Stream Length Gradient Responses to Active Structural Deformation in Northeastern Russia

Plate tectonic theory relies on the ability to divide the earth’s surface into a small number of ridged bodies; however, this ability to divide plates becomes complex in Northeastern Russia. The structural complexity of this region is largely due to the diffuse interactions among the boundaries that divide the North American plate, the Eurasian plate, and the Okhotsk Plate. In this study Stream Length Gradient indices were used as a means of observing, remotely and inexpensively, the actively deforming landscape of the region. The SLG indices were calculated from a wide range of rivers that vary both in size and morphology. Many of the rivers measured in this study cross or run along Ulakhan fault, which is thought to characterize the tectonic boundary between the Okhotsk plate and North American plate. Noticeable trends in the SLG indices occur within close proximity to active faults in northeast Russia; however, these trends are variable due to the different directions of motion such as strike-slip, transpressional, and thrust along these faults.