In a study in Nature, a team of geologists from the GFZ German Research Centre for Geosciences, Potsdam, compared earth movements during the Chilean earthquake to a decade's worth of measurements of strain build-up, finding that the greatest slippage indeed happened on parts of the fault that had accumulated the most strain.

The earthquake occurred on a section of the Andean subduction zone that represented a 'seismic gap' in which no major earthquake had occurred since 1835, when Charles Darwin reported one that is now thought to have had a magnitude of about 8.5.

Moreno, M., Rosenau, M. & Oncken, O. 2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone. Nature 467, 198-202 (2010).