|
|
Earth-prints >
Affiliation >
INGV >
Papers Published / Papers in press >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/2122/2070
|
| Title: | Determining the optimal Bouguer density for a gravity data set: implications for the isostatic setting of the Mediterranean Sea |
| Authors: | Caratori Tontini, F.* Graziano, F.* Cocchi, L.* Carmisciano, C.* Stefanelli, P.* |
| Keywords: | density fractals |
| Issue Date: | 2007 |
| Publisher: | Blackwell |
| Title of journal: | Geophysical Journal International |
| Series/Report no.: | /169 (2007) |
| Abstract: | We have used free-air gravity satellite data from GEOSAT and ERS-1 missions to compile a
Bouguer gravity map of the Mediterranean Sea. The complete Bouguer correction has been
applied by using the method of Parker, that acts in the Fourier domain and permits the exact
evaluation of the gravity contribution from an highly sampled topographic model of the land.
The density used for the Bouguer reduction has been obtained from the gravity data set itself,
by using two different optimization methods that have given the same optimal result of
2400 kgm−3. We have studied the radial power spectrum of the data, choosing the optimal
Bouguer density from its slope, as the one which minimizes the fractal dimension of the resulting
gravity map. The second approach consists of studying the correlation between topography
and Bouguer anomaly by spatial cross-plots for a significant subset of the data. Both these approaches
are aimed at reducing the short-wavelength effects of topography in the gravity map,
but in the past they have been traditionally used alternatively since they gave different optimization
values, especially the second method that seems to ignore large-wavelength isostatic
effects. Actually, we have revisited both the methodologies, proposing slight modifications to
make their efforts compatible. Their coincident results confirmtheir validity of application and
give reliability to the recovered value of the Bouguer optimal density. Moreover, modifying the
second approach allows us to compile a sort of normalized correlation map, which we propose
in this paper, defining the 2-D isostatic setting of the investigated region without introducing
any further lithospheric model. The final result is a revised Bouguer map compiled using a
grid with a resolution of 2 min, that is useful for large-scale geological studies and gives important
information about the compensation mechanism of the Mediterranean Sea: in a direct
way we have found that the overall region seems to be in a complete isostatic equilibrium
apart from the young basins of Tyrrhenian Sea and Aegean Sea, confirming previous similar
results. |
| URI: | http://hdl.handle.net/2122/2070 |
| DOI: | 10.1111/j.1365-246X.2007.03340.x |
| Appears in Collections: | Papers Published / Papers in press 04.03.03. Gravity and isostasy
|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
|