Abstract
Oil spills in ice-covered waters pose unique challenges to remediation activities. In-situ burning is a potential remediation technique that has shown promising efficiency in earlier trials. An element of arctic in-situ burning is the feedback between the flame of a burn on oil-infiltrated sea ice and the melting ice beneath. A series of experiments was devised to quantify the impact of this mechanism on burn efficiency. Seven experiments were performed that started with a crude oil pool of 0.2 or 0.3 m diameter on a 1 x 1 m2 freshwater ice block. The pools were ignited and the development of the flame, ice temperatures, and ablation rates was monitored. All burns ended in a vigorous burn phase (boil-over). Burn efficiency was below 65 %. A simple pond spread model was used to derive burn rates of a spreading pond. Burn rates were mostly around 0.9 mm/min. The low burn efficiencies were found to result from significant increase of the pond area during the burn in combination with relatively thin initial oil pools. The measurements provide a starting point to address the feedback effect of pond spread and ablation on burns on an oil-infested sea ice surface layer.