Late-quaternary transgression of the White Sea as deduced from data on GIS-Based bottom relief analysis

Аннотация

We examine the use of geoinformation systems and relevant software applications in marine geomorphology in terms of the digital elevation model of the White Sea region. The geomorphological development of the contemporary shoreline is shown on the basis of comparing the parameters of adjacent surfaces. The technique is suggested for identifying relative tectonic deformations by determining the morphoblock division of the seabed surface. In this case, the boundaries of the time interval used in investigating the tectonic dislocations are specified indirectly by the scale coefficient of the initial digital model. This indirect relationship is determined on the basis of the well-known expression of a dependence of oscillations of a massive object in an elastic medium. By analyzing the structure of seabed relief, we determined areas with a high value of tectonic deformations for the period involved (Holocene) relative to the level of marine sedimentation. A neotectonic regionalization of the surface of the White Sea bed allowed us to identify, on the basis of statistical dependencies, large planate subhorizontal surfaces of the seabed. Upon comparing the graphical analytical information obtained with geomorphological characteristics of these surfaces, we determined four submarine terraces of an abrasion-accumulative origin and drew the corresponding boundaries within which the ancient White Sea existed over the course of the Holocene. By analyzing the position of the marine terraces, we identified a relative intensification of marine abrasion processes at a particular evolutionary stage of the water area. This is associated with a crucial marker event in the development of the White Sea water area, namely its connection with the Word Ocean in the early Holocene.