Морфогенетическая дифференциация берегов контактных зон Северной Пацифики

The results of the analysis of geospatial and geological-geomorphological information on the shores of the contact zones of the North Pacific are presented. An analysis of the maps of the morphogenetic types of coasts of the North Pacific revealed the specifics of the coastal morpholithogenesis of the seas of subarctic and moderate zones. It has been established that for the seas of the North Pacific, a two-modal distribution of the length of coasts of various types is characteristic. The first maximum relates to abrasion-denudation rocky shores, with a significant contribution to the destruction of physical weathering. The second peak is formed by abrasive-accumulative shores. A similar distribution of coast types along with structural and geological features of the coastal structure is probably associated with various stages of coastal maturity under conditions of intense denudation destruction of the coasts of the seas, characterized by a prolonged “open sea” period at negative air temperatures. The morphoclimatic position (geospatial parameters and the related differences in morpholithodynamic parameters) of Sakhalin Island and the island arc systems of the North Pacific allowed us to consider them as contact zones of different types of seas, as well as seas and oceans. The morpholithodynamic characteristics of the shores of contact zones along with the features of hydrodynamics and the thermal regime of the shared water areas also determine the morphoclimatic parameters of the contact zone itself. The Sakhalin shores of the moderately cold northern part of the Sea of Japan and the Subarctic Sea of Okhotsk are 30-140 km apart, while the oceanic and marine shores of large islands in island-arc systems separate the first kilometers. Thus, the windwave fields and their interaction with swell waves in the contact zones are very complex. The temperature regime of the coasts also largely depends on the geospatial parameters of the contact zones. Based on the map of morphogenetic types of coasts, the distribution features of coastal types from the sea and ocean side of island-arc systems are digitized and considered. Cartometric and morphometric studies in conjunction with the data of geological and geomorphological analysis revealed the peculiarities of development and modern dynamics of the sea and ocean coasts of island-arc systems. It is assumed that the longitudinal asymmetry of the low isthmus between the ocean and sea shores is due to tsunamigenic proc