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

Abstract

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 1 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 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.

Surface Rupture and Slip Distribution of the 1940 Imperial Valley Earthquake, Imperial Fault, Southern California: Implications for Rupture Segmentation and Dynamics

“…The width of steps and jogs relative to rupture terminations and changes in displacement provide predictive information on the locations of the likely endpoints of future ruptures (Wesnousky, 2008), and the abrupt steps in the amount of displacement could provide insights into the segmentation of a fault or individual rupture (Haeussler et al, 2004;Klinger, M w 7.1 Hector Mine, M w 7.4 Izmit, M w 7.1 Duzce, and M w 7.8 Taiwan earthquakes [Chen et al, 2001;Barka et al, 2002;Treiman et al, 2002]; the 2002 M w 7.9 Denali earthquake [Haeussler et al, 2004], and the 2010 M w 7.2 MayorCucapa earthquake among them), and to date, only a few dozen earthquakes have been mapped in sufficient detail to be useful in describing the fundamental properties of the rupture (Wesnousky, 2008). Because of recent technological advancements and greater availability of archived aerial imagery, some early instrumental ruptures are being mapped, especially those in dry environments (Kurushin et al, 1997;Kondo et al, 2005;Klinger et al, 2011;Salisbury et al, 2012), long after the actual occurrence of the rupture. Recent ruptures are also now being mapped in unprecedented detail by the application of new techniques, such as interferometric synthetic aperture radar (InSAR) and light detection and ranging (LiDAR; Peltzer et al, 1999;Wright et al, 2001;Çakir et al, 2003;Oskin et al, 2012).…”

Lateral Offset Quality Rating along Low Slip Rate Faults: Application to the Alhama de Murcia Fault (SE Iberian Peninsula)

“…Single rupture events usually cannot be identified in the geomorphic record because they have been smoothed by surface processes. Although the measured offsets are in general large (tens of meters; being the accumulation of several small offsets along time), the ability to identify them decreases with the dimensions of the offset [1,3,6]. This is obvious in offset histograms which show an exponential decrease of the number of identified elements with larger offset magnitudes [3,8,19].…”

“…After that, they sum the individual weighted PDFs along a specified fault reach to obtain the Cumulative Offset Probability Density (COPD; [18]). The COPD may be used to identify the offset sequences tied to successive earthquake ruptures (e.g., [2][3][4][5]18,19]). Van der Woerd et al, [6] also obtain a COPD for longer offsets, and they compare it to climatically driven geomorphic events, as climate variations modulate surface process rates and transitions [20].…”

“…Hazard assessment depends on this information and its uncertainty. Research activity on this topic has focused on (1) slip per event along fast-moving faults (e.g., [1][2][3][4][5]); and (2) long-term slip-rates along lower slip rate faults [6][7][8][9][10][11][12][13][14]. The distinction between them largely comes from the potential for separating the contributions of individual earthquakes to the measured offset, which is higher in the case of rapid slip and recurrence rate and low surface process rates.…”

Three-Dimensional Investigation of a 5 m Deflected Swale along the San Andreas Fault in the Carrizo Plain

“…High-resolution topography from Light Detection and Ranging (LiDAR) has become an increasingly important tool for measurement of fault-related geomorphic features and analysis of fault offset patterns (e.g., Bevis et al, 2005;Arrowsmith and Zielke, 2009;Zielke et al, 2010Klinger et al, 2011;Haddad et al, 2012;Salisbury et al, 2012). Digital elevation models (DEMs) produced from LiDAR topographic data enable easier identification and reproducible measurement of such piercing lines along with decimeter and finer-accuracy georeferencing (Gold et al, 2013).…”