COASTAL EROSION STUDIES FOR FACILITIES SITING

Clients: Various Members of the Petroleum Industry

The Beaufort Sea coast is subject not only to wave-induced erosion, but also to thermal erosion. Wave-induced erosion is most pronounced during westerly storms due to the rise in sea level (storm surge) that accompanies such events. The uniquely-Arctic phenomenon of thermal bluff erosion can result not only from sea water thawing the base of the bluff, but also from elevated air temperatures thawing ice lenses embedded in the bluff face. The rate of coastal retreat is governed by a combination of wave and thermal erosion at many Arctic coastal locations, with thawed sediments augmenting the beach before being carried away by waves.

Coastal Frontiers personnel have investigated coastal erosion and the potential for ice encroachment at numerous Arctic sites to determine appropriate setback distances for coastal facilities over their intended service lives. The facilities have included coastal production pads as well as shore-crossing sites for subsea pipelines. In those instances where the natural erosion rate is unacceptably high, facilities can be protected by methods that include armoring the shoreline or insulating the bluff face with granular fill material.

Survey of Eroding Bluff, Beaufort Sea

Representative Study Tasks

  • Analysis of aerial photographs at decadal intervals from the late 1940s to the present

  • Investigation of historical accounts of erosion dating back over 100 years

  • Establishment of permanent survey baselines from which annual changes in bluff and shoreline position can be measured

  • Terrestrial and nearshore bathymetric surveys to quantify profile changes and rates of coastal retreat

  • Prediction of ice encroachment based on historical data acquired in similar Arctic coastal environments