Friction and fault evolution are critical aspects in earthquake studies as they directly influence the nucleation, propagation, and arrest of earthquake ruptures. We present the results of a recently developed experimental approach that investigates these important aspects using a combination of rotary shear testing and X‐ray micro‐computed tomography technology. Two sets of experiments at normal stresses (σn) of 2.5 and 1.8 MPa were conducted on synthetic laboratory faults. We identified real contact areas (Ac) on the fault surfaces and estimated sizes of contact patches by means of micro‐computed tomography image analysis. The number of contact patches and their sizes showed positive correlations with σn, and contact patch size distributions followed power law relations. The total number of contact patches decreased with increasing slip distance, and large contact patches endured longer slip distance than small ones. Secondary off‐fault fractures created by interlocking and breakdown of large contact patches were closely related to the sudden drops of frictional resistance, suggesting the dominant role of surface roughness on shear behavior especially at low stress.

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Sediment samples have been collected along the sea coast of the Curonian Spit in summer season of 2011, 2014 and 2015-years. According to grain size analysis the shoreline and the berm consist of well and very well-sorted sand, medium-sized on the southern (Russian) part of the spit, medium and fine on the northern (Lithuanian) part. ‘McLaren’ method was applied to determine the long-shore sediment transport directions. Mismatch of results with those obtained by methods based on simulation of resulted wave action did not prove the hypothesis that ‘McLaren’ method was able to reveal long-term resulted sediment transport. The hypothesis that ‘McLaren’ method indicates the directions of alongshore sediment transport during the stormy conditions preceding the sampling period was not proved also. It was concluded that application of ‘McLaren’ method in respect of the Curonian Spit shore, which is a transit one without permanent sources or sinks of sediments, is not efficient. ‘McLaren’ method was applied to describe the cross-shore sediment movement. It was found that deposits from the trough (located between the bar and shoreline) are transported to the shoreline that is in a line with the known fact about cross-shore transport of bottom material during the calm weather.