Natural Resources Canada
Title
Natural Resources Canada Marine Geological Research in the Canadian Beaufort Sea
Introduction
The Earth Science Sector of the Federal Government’s Department of Natural Resources is conducting seafloor investigations of the Canadian Beaufort Sea. This marine environmental geological research is aimed at protecting the renewable resources of the Beaufort Sea. Research activities include the mapping of ice scours generated by sea-ice pressure ridge keels, determining the geological processes influencing benthic ecosystems, assessing the current status of abandoned artificial exploration drilling islands from the 1970’s and 80’s, and understanding the nature and distribution of seafloor foundation conditions. Stabile foundation conditions are required for hydrocarbon exploration and production structures including subsea pipelines and drilling platforms. Soft seafloor sediments, frozen sediments at depth and shallow gas deposits adversely affect foundation conditions. The results of this research will reduce the impact of hydrocarbon development on the marine environment and protect the renewable resources of the sea. The following figures illustrate the nature of the research activities.
Figure 1 (Gas Vents)
Multibeam sonar image of the seafloor in Kugmallit Bay in 8m water depth showing several hundred gas vents. Vents range in size from less than 1 m to more than 20m in diameter and are up to 9m deep. Methane gas escaping from below the seafloor can be observed as patches of bubbles on the sea surface.
Figure 2 (Kopanoar Pingo Like Feature)
Multibeam sonar image of the pingo-like-feature at the Kopanoar site on the Beaufort seafloor in 60m of water. The conical mound is larger than its cousins on the Tuktoyaktuk Peninsula and is of different origin. The feature is considered to be an active mud volcano. Methane gas has been observed bubbling to the sea surface from the crest.
Figure 3 (Gary Knolls)
Three-dimensional multibeam sonar view of the Beaufort seafloor in the Gary Knolls area showing a line of several dozen pingo-like-features. These mud volcanoes range from a few metres to more than 20m high and have diameters that can be 50 to 300m across.
Figure 4 (Nipterk)
Topography of the Beaufort seafloor generated by multibeam sonar showing the remains of the artificial drilling island Nipterk in 12 m of water. Since the island was abandoned in 1985, wave action has eroded the once circular structure in a southeasterly direction . Originally 3m above sea surface the top of the island is now covered with 3 m of water.
Figure 5 (Ice Scour)
Multibeam sonar image of an ice scour on the Beaufort seafloor. The keels of sea-ice pressure ridges cut through seafloor sediments to form ‘V’ shaped incisions. Most ice scours are less than 0.5m deep but extremely deep events can exceed 2m in depth.
Figure 6 (Ice Scouring)
Topography of the Beaufort seafloor generated by multibeam sonar. The seafloor is covered with the tracks of ice scours that range in age from one year to many decades. Older scours are obliterated by newer events and/or are infilled by sediment over time.
Figure 7a (Beaufort Seafloor)
Photograph of the Beaufort seafloor in areas scoured by ice keels. Note lack of benthic fauna
Photographs of the Beaufort seafloor in undisturbed areas not scoured by ice keels.
Figure 7a (2 Anemonaes and Starfish)
Figure 7a (Gorgonian Coral)
Habitat Video Clips
Beaufort Habitat Station 18 in an undisturbed area of the Ikit Trough (location map included). Video shows seafloor over undisturbed area in approximately 60m water depth.
Beaufort Station 18
Beaufort Habitat Station 18 in an undisturbed area of the Ikit Trough (location map included). Video shows seafloor over undisturbed area in approximately 60m water depth.
Beaufort Station 22
Beaufort Habitat Station 22 in an undisturbed area of the Mackenzie Trough (location map included). Video shows seafloor over an undisturbed area in approximately 135m water depth.
Beaufort Station 27
Beaufort Habitat Station 27 in a disturbed area of the Kringalik Plateau (location map included). Video shows seafloor over an area experiencing yearly ice scouring and devoid of benthic fauna in approximately 14m water depth.