The Influence of Cryogenic Processes on the Erosional Arctic Shoreface

Abstract Coastal dynamics and shoreface relief in ice-free seas are a function of hydrodynamic interactions between the sea and bottom sediments. In the Arctic, additional, cryogenic factors such as permafrost and the action of sea ice influence coastal processes. The goal of our paper is to assess this influence, mainly on the profile shape. Mathematical analyses of the shape of 63 shoreface profiles from the Laptev, Beaufort, and Chukchi Seas were carried out. The shapes of Arctic shoreface profiles and those of ice-free seas are compared. We found that large ice and silt content in perennially frozen sediments composing Arctic coasts favor their erosion. Sea ice plays an important role in sediment transport on the shoreface and correspondingly changes shoreface relief significantly. Some effects of ice intensify coastal erosion considerably, but others play a protective role. The overall influence of cryogenic processes on Arctic coasts composed of loose sediments is seen in that the average rate of coastal retreat is larger than in the temperate environments, even though Arctic coasts are protected by a continuous ice cover most of the year. The shape of the shoreface profile in the Arctic does not differ from that in ice-free seas, and is satisfactorily described by the Bruun/Dean equilibrium profile equation. The explanation of this fact is that all changes of the profile shape, caused by cryogenic processes, are short lived and quickly eliminated by wave action.

[1]  P. Bruun.  Coast Erosion and the Development of Beach Profiles , 1954 .

[2]  E. Bird,et al.  Coastline Changes: A Global Review , 1985 .

[3]  P. Barnes,et al.  SEA-ICE INFLUENCE ON ARCTIC COASTAL RETREAT. , 1987 .

[4]  F. E. Aré,et al.  Thermal abrasion of sea coasts (part I) , 1988 .

[5]  H. Kassens,et al.  Sea-ice processes in the Laptev Sea and their importance for sediment export , 1997 .

[6]  P. Barnes.  Marine Ice-Pushed Boulder Ridge, Beaufort Sea, Alaska , 1982 .

[7]  D. Inman,et al.  Shorerise and bar‐berm profiles on ocean beaches , 1993 .

[8]  Orrin H. Pilkey,et al.  The Use of Mathematical Models to Predict Beach Behavior for U.S. Coastal Engineering: A Critical Review , 2000 .

[9]  J. R. Payne,et al.  Interaction of rising frazil with suspended particles: tank experiments with applications to nature , 1993 .

[10]  César Vidal,et al.  Relationship between Beach Morphodynamics and Equilibrium Profiles , 2001 .

[11]  R. Dubois.  An Inverse Relationship Between the A and m Coefficients in the Bruun/Dean Equilibrium Profile Equation , 1999 .

[12]  P. Barnes,et al.  Arctic continental shelf morphology related to sea-ice zonation, Beaufort Sea, Alaska , 1978 .

[13]  Andrew D. Short,et al.  Handbook of beach and shoreface morphodynamics , 1999 .

[14]  K. Bodge.  Representing Equilibrium Beach Profiles with an Exponential Expression , 1992 .

[15]  P. Lee,et al.  The submarine equilibrium profile: a physical model , 1994 .

[16]  J. Harper.  Morphology of the Canadian Beaufort Sea coast , 1990 .

[17]  M. Grigoriev,et al.  Comparative shoreface evolution along the Laptev Sea coast , 2002 .

[18]  P. Barnes,et al.  Sea ice sediment entrainment and rafting in the Arctic , 1989 .

[19]  J. Harper,et al.  A Review of Beach Nourishment From Ice Transport of Shoreface Materials, Beaufort Sea, Alaska , 1990 .

[20]  Richard A. Davis,et al.  A Beach Profile Model for a Barred Coast – Case Study from Sand Key, West-Central Florida , 1998 .

[21]  E. Reimnitz.  Dinkum Sands—A Recently Foundered Arctic Island , 2005 .

[22]  P. Barnes,et al.  Correlation of nearshore ice movement with seabed ice gouges near Barrow, Alaska , 1991 .

[23]  P. Barnes,et al.  Bulldozing and resuspension of shallow-shelf sediment by ice keels: Implications for Arctic sediment transport trajectories , 1990 .

[24]  Arnaud Héquette,et al.  Coastal retreat and shoreface profile variations in the Canadian Beaufort Sea , 1990 .

[25]  E. Reimnitz,et al.  Flume studies and field observations of the interaction of frazil ice and anchor ice with sediments , 1986 .

[26]  V. Rachold.  Expeditions in Siberia in 1999 , 2000 .

[27]  P. Komar,et al.  The Analysis of Exponential Beach Profiles , 1994 .

[28]  E. Reimnitz,et al.  Dynamic ice-wallow relief of northern Alaska's nearshore , 1982 .

[29]  J. Boon,et al.  CARIBBEAN BEACH-FACE SLOPES AND BEACH EQUILIBRIUM PROFILES , 1988 .

[30]  H. Reineck,et al.  Depositional sedimentary environments , 1973 .

[31]  M. Grigoriev,et al.  Russian-German Cooperation System Laptev Sea 2000: The Expedition LENA 2000 , 2001 .

[32]  S. M. Graves,et al.  Beaufort Sea coastal erosion, sediment flux, shoreline evolution, and the erosional shelf profile , 1988 .

[33]  P. Barnes,et al.  ICE GOUGING CHARACTERISTICS AND PROCESSES , 1984 .

[34]  D. Dethleff.  Entrainment and export of Laptev Sea ice sediments, Siberian Arctic , 2005 .

[35]  W. Briggs,et al.  Suspension freezing of bottom sediment and biota in the Northwest Passage and implications for Arctic Ocean sedimentation , 1992 .