Article,
Crustal structure deduced from receiver functions via single-scattering migration
Geophysical Journal International, 150 (2): 524--541 (August 2002)
DOI: 10.1046/j.1365-246X.2002.01723.x
Abstract
An investigation of the teleseismic P-wave coda is performed using
the single-scattering approximation. The method allows one to image
short-wavelength scale (<=2 km) velocity and density heterogeneities
and structures that are barely detected by traveltime tomography.
Source effects are removed by using receiver functions for data interpretation,
but the amplitude (especially the sign of the signal) is synthesized.
Both broad-band seismological stations in the southwestern Alps (France)
and Campanian plain (Italy) are used for the illustration of the
proposed method. Because of the large aperture of our arrays, laterally
small-scale heterogeneities are difficult to image and we must assume
lateral continuity of the detectable structure. If so, we show that
this depth migration based on a single-scattering approach can recover
both the depth and the geometry of the main discontinuities below
the studied areas. In the southwestern Alps, we underline a complex
crustal structure and Moho dipping topography. The Moho depth increases
from 20 to 30 km between the coastline and the Mercantour range.
In the Campanian plain (surrounding Mount Vesuvius) we also find
a southeastwards-dipping Moho. Furthermore, the three main discontinuities
are imaged, showing a relatively shallow mantle-crust discontinuity
and a deeper one near the coastline.
