P. Schmoldt, PhD - MTNet - DIAS

301
G-centre profile
The profile G-centre runs parallel to the
mantle strike direction and is located on
top of the more resistive part of the mantle
(1000 Ωm) containing stations synG01 -
synG10 (see Fig. 8.4), which are decomposed
for a geoelectric strike direction
N45W. The RMS misfit of the inversion
model is very low (0.61 with a 5%
error floor for phases and 10% error floor
for apparent resistivities) and the crustal
region is adequately recovered (see Fig.
A.9); however, the mantle region is, like
for the profile 3D-crust, significantly different
from the true model (Fig. 8.3). In
particular, the SW region of the inversion
model exhibits too high electric resistivity
values. This discrepancy between inversion
and true model responses is not
reflected by the model misfit, which denoted
too low apparent resistivities for the
SW of the inversion model and too high
values for the NE. However, these misfits
for the apparent resistivity may be due to
smoothing constraints, whereas the misfits
of the impedance phase at the surface are
due to the problematic in meeting the requirements
of the highest frequencies regarding
the cell size.
Depth (km)
Profile: G-centre
TE
Log 10(periods)
Log 10(periods)
RMS
TM
SW NE
0
-2
-1
0
1
2
3
4
-2
-1
0
1
2
3
4
50
100
150
200
250
synG10
synG09
300 0 16 32 48 64 80 96 112 128 144
Apparent resistivity
synG10
synG09
synG08
synG07
synG06
synG05
synG04
synG03
synG02
synG01
synG08
synG07
synG06
Distance (km)
Misfit
(Total = 0.61)
Log 10(Wm)
Log 10(Wm)
synG05
50
synG04
synG03
Phase
synG10
synG09
synG08
synG07
synG06
synG05
synG04
synG03
synG02
synG01
synG02
synG01
(Wm)
2000
Fig. A.9.: Isotropic 2D inversion results for the ‘G-centre’ profile on top of the synthetic 3D model (see Figure 8.4
for station locations). An electric resistivity interface at crustal depth is located between stations synG05 and synG06.
Periods between 10 s and 100 s are related to the crust–mantle boundary; see Section 8.2.1 for a description of the
model. During the inversion the crust is kept fixed at an electric resistivity value of 100 Ωm. The misfit of the
uppermost region originates from the problematic of meeting the cell size requirements for the highest frequencies.
degrees
degrees
A.3. Auxiliary inversion results for the synthetic 3D subsurface model