P. Schmoldt, PhD - MTNet - DIAS

7.3. Tajo Basin and central Spain
Fig. 7.18.: Depth of the Moho beneath the Iberian Peninsula and surrounding regions. Gridded data from seismic sounding results
by Díaz and Gallart [2009] with dots denoting the location of MT recordings carried out during the PICASSO Phase I fieldwork
campaign. Location of refraction and reflection profiles used by the authors to derive the Moho depth are given in Figure 7.19.
and crustal layer thicknesses are summarised in Table 7.2. Some authors propose an additional
low velocity layer (Vp = 5.60 km/s, Vs = 3.18 km/s) at the bottom of the upper crust
[Banda et al., 1981]. However, this has not been confirmed by recent high-resolution
experiments [Palomeras et al., 2009].
Seismic refraction
Results of seismic refraction experiments are in agreement with findings by seismic reflection
studies, indicating a three-layer crust with thicknesses of around 14 km (upper crust),
9 km (middle crust), and 8 km (lower crust); however, details about the layer properties
vary slightly between different authors. Beneath the central Iberian region, the Moho occurs
at an average depth of 31 km with no significant lateral variation except under the
SCS where the crust exhibits an increased thickness of up to 34 km [Banda et al., 1981;
Surinach and Vegas, 1998; ILIHA DSS Group, 1993; Gallart et al., 1995; Pulgar et al.,
1996].
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