Publication Date:
2020-05-27
Description:
We propose an innovative approach to mapping CMB topography from seismic P-wave trav- eltime inversions: instead of treating mantle velocity and CMB topography as independent parameters, as has been done so far, we account for their coupling by mantle flow, as formulated by Forte & Peltier. This approach rests on the assumption that P data are sufficiently sensitive to thermal heterogeneity, and that compositional heterogeneity, albeit important in localized regions of the mantle (e.g. within the D′′ region), is not sufficiently strong to govern the pattern of mantle-wide convection and hence the CMB topography. The resulting tomographic maps of CMB topography are physically sound, and they resolve the known discrepancy between images obtained from classic tomography on the basis of core-reflected and core-refracted seismic phases. Since the coefficients of mantle velocity structure are the only free parameters of the inversion, this joint tomography–geodynamics approach reduces the number of param- eters; nevertheless the corresponding mantle models fit the seismic data as well as the purely seismic ones.
Description:
Published
Description:
730-746
Description:
1T. Geodinamica e interno della Terra
Description:
JCR Journal
Description:
restricted
Keywords:
Seismic tomography
;
04. Solid Earth::04.01. Earth Interior::04.01.03. Mantle and Core dynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
