Characteristic slip for five great earthquakes along the Fuyun fault in China

Y. Klinger (1) , M. Etchebes (1) , P. Tapponnier , C. Narteau (1)

1 IPGP - Institut de Physique du Globe de Paris

The seismic hazard associated with an individual fault can be assessed from the distributions of slip and recurrence times of earthquakes. However, seismic cycle models that aim to predict rupture lengths and fault displacements of successive earthquakes on one fault remain poorly validated. It is therefore unknown whether individual fault segments rupture independently, producing earthquakes with a diverse range of magnitudes and recurrence times, or slip by characteristic amounts, with characteristic magnitudes. Here we use high-resolution satellite data to document the horizontal offsets of stream channels and terraces created by strike-slip motion on the Fuyun fault, Xinjiang, China, during five historical earthquakes. We find that the M_s 7.9 11 August 1931 earthquake produced a surface rupture with a length of 160km, dispersed over three different fault segments. The 290 measured stream channel and terrace offsets record an average slip of 6.3m. We use the degree of preservation of geomorphological markers to assign relative ages to individual fault offsets and identify at least four distinct older earthquakes. We find that these older earthquakes also produced fault offsets with a similar distribution to the 1931 earthquake. As the slip distributions during five successive earthquakes were so similar, we conclude that ruptures on the Fuyun fault obey a characteristic slip model.

Domains: Sciences of the Universe [physics]

Y. Klinger, M. Etchebes, P. Tapponnier, C. Narteau. Characteristic slip for five great earthquakes along the Fuyun fault in China. Nature Geoscience, 2011, 4, pp.389-392. ⟨10.1038/ngeo1158⟩. ⟨insu-03606470⟩