Research
Dr Georges Pichot
Management Unit of the Mathematical Model of the North Sea
(MUMM)
Belgian Royal Institute of Natural Sciences
Gulledelle, 100
B-1200 BRUSSELS
Phone: +32 (0)2 773 21 22
Fax: +32 (0)2 773 69 72
E-mail: G.Pichot@mumm.ac.be
A model of oil behaviour in ice-infested waters has been developed, which describes the interactions between oil and ice coupled with a sea ice formation model. The main features of oil spreading and dynamics in an ice pack are taken into account in the model which has been tested in three different situations: at short term in cold waters and in the presence of ice, and at long term.
On the basis of existing literature and observations, interactions between ice and oil have been identified and introduced in a sea ice formation model to study the possible fate of oil pollution in the Weddell Sea. The experiment shows that the mean drift of oil follows the Weddell Gyre, which takes the remaining contamination toward the circumpolar current. It appears clearly that the presence of ice pack completely modifies the evolution of an oil slick which acts as a moving boundary, controlling the spreading and the drift of an oil slick.
One of the key results of the long term scenario is to show that almost 20% of the initially released oil cause later and further away a second pollution event. Since the evolution of the oil slick strongly depends on the way that oil and ice interact and since each accident has thus its own features, it is evident that, in other circumstances, a greater percentage or even all the oil could be blocked under ice provoking this kind of delayed pollution, which cannot be considered any more as "accidental".
If one has to admit that logistical difficulties inherent to the Antarctic area hamper appropriate reactions in the very beginning of an accident, that is no more the case when one has in advance clear information on the time of an oil spill, its position, and the involved quantities, which is the case for this second spill.
Without prejudice to complementary efforts concerning its validation, a major interest of the present model is to provide a tool able to deliver such information to authorities and intervention teams who would thus not be caught off their guard.
More about this research-work at MUMM-ANTAR.