate boundary in the southwestern United States from inversion of GPS, 
seismological, and geologic data, Journal of Geophysical Research, 
110(B07401).

I have even used something mathematically identical to backslip in my 
work on faulting in the tectonically complex Los Angeles, California region.

Marshall, S. T., M. L. Cooke, and S. E. Owen (2009), Interseismic 
deformation associated with three-dimensional faults in the greater Los 
Angeles region, California, Journal of Geophysical Research, 
114(B12403), 1-17.

As with all things in science, there are alternatives:
1) You may also look into doing strain inversions of the geodetic data 
to get strain rates. You can convert the infinitesimal strain rate 
tensors to stressing rate tensors using Hooke's law and the elastic 
moduli from seismic velocity models.
2) There are also several clever pseudo-mechanical stress inversion 
codes out there. Stress inversions have some serious limitations, but 
when used properly, they can be quite useful. You may be interested in a 
recent JSG paper by Ole Kaven and Dave Pollard on mechanical stress 
inversions and a paper on the ECSZ by Betsy Madden and Dave Pollard.
Kaven, J. O., F. Maerten, and D. D. Pollard (2011), Mechanical analysis 
of fault slip data: Implications for paleostress analysis, Journal of 
Structural Geology, 33, 78-91.
Madden, E. H., and D. D. Pollard (2012), Integration of surface slip and 
aftershocks to constrain the 3D structure of faults involved in the M7.3 
Landers earthquake, southern California, Bulletin of the Seismological 
Society of America, 102(1), 321-342.

I hope this is helpful.
Cheers,
-Scott


On 4/30/2013 11:07 AM, Alessandro Verdecchia wrote:
> Dear all,
> I´m working on Coulomb stress calculations in Eastern California Shear Zone and Basin & Range. I would like to implement my calculations with Interseismic tectonic loading data but i have some doubts about the method to use.
> Right now I´m using the "backslip" method suggested by Savage (1983). Is this method reliable also for strike-slip and normal faults or there are any other i can use???
> Cheers
>
> MSc. geol. Alessandro Verdecchia
> LMU Munich
> Department of Earth and Environmental Sciences
> Geology
> Luisenstr. 37
> 80333 Munich
> Phone: +49 (0) 89 / 2180 6562
> Fax: +49 (0) 89 / 2180 6514
> Email: [log in to unmask]
>

-- 
<><><><><><><><><><><><><><><>
Scott T. Marshall
Department Of Geology
Appalachian State University
572 Rivers St.
Boone, NC 28608

http://www.appstate.edu/~marshallst/
ftp://pm.appstate.edu/pub/prog/marshallst/