Shoreface of the Arctic seas - a natural laboratory for subsea permafrost dynamics

Subsea permafrost on the Arctic shelf occupies some 13 million km(2), but is poorly understood. Mathematical modeling, based on the differential equation of heat conduction, is widely used for the compilation of predictive permafrost maps. Realistic geocryological conditions on the Arctic shelf cannot however be explained simply by heat conduction. Laboratory and field investigations show that heat convection and mass transfer play an important role in marine permafrost dynamics. Correspondingly, mathematical models are not yet developed, not only because of the complexity of the problem, but due to a limited understanding of subsea permafrost properties. Comprehensive experimental investigations of subsea permafrost are therefore required. The shoreface of erosional coasts are ideal locations for field investigations, as the distance from the retreating shore seaward represents a time scale, and degradation of the submerged permafrost may be traced from its inception.