In order to perform a site selection for paleoseismological studies the methodological approach carried out in the Eastern Pyrenees area was founded in different techniques:

- Neotectonics : In order to stablish the precise location of the possible ruptures at surface affecting to quaternary sediments, a complete inventory of recent deformations have been performed in the region. This task allow us to concentrate our paleoseismological work in particular areas.

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Figure 8 : Little recorded deformations of dextral strike-slip faults of the Estephanorhinus etruscus
(Galobart, 1996; 1.6 MY BP). This vestige constitutes an exceptional neotectonic evidence
in the Tortellà-Besalú neogene basin (see boots at the right top for the scale).

- Imagery analysis : The use of the remote sensing to find the expression of the big lineaments has been performed. Different sensors at different scales and scenes with major contrast of seasons have been analysed, from 1:250.000 until 1:100.000, Radar, Landsat and Spot images. Classical aerial photography at different scales, from 1:33.000 at 1:5.000, also has been used for a more accurate situation of the deduced lineaments from imagery technique.

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.. Figure 9 : Overview the Montesquieu and Le Boulou faults in the Southern limit of
the Roussillon neogene basin on a Spot image.

- Geomorphologic analysis : The use of the classical aerial photography have permitted to locate more precisely the geomorphologic expression of the recent activity of the faults. This activity is point out in the active mountainous fronts with the presence of the Quaternary alluvial fans, faceted spurs, tectonic control of the fluvial network, basin shapes, spacing between drainage basins, etc.

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Figure 10 : Geomorphologic map of the Amer-Brugent
system fault (Ferrer et al., 1999). The grid is 1Km spacing.

- Digital elevation model : Digital elevation model of the eastern Pyrenees area has been extracted in two different gridding resolution, from the Institut Cartogràfic de Catalunya (Spanish side) and from the Institut Géographique National (French side). Some processing techniques of the shaded relief, the slope derivation, the slope orientation, etc. have been performed in order to identify topographic anomalies. Moreover, new surveys of the topographic restoration with a major gridding resolution will allow us a more precise localisation of the anomalies.

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.Figure 11 : French DEM of the Alberes montainous front with the representation of the main tectonic
features (Montesquieu and Le Bolou faults) and Tech river valley (Maureillas fault).

- Geophysical prospecting : The use of geophysical techniques allow us to identify with an accurate localisation the possible fault trace in the upper Quaternary levels below the ground surface. These different techniques include ground-penetrating radar, geo-electric measurements, geo-electric tomography profiles and seismic refraction campaigns. In each case, the used technique is different due to the different site conditions, type of materials, resistivity contrast values, watertable, possible interference with the anthropic modifications, etc.

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Figure 12 : Seismic survey in the Bas valley on the Joanetes quaternary alluvial fan in the Amer-Brugent
system fault. We can see the Bison recorder of 48 channels, Rotalong selector, bateries and cables.

- Differential GPS measurements and levelling paths : ICC has an equipment of geodetic tools that permit to quantify the geomorphic expression of faults. The differential GPS technique measures with an accuracy better than a half meter. With this measurement we can obtain a more precise geomorphologic anomaly localisation and a well-resolved topographic profiles.

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Figure 13 : Base station on the Joanetes alluvial fan during a differential GPS campaign. You can see the Puigsacalm mountain (1515m of high) and the eroded anticline W-E of Joanetes.

- Speleothems in caves : In order to find evidences of large seismic events, the exploration, the discovering and the analysis of the growth anomalies of speleothems in karstic caves located in the area of greatest damage of the 1428 Catalan earthquake, could give us precious informations on recurrence times of large paleo-earthquakes. C14 dating of carbonate laminations taken on particular concretions will confirm the evidence of these major events and will be a useful tool to date ancient earthquakes.

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Figure 14 : Examples of the anomalies in the growth of the speleothems in the
Rialb cave situated in the epicentral area of 1428 Catalan earthquake.