Maximum Link Distance between Strike-slip Faults: Observations and Constraints

Abstract

The maximum fault link distance (lateral separation) between two interacting strike-slip faults is studied in relation to fault length (combined length of the two interacting faults). Data collected for laboratory generated strike-slip faults indicate that fault linkage takes place when the lateral separation between two strike-slip faults is less than one tenth of the combined length of the two faults. Strike-slip faults developed in clay models require a smaller link distance than those developed in gouge materials. About 98% of the data collected for natural strike-slip faults and 93% of earthquake rupture data derived from KNUEPFER (1989) follow the rule. These observations support a simple scaling relationship for strike-slip faults, i.e., W 50.1 L where W is lateral link distance and L the combined fault length (AN and SAMMIS, 1996a). Two possible explanations are discussed. Assuming a fault continues to be dominantly strike-slip after various fault coalescences, the fault link distance for both compressional coalescence (leading to restraining bend) and extensional coalescence (leading to releasing bend) can be constrained within 0.134 L. Assuming fault coalescence is caused by interaction between breakdown zones at fault tips, then the scaling relationship b =0.1 l between the size of a breakdown zone, b, and the individual fault length, l (SCHOLZ et al., 1993), leads to the scaling relationship W max = 0.1 L where W max is the maximum link distance.The above observed relationship between W max and L may not hold if faults coalesce through preexisting faults, if a fault has a mixed mode other than strike-slip, or if a fault bend is caused by cross faulting rather than fault coalescence. Limited exposure of natural fault traces may also lead to errors in link distance measurements.

How does the initial configuration of oceanic ridge segments affect their interaction? Insights from analogue models

“…Accordingly to the obtained results, S has to be 1 order of magnitude smaller that the total length of the two fractures to have interaction (see discussion by Acocella [2008]). A similar ratio between OL and the total fracture length was recognized in other experimental models [ Sempere and Macdonald , 1986; An , 1997; Tentler , 2003b] and for fractures along the oceanic ridge of Iceland [ Acocella et al , 2000; Tentler and Mazzoli , 2005].…”

M ≥ 7 earthquake rupture forecast and time‐dependent probability for the sea of Marmara region, Turkey

“…Segmentation of the NNAF beneath the Marmara Sea is especially difficult because the fault traces are not directly observable [Aksu et al, 2000;Imren et al, 2001;Le Pichon et al, 2001;Armijo et al, 2002Armijo et al, , 2005Pondard et al, 2007]. These segments are bounded by geometric fault complexities and discontinuities (e.g., jogs and fault bends) that act as barriers to rupture propagation [Segall and Pollard, 1980;Barka and Kadinsky-Cade, 1988;Wesnousky, 1988;Lettis et al, 2002;An, 1997]. Where possible, the reconstruction of the fault traces and boundaries at the surface is informed by seismotectonic studies of recent earthquakes (e.g., 1999 Izmit and Düzce seismic sequence) [Gülen et al, 2002;Barka et al, 2002;Bohnhoff et al, 2006;Bulut et al, 2007;Pucci et al, 2007;Stierle et al, 2014] and historical surface ruptures [Ambraseys and Jackson, 1998].…”

Segmentation and interaction of normal faults within the Colfiorito fault system (central Italy)

“…According to , interaction between overlapping faults develops for a ratio of horizontal separation to total length lower than 15%. Similarly, an upper limit of 10% is found to control the interaction of overlapping strike-slip fault systems (An 1997).…”