Développements méthodologiques pour la mesure et la modélisation de faibles déformations

Nous nous intéressons plus particulièrement à la mesure et la modélisation de faibles déformations, à différentes longueurs d’onde spatiale et temporelle et non linéaires dans le temps :

** ° Amélioration des traitements en séries temporelles de données GPS et InSAR par la prise en compte de facteurs limitant leur précision

 

 

 

Figure 1 : GPS time series of North components (reference ITRF2008) during the 2010 slow earthquakes in Guerero Gap (Mexico).
Extrait de walpersdorf et al 2011.

Stations slipping during the first sub-event in green, stations slipping during the second sub-event in red, and stations affected by both events in orange. Stations are ordered according to their approximate position along-strike (top to bottom from NW to SE).

 

 

 

 

Figure 2 : Example of interferogram and atmospheric correction across the Kunlun fault, China.
Extrait de Jolivet et al., Geophys. Res. Lett., 2011.

(a) Flattened unwrapped interferogram from SAR acquisitions on 10‐16‐2006 and 11‐20‐2006, in radar geometry. (b) Corresponding stratified delay map predicted by Global Atmospheric Model ERA‐Interim. Colored dots indicate ERA‐I grid points location and correspond to colored delay functions in (e). (c) Residuals after correction of Figure 1a by Figure 1b. (d) SRTM Digital elevation model. Go : City of Golmud. (e) Black dots : pixel phase values as a function of elevation. Red, green, blue lines correspond to predicted delay functions of ERA‐I grid points in red, green, blue on (b), located in the Qaidam basin (north, 2600 m to 2800 m), in the Kunlun range (center, 2800 m to 6000 m), on the Tibetan plateau (south, 4500 m to 5000 m), respectively. Continuous, dashed and dotted are for western, central and eastern point respectively. (f) Predicted delay values as a function of InSAR phase. Red dashed line indicates the unit correlation. Correlation coefficient is 0.86.

 

** ° Adaptation de codes d’inversion conjointe de données géodésiques et sismologiques pour reconstruire l’évolution spatio-temporelle des glissements lents.

 

Figure 3 : Snapshot of the propagation of the 2006 slow slip event in the guerrero gap (mexico).
Obtained by inverting cGPS time series that recorded the sufarce movement during the transient event. Each plot covers a period of 50 d. The surface projection of the fault plane is represented with the position of GPS stations (black triangles), the changes in dip (dashed lines) and the downdip limit of the seismogenic zone (thin black line). Distances are in km from Acapulco.

 

 

Figure 3 : Snapshot of the propagation of the 2006 slow slip event in the guerrero gap (mexico).
Extrait de Radiguet et al.

Obtained by inverting cGPS time series that recorded the sufarce movement during the transient event. Each plot covers a period of 50 d. The surface projection of the fault plane is represented with the position of GPS stations (black triangles), the changes in dip (dashed lines) and the downdip limit of the seismogenic zone (thin black line). Distances are in km from Acapulco.