Publications des scientifiques de l'IRD

Bouchon M., Marsan D., Durand V., Campillo M., Perfettini Hugo, Madariaga R., Gardonio B. (2016). Potential slab deformation and plunge prior to the Tohoku, Iquique and Maule earthquakes. Nature Geoscience, 9 (5), p. 380-383 + 1 p. ISSN 1752-0894.

Titre du document
Potential slab deformation and plunge prior to the Tohoku, Iquique and Maule earthquakes
Année de publication
2016
Type de document
Article référencé dans le Web of Science WOS:000375274800016
Auteurs
Bouchon M., Marsan D., Durand V., Campillo M., Perfettini Hugo, Madariaga R., Gardonio B.
Source
Nature Geoscience, 2016, 9 (5), p. 380-383 + 1 p. ISSN 1752-0894
Megathrust earthquakes rupture hundreds of kilometres of the shallow plate interface in subduction zones, typically at depths of less than 50 km. Intense foreshock activity preceded the 2011 M-w 9 Tohoku-oki (Japan) and 2014 M-w 8.2 Iquique (Chile) megathrust earthquakes. This pre-earthquake activity was thought to be generated(1-6) by slow slip in the seismogenic zone before rupture, but where this slow slip originated and how it spread rapidly over long distances are unknown. Here we analyse seismic activity deep in the subduction zone before the Tohoku-oki and Iquique ruptures, as well as before the 2010 M-w 8.8 Maule earthquake in Chile. We find that, before each of these megathrust earthquakes, shallow seismicity occurred synchronously with bursts of seismic activity deep (similar to 100 km) in the subducting slab. The extensional mechanism of these deep shocks suggests that the slab was stretched at depth. We therefore propose that, before these megathrust quakes, the slab might have started to plunge into the mantle below part of the future rupture zone. We speculate that synchronization between deep and shallow seismicity may have marked the nucleation phase for these three giant earthquakes.
Plan de classement
Géophysique interne [066]
Description Géographique
JAPON ; CHILI
Localisation
Fonds IRD [F B010066826]
Identifiant IRD
fdi:010066826
Contact