expected gouge depth: Based on the past gouging regime (gouge depth distribution and gouging frequency, especially), one must rely on probability analyses to estimate the likely maximum gouge depth at the planned pipeline deployment site during its full operational lifespan (e.g. 20–40 years). This type of analysis is not unusual in civil engineering – textbooks are written on this subject. But changing climate patterns are an added source of uncertainty, since it is uncertain how climate change will affect future gouging regimes. Subgouge deformation: Seabed gouging by ice is a relatively complex phenomenon, depending on a number of parameters (keel dimensions and properties, soil response, etc.). Even if the maximum gouge depth can be ascertained, it is difficult to assess the amount of soil displacement below it, a parameter considered when establishing what a safe pipeline burial depth should be. Pipeline strain: Another source of uncertainty is the amount of strain that the pipeline is likely to see at a given depth below the gouge. Environmental issues Oil and gas developments in Arctic waters must address environmental concerns through proper contingency plans. Parts of the Arctic are covered with ice most of the year. During the winter months, darkness prevails. If an oil spill occurs, it may go undetected for several months. Assuming this spill is located, clean-up procedures are likely to be impeded by ice cover. Furthermore, these are remote locations, such that logistical issues would come into play. Arctic ecosystems are sensitive – a timely response is required to mitigate the consequences of an oil spill. See also Drift ice Iceberg Offshore geotechnical engineering Submarine pipeline Pressure ridge (ice) Stamukha Strudel (ice) Bloop References Bibliography Abdalla B., Jukes P., Eltaher A., Duron B. (2008) The technical challenges of designing oil and gas pipelines in the Arctic, OCEANS 2008 IEEE Proceedings, Quebec City, Canada, pp. 1–11. Annandale G.W. (2006) Scour Technology: Mechanics and Engineering Practice, McGraw-Hill, New York, 420 p. Been K., Sancio R.B., Ahrabian D., Deltares W.V.K., Croasdale K., Palmer A. (2008) Subscour displacement in clays from physical tests, Proceedings of the 5th International Pipeline Conference (IPC), American Society of Mechanical Engineers (ASME), Calgary, Canada. Blasco S.M., Shearer J.M., Myers R. (1998) Seabed scouring by sea-ice: scouring process and impact rates: Canadian Beaufort Shelf. Proceedings of the 1st Ice Scour and Arctic Marine Pipelines Workshop, 13th International Symposium on Okhotsk Sea and Sea Ice, Mombetsu, Hokkaido, pp. 53–58.