Fault Structure from Space

The geometry of fault systems both at the surface and at depth is one of the primary factors controlling the size of potential earthquakes on Earth. Big earthquakes rupture big faults or a multitude of smaller faults. Therefore, knowing the structure of faults at depth is fundamental basic knowledge required for accurate seismic hazard assessment. We describe in this chapter how space-based geodesy can unravel the geometry of faults and fault systems at depth. We first discuss the methods used to map active and inactive faults using their signature in the topography. We then review the influence of faults on surface deformation that can be measured with precision using satellite-based geodetic techniques.