An EDM/GPS network was set up in 1994. Over three campaigns (spanning 1994 to 1997), no significant deformation was identified on the western flank of Cumbre Vieja (the last volcanic expression of a succession of growing and overlapping volcanic centers in La Palma). However, the area was limited to a fault previously active in 1949 (Moss et al., 1999).
In 2006, a GPS network of 26 stations was installed over the entire La Palma Island and revisited in 2006, 2007 and 2008; the 1994 sites were also included in this network. Significant ground deformation at Teneguia volcano (the area of the last eruption in 1971) was measured (Prieto et al., 2009). The results indicate linear velocities of subsidence between 4 and 9 mm/year, with the greatest amount of deformation on the western flank. A thermal source is interpreted as the most probable origin for deformation. These results agreed with InSAR results (Perlock et al., 2008).
InSAR data between 1992 and 2008 indicate movement on the western flank of Cumbre Vieja. González et al. (2010) interpret the deformation as shallow slip of a near-horizontal dislocation beneath the western flank, due to creeping stress release due to gravitational loading in the most recent inter-eruptive period.
To the best of our knowledge, no geodetic results post-2008 have been published.