During Nansen's historic voyage on the polarship Fram, which commenced in 1893, the great depth of the central basin was discovered. The black curves correspond to a window of 10 × N time steps, and the width of the windows associated with the grey curves is indicated by the corresponding grey lines in. This brittle mechanics is independently supported by a direct comparison between the strain rates measured by Oikkonen et al. In the vicinity of this critical point, the stored elastic energy is released through power-law-distributed avalanches. This is a first motivation for a better understanding of kinematical and mechanical processes of sea ice.
A healing mechanism is also introduced, which counterbalances damaging over large time scales approx. Today research at several scientific institutions there is devoted primarily to the study of the North Polar Ocean and seas. The slow healing condition is, therefore, observed. A more upstream, theoretical motivation is a better understanding of the brittle deformation of geophysical objects across a wide range of scales. Similarly, the measure of spatial localization, β 1 , is bounded between 0 a perfectly homogeneous field and 2 a point-like process , and equation 3.
The mechanics would be the same but geography helps shield the Arctic from the long range effects of these southern storm induced swells. Indeed, owing to its very strong kinematics, compared e. The violation of at least one of these two conditions precludes the convergence upon the addition of random variables, meaning that distributions remain fat-tailed whatever the scale of coarse-graining, thus invalidating homogenization at some intermediate scale. Environmental dangers from stay one of many world's superior killers. A more upstream, theoretical motivation is a better understanding brittle deformation of geophysical objects across a wide range of scales.
Indeed, owing to its very strong kinematics, compared e. Research has been conducted year-round from drifting ice islands, which are tabular fragments of glacier ice that break away from ice shelves. Combined with cascading effects, this can lead to long-ranged time correlations of the kind of equation 3. To fully calculate a two-dimensional strain-rate tensor and the associated invariants, such as shear rate, , or divergence rate, , over a given domain, at least three sea ice trajectories have to be recorded simultaneously. In this framework, the spatial exponent decreases when increasing the time scale considered to calculate the strain rate. In this last limit, the memory of elastic deformations is lost and the macroscopic behaviour becomes predictable, with a periodic re activation of a single fault pattern.
Surely the greater amount of open water, the greater potential for wave amplification? This definitively shows that, unlike for glaciers and ice sheets, ductile crystalline deformation processes are insignificant in sea ice. At much larger regional scales, one may expect some very long wavelength variability of sea ice properties, such as brine content and porosity, as the result of large-scale environmental conditions. Section 4 will discuss the implication of these scaling properties in terms of the underlying physical and mechanical processes, whereas §5 presents how they can be used to constrain the development of a new sea ice mechanical framework. This is a first motivation for a better understanding of kinematical and mechanical processes of sea ice. However, in the context of climate change, the Arctic sea ice cover has been declining significantly over the last decades, either in terms of its concentration or thickness. Indeed, owing to its very strong kinematics, compared e.
Contents: Introduction -- Sea Ice Drift -- Sea Ice Deformation -- Sea Ice Fracturing -- Conclusion and Perspectives: Sea Ice Drift, Deformation and Fracturing in a Changing Arctic. This is left for future work. Here, we review the recent advances in the understanding of drift, deformation and fracturing obtained from these data. The importance of sea ice mechanics at all scales, though in various contexts such as climate modelling, regional forecasting and offshore engineering , raises the fundamental question of the linkage of scales. The closing chapter summarises sea ice dynamics applications and the need of sea ice dynamic knowledge and gives some final remarks on the future of this branch of science. He is therefore particularly interested in scaling properties of mechanical-related variables. Indeed, the convexity of β q implies that the spatial heterogeneity of sea ice deformation increases towards small scales, in full agreement with the scale dependence of the power-law exponent κ.
These scaling properties, which are the signature of long-range elastic interactions within the cover, constrain future developments in the modeling of sea ice mechanics. Note the use of a logarithmic y-axis in the case of the damage-rate time series. Preface ix Acknowledgements I thank Howard Cattle and Neil Wells for their guidance and assistance as members of the Workshop Organizing Committee. A more upstream, theoretical motivation is a better understanding of brittle deformation of geophysical objects across a wide range of scales. Here, we review the recent advances in the understanding of sea ice drift, deformation and fracturing obtained from these data. The sea ice cover evolution and climate change are strongly coupled through the albedo positive feedback, thus possibly explaining the Arctic amplification of climate warming.
But they still remain hopeful that one day they'll be rescued. This explosion of information about sea ice has fascinated scientists for some 20 years. We focus particularly on the scaling properties in time and scale that characterize these processes, and we emphasize the analogies that can be drawn from the deformation of the Earth's crust. A new work allows bridging the gap between these large scales and fundamental ice physics and mechanics. For the seas this information must describe the air above the sea, included. These scaling properties, which are the signature of long-range elastic interactions within the cover, constrain future developments in the modeling of sea ice mechanics. This is a first motivation for a better understanding of the kinematical and mechanical processes of sea ice.
Sea ice is a major component of polar environments, especially in the Arctic where it covers the entire Arctic Ocean throughout most of the year. Although much new data have accumulated since the publication of the Marine Geology and Oceanography of the Arctic Seas volume in 1974 Yvonne Herman, ed. Here, we review the recent advances in the understanding of sea ice drift, deformation and fracturing obtained from these data. These research platforms are occupied as weather sta tions, as well as for oceanographic and geophysical studies. Thus, both sea and swell depend on the open water fetch in the Arctic, because the swell is regionally driven. The dashed-dotted lines indicate the associated power-law scaling,.