Formation and dynamics of an ice bustle at the Nanisivik Wharf

• Main Authors: Brown, Jeffrey, Poirier, Louis, Frederking, R. M. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: [The Conference] 2019
• Subjects: ice bustle; active zone; tidal jacking; Nanisivik; Arctic; Sea ice
• Online Access: https://nrc-publications.canada.ca/eng/view/ft/?id=ebcd5e60-8ddf-4b3d-a096-fe13068a106a; https://nrc-publications.canada.ca/eng/view/object/?id=ebcd5e60-8ddf-4b3d-a096-fe13068a106a; https://nrc-publications.canada.ca/fra/voir/objet/?id=ebcd5e60-8ddf-4b3d-a096-fe13068a106a

In the summer of 2015, the Department of National Defense’s began construction of a new deep water refueling station in Nanisivik In October of 2017, two load panels were installed on the outward face of one of three cylindrical cells making up the wharf. In June of 2018, a field team performed a short measurement program to validate the pressure panels and data logger, extract data, and collect measurements of the ice developed during the previous winter. A region of very thick ice first year sea ice in an ‘active zone’ develops around the wharf every winter. The thickness of the ice bustle and surrounding level ice was measured manually via ice auguring and an elevation survey work at the time of the June 2018 field visit. The ice feature was found to be roughly 4-5m thick on average, and the parent level ice was recorded in the range of 1.6-1.9m. The motions of the active zone were monitored via a 6 degree of freedom position tracking system throughout a full tide cycle to identify early melt-season dynamics of the ice feature. Motions of the ice in the active zone are compared with tide information demonstrating a strong dependence. The active zone ice feature forms initially from an ice bustle, ad-frozen to the wharf. The life cycle of the ice bustle and a summary of the various dynamics observed both through the measurement program and the loading records are discussed, with particular emphasis on the transition from an ad-frozen ice feature, affixed to the wharf, to a free floating bustle. A region of hard ice appeared to have formed on the steel sheet piles encasing the wharf during the spring. The impact on pressures exerted on the wharf is presented and discussed. Peer reviewed: Yes NRC publication: Yes