Characteristic slip for five great earthquakes along the Fuyun fault in China
Date of Issue2011
Earth Observatory of Singapore
The seismic hazard associated with an individual fault can be assessed from the distributions of slip and recurrence times of earthquakes. However, seismic cycle models1 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 Ms 7.9 11 August 1931 earthquake produced a surface rupture with a length of 160 km, dispersed over three different fault segments. The 290 measured stream channel and terrace offsets record an average slip of 6.3 m. 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.
© 2011 Macmillan Publishers Limited. This is the author created version of a work that has been peer reviewed and accepted for publication in Nature Geoscience, published by Nature Publishing Group on behalf of Macmillan Publishers Limited. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [dx.doi.org/10.1038/ngeo1158].