The work is devoted to a problem of seismic activity of northern part of Sakhalin Island.The active faults were trenched and studied in detail.Its expressiveness in a relief and character of displacement of strata is discussed.We provide cogent evidences that young tectonic faults on Schmidt peninsula were formed as a result of sharp periodic motions with amplitudes up to several meters and are connected with strong earthquakes.The urgency of work is that there are works on search of hydrocarbons and The work is devoted to a problem of seismic activity of northern part of Sakhalin Island. The active faults were trenched and studied in detail. Its expressiveness in a relief and character of displacement of strata is discussed. We provide cogent evidences that young tectonic faults on Schmidt peninsula were formed as a result of sharp periodic motions with amplitudes up to several meters and are connected with strong earthquakes. Urgency of work is that there are there works on search of hydrocarbons and