ABSTRACT
The article describes a complex approach to the study of ice ridges and stamukhi, including methods: water thermal drilling, total station and sonar surveys, video filming with help of a submersible vehicle, determining the physical and strength properties of ice. The result of this study is the assessment of the morphometric, strength and age-related properties of the ice feature, as shown by the example of the old composite ice ridge of the East Siberian Sea.
Ice ridges and stamukhi are large ice features that have a significant mass and are typical of freezing water areas. To determine the possible ice load on marine objects, it is necessary to know the morphometric and physical strength characteristics of ice features. To obtain all necessary characteristics, it is advisable to use several methods.
During the joint expeditions of the AARI and Rosneft Oil Company in 2013-2017, more than 150 ice features were investigated in the seas of the Russian Arctic. In most cases, a set of methods was used, including determination of the morphometry and internal structure of ice features using water thermal drilling, total station survey of the surface, sonar and video of the underwater surface of the ice feature, determination of the local ice strength using a borehole jack, taking ice samples to determine the physical (temperature, salinity, density) and strength (compressive and bending strength) properties of ice.
The purpose of this article is to demonstrate a comprehensive study of the morphometry and physical-strength properties of ice feature using the example of an old composite ice ridge, to discuss the results, as well as a comparative analysis of the morphometric characteristics of a composite ice ridge with similar parameters of first-year ridges studied during the same period in the same region.
On May 9, 2015, as a result of the landing from the Atomic icebreaker "Yamal" on drifting ice north of Bennett Island in the East Siberian Sea, an investigation of the old ice ridge was carried out using various methods. The ice station at which the old ice ridge was studied was located on the ice breccia of first- and second-year ice at a point with coordinates 77°05,1′ N and 149°12,6′ E. During the work, the following hydrometeorological conditions were observed: air temperature −12.1 °C; northeast wind 7 m/s, clear; seawater temperature under ice −1.48 °C; salinity of seawater 26.83 ‰; the depth of the sea is 43 m. The old ice ridge was a complex ice feature, in which two crests could be distinguished (see Fig. 1).
