Caractérisation du comportement d’un système de failles au cours de cycles sismiques successifs

 

** ° Répartition spatio-temporelle des séismes au sein d’un système de failles : apport de l’imagerie géoradar

 

 

Fig 1 : Shaded ’DEM’ of a buried paleosurface picked in pseudo-3D GPR data, here superimposed on the LiDAR DEM of the surface.

The 1-3 m-deep paleosurface is cut by a network of abandoned stream channels, most of them invisible at the surface, and offset by the Hope Fault (New Zealand). Measuring the ’buried’ offsets provide additional information on the past fault slip history compared to those obtained at the surface (Beauprêtre et al., 2012, GJInt.)

 

 

 

 

** ° Cinématique court-terme à l’échelle de zones de failles complexes versus cinématique long-terme

 

 

 

Fig 2 : Quito active fault system in Ecuador.

The fold belt extend over 60km and lye 300m high above the Interandean Valley. 15 years of GPS monitoring ( IG-EPN, IRD and IGN Ecuador) evidences the superficial locking below Quito city. Short term locking of the QFS correspond to the geomorphic imprints of active tectonics at Quaternary time scales. (After Alvarado et al., 2013 Tectonics.)

 

 

 

 

** ° Interactions entre failles.