Drift of Sea Ice Ridges in the Pechora Sea

Abstract

The drift of sea ice ridges and hits on an offshore structure with dimensions 200 m by 200 m have been studied for the Dolginskoye oil field in the Pechora Sea. The calculations were made with the computer program ICEBERG. The mean drift speed of the ice ridges was found to be 0·21 m/s with a maximum speed of 0·89 m/s. The expected number of hits per year was calculated to be 737. It was assumed that a total number of 133000 sea ice ridges would be produced in (or have entered) the Pechora Sea per year. Under the same assumption, the expected number of ridges entering a safety zone around a platform of 1852 m by 1852 m was found to be 5649. However, due to uncertainties concerning the population of ridges, their shapes, sizes, drag coefficients and tidal action, the results should be used with care and only considered as indicative. The ridge drift pattern was predominantly to the northeast in the winter months. A structure located at Dolginskoye will most probably be exposed to sea ice ridges that are formed in the area around Khodovarihka.