CGRG Bibliography of Canadian Geomorphology
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Author : Blasco, S.; Bennett, R.; Kostylev, V.; Campbell, P.; Shearer, J.; and Conlan, K.
Date : 2006.
Title : Seabed topography, geological structure and evolution of the sea-ice regime on the beaufort shelf at the western entrance to the Northwest Passage: CCGS Nahidik Research.
Publication : 3rd Annual ArcticNet Scientific Meeting. December 12-15, 2006. Victoria, British Columbia.
Issue : Abstracts Volume
Page(s) : 11.
Abstract
Research activities onboard Coast Guard vessel Nahidik feed the objectives of ArcticNet Project 1.6 to ‘map the bottom topography and geological structure of the NW Passage’ and to assess ‘sea-ice dynamics and the opening of the NW Passage’. CCGS Nahidik research is geographically located on the Beaufort Shelf at the western entrance to the Northwest Passage. Cross-linked ArcticNet/GSC/- DFO/CMN seabed topography, geology and iceregime studies are specifically focused on the mitigation of geoenvironmental impediments to Beaufort Sea hydrocarbon development including ice scouring, shallow gas hazards, unstable seabed foundation conditions, disturbance of the benthic ecosystem by development and identification of ecologically and biologically significant areas within areas of proposed development. The impact rates of extreme ice scour events over a 100 year time period is required to establish subsea pipeline burial depths. The seabed is saturated with ice scours that range in age from 1 to several hundred years. Ice scour research is focused on determining the distribution of extreme scour events generated by the present day sea-ice regime. This involves the discrimination of extreme events caused by historically more severe sea-ice regimes and determining the rates of impact of extreme events caused by the present ice regime. Discriminating recent events from the entire population is achieved through repetitive seabed mapping and understanding scour degradation processes and rates. Shallow gas deposits can be hazardous to exploration drilling. Determining the regional distribution of active gas vents including pockmarks and mud volcanoes and subseabed deposits of pressurized gas is required to minimize the potential for well blowouts. Bottom founded offshore hydrocarbon exploration and production structures such as steel drilling caissons requires stabile seabed foundation conditions. Drifting sea-ice exerts significant ice loads on such structures. These structures are required to resist these ice loads by being firmly founded in stable seabed sediments. Soft marine clays and disturbance features such as slumps adversely affect structure/seabed integrity. The benthic ecosystem can also be disturbed by hydrocarbon development. However, seabed disturbance by ice scouring in water depths less than 50m may have a greater impact than hydrocarbon development structures such as platforms and pipelines. Research has been initiated into the identification and assessment of ecologically and biologically significant areas on the seabed. In future it is anticipated that expanded and new research links with ArcticNet science projects will generate the science needed for ensuring environmental protection as Arctic offshore hydrocarbon development progresses.
Bibliography of Canadian Geomorphology