Publications des scientifiques de l'IRD

Baize S., Audin Laurence, Alvarado A., Jomard H., Champenois J. (2016). Earthquake fault segmentation in the central Andes, Ecuador. In : 7th International INQUA meeting on Paleoseismology, Active Tectonics and Archeoseismology (PATA). s.l. : INQUA, 4 p. PATA : International INQUA Meeting on Paleoseismology, Active Tectonics and Archeoseismology, 7.

Titre du document
Earthquake fault segmentation in the central Andes, Ecuador
Année de publication
2016
Type de document
Colloque
Auteurs
Baize S., Audin Laurence, Alvarado A., Jomard H., Champenois J.
In
7th International INQUA meeting on Paleoseismology, Active Tectonics and Archeoseismology (PATA)
Source
s.l. : INQUA, 2016, 4 p.
Colloque
PATA : International INQUA Meeting on Paleoseismology, Active Tectonics and Archeoseismology, 7.
Field investigations have been carried out along the fault system that accommodates the relative motion between the North Andean Sliver and the South American Plate in Ecuador. The project aims at mapping the segmentation of this major active fault system. A series of fault strands newly mapped in direct continuation to the Pallatanga Fault (PF) to the north allow the definition of a large structure capable of triggering large events. This is confirmed by the presence of historical well-preserved scarps and decametric offsets (probably due to the 1797 M7.5 Riobamba event) disrupting the Igualata volcano. We could not find evidence for any structural continuity between the PF and the fault mapped in the Huisla volcano to the NE. We suggest that a 5-10 km wide step over separates the two segments and probably blocked the 1797 rupture. A recent surface rupture has also been recently discovered during the M5 Pisayambo quake along the Cosanga Fault (CF) system, with uncommon surface rupture length and displacement. From the few unearthed evidences, we estimate at a first glance that the mean slip rate along the PF and CF is similar (≈1 mm/yr).
Plan de classement
Géologie et formations superficielles [064]
Localisation
Fonds IRD [F B010067222]
Identifiant IRD
fdi:010067222
Contact