Wednesday, 12 January 2005: 9:00 AM
Living with frozen coasts
Steven M Solomon, Bedford Institute of Oceanography, Dartmouth, NS, Canada
Many regions along the northern coasts of the North American and Eurasian continents are notoriously unstable. This instability is a function of the interaction between their geology and morphology and the forcing imposed by coastal oceanographic conditions including waves, storm surge and sea ice. Large segments of the Arctic coasts are composed of unlithified, frozen sand and mud with significant proportions of ground ice. While these sediments are mechanically quite strong in the frozen state, they possess little strength when thawed and are easily eroded by waves and currents. Large portions of the coasts of the Beaufort and Chukchi Seas in North America and the Laptev, East Siberian and Kara Seas in Russia are known to be eroding at high rates (up to 10s of metres per year in some locations). These rapidly changing shorelines have been home to nomadic aboriginal societies for millennia but within the past 150 year they have seen the establishment of permanent settlements and increasing rates of industrial development. Thus human response to living in this dynamic coastal environment has shifted away from one of moving or rebuilding to other forms of accommodation including the construction of “hard” forms of shore protection to prevent damage to costly infrastructure.
Increasing community and industrial use of the Arctic coastal environment has engendered the need for systematic observations to monitor anthropogenic and natural changes in coastal dynamics and to improve our understanding of high latitude coastal processes. At the present time, there are very few observational networks (besides weather forecasting) that are used to provide warnings of coastal hazards. However recent changes in sea ice dynamics and potential changes in sea level, and storm surge frequency or severity may require an increased emphasis on coastal hazard warning systems. Past methods for observing Arctic coastal change have relied heavily on conventional air photography, along with ground and hydrographic surveys. Long-term observations of coastal waves, currents and water levels have been rare and sea ice monitoring is mostly concentrated on marine navigation routes rather than coastal stability issues or coastal ice as a transportation surface (ice roads and snowmobile travel). Recent advances in satellite remote sensing, autonomous in situ observing systems (e.g. video surveillance), and new airborne technologies (e.g. LiDAR) provide the potential for new and exciting research to achieve a better understanding of coastal processes and safe Arctic coastal development.
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