JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH, cilt.1, ss.1-37, 2023 (SCI-Expanded)
Slow, aseismic slip plays a crucial role in the initiation, propagation and arrest of large21earthquakes along active faults. In addition, aseismic slip controls the budget of elas-22tic strain in the crust, hence the amount of energy available for upcoming earthquakes.23The conditions for slow slip include specific material properties of the fault zone, pore24fluid pressure and geometrical complexities of the fault plane. Fine scale descriptions of25aseismic slip at the surface and at depth are key to determine the factors controlling the26occurrence of slow, aseismic versus rapid, seismic fault slip. We focus on the spatial and27temporal distribution of aseismic slip along the North Anatolian Fault, the plate bound-28ary accommodating the 2 cm/yr of relative motion between Anatolia and Eurasia. Along29the eastern termination of the rupture trace of the 1944 M7.3 Bolu-Gerede earthquake30lies a segment that slips aseismically since at least the 1950’s. We use Sentinel 1 time31series of displacement and GNSS data to provide a spatio-temporal description of the32kinematics of fault slip. We show that aseismic slip observed at the surface is coincident33with a shallow locking depth and that slow slip events with a return period of 2.5 years34are restricted to a specific section of the fault. In the light of historical measurements,35we discuss potential rheological implications of our results and propose a simple alter-36native model to explain the local occurrence of shallow aseismic slip at this location.