The paper reviews the history of research into the behavior spills in ice covered waters and documents our current state of knowledge, drawing on the findings from a number of milestone field experiments conducted over the past 40 years. In particular the paper focuses on the unique aspects of spill behavior in different ice regimes that can both hinder and benefit spill response, depending on the timing and type of release. With increasing interest in exploiting Arctic oil resources, the knowledge base summarized in this paper can be used to identify priority topics for future research and development.
There is an extensive background of research into all aspects of Arctic spill response and our level of understanding is extremely good in many areas, such as understanding how close pack ice contains the oil from spreading, how oil trapped in the ice through the winter is maintained in a fresh state, and how trapped oil is exposed on the ice surface in the spring. Key observations from large-scale field experiments are that the natural containment, reduced wave action and slower weathering in the presence of significant ice cover, can greatly extend the windows of opportunity and effectiveness for response operations such as burning and dispersant application. These benefits are not experienced with traditional response options relying on boom and skimmer systems where ice interference severely reduces the recovery effectiveness.
Future advances in our ability to respond to spills in ice will require a new approach to permitting experimental spills. The record shows that it is entirely possible to plan and execute experiments safely with no harm to the environment. Continued regulatory intransigence could jeopardize industry's ability to develop credible and effective contingency plans to permit future Arctic exploration and development activities.
The issue of oil spill clean-up in ice continues to grow in importance as exploration drilling outside of the traditional summer open water period becomes more and more technically feasible with advanced marine technology supported by active ice management and capable vessels. Exploiting this capability requires the operator to prepare a credible oil discharge contingency plan that covers the possibility (regardless of how remote) that a late-season blowout could lead to large volumes of oil trapped under moving ice and potentially drifting unrecovered through the winter. This is a fundamental issue that is now being considered through governmental hearings and commissions in the US and Canada prompted by the 2010 Deepwater Horizon incident. In order to understand the challenges of dealing with this scenario, it is important understand the different processes governing the likely behavior of oil in a variety of ice conditions and to assess our current state of knowledge in this area.