Millennial to million year normal-fault interactions in the forearc of a subduction margin, Crete, Greece

摘要

Map-scale faults located close to one another (e.g., 5 km) are likely to interact. We explore the impact of fault interactions on the thousand to million-year growth patterns of the Eastern Mirabello Fault System (EMFS), an active normal fault-system in the upper-plate of the Hellenic subduction margin. Kinematic analysis of fault displacement data shows that, over the last 2 +/- 0.5 Ma and along the entire fault-system length, the EMFS accommodated displacement at near constant rates (0.5 +/- 0.15 mm/a), with large faults in the system moving faster than small faults. This hierarchy does not however persist over shorter timescales ( 16.5 +/- 0.5 ka), with displacement-rates ranging between zero and up to 5 times faster than their million-year values. Despite this short-term variability in displacement accumulation on individual faults, temporally stable rates are achieved post similar to 16.5 ka when the entire fault system is considered. Thus, increased stability of displacement accumulation on individual faults over million-year timescales is also partly matched by increasing the spatial length scales of observation on shorter timescales ( similar to 16.5 ka), suggesting that each fault is a component of a kinematically coherent system, a feature that may lead to clustered (or synchronous) rupture on multiple faults in the system.