A Geo Information System (GIS) for circum-arctic coastal dynamics

Coastal erosion forms a major source of the sediment, organic carbon and nutrient flux into the arctic basin. Recent studies indicate that sediment input resulting from the erosion of ice-rich, permafrost-dominated coasts might be equal to or greater than river input. The program Arctic Coastal Dynamics (ACD) has been developed to improve our understanding of circum-arctic coastal dynamics as a function of environmental forcing, coastal geology, geocryology and morphodynamic behavior. Under this framework a circum-arctic Geo Information System (GIS) has been developed, which is applied to display generalized information on coastal characteristics and to analyse coastal material fluxes. The coastal GIS is based on a digital elevation model, which was constructed from the International Bathymetric Chart of the Arctic Ocean, and permafrost parameters adopted from the Circumpolar Active-Layer Permafrost System. A segmentation of the Laptev Sea coastline was performed as a first step towards a GIS-based quantification of the sediment and total organic carbon (TOC) fluxes resulting from coastal erosion

Sediment and organic carbon fluxes in connection with eroding permafrost coasts of the Siberian Arctic : extended abstract

During the last decade detailed coastal studies along the Arctic Seas have been conducted within the frame of the Arctic Coastal Dynamics (ACD) Program. The results indicate that shore dynamics play an important role in the balance of sediment and organic carbon in the Arctic basin. Arctic coastal sediment flux exceeds river sediment discharge and other terrestrial sediment sources. Based on newly obtained data, this presentation evaluates average coastal erosion rates as well as sediment and organic fluxes within the Siberian Arctic coastal Zone. The Siberian Arctic sector includes four seas: the Kara, Laptev, East Sibesian and Chukchi Seas. The total length of the Siberian Arctic coastline, including the islands, is about 29,500 km. Most parts of this coast are characterized by very active coastal erosion processes. A considerable proportion of the Siberian Arctic coasts (especially for the Laptev and East Siberian Seas) consists of ice-rich permafrost deposits, which are rapidly reworked by sea erosion. It has been found that the coastal sediment flux into the seas listed above plays a dominant role in their sediment budget. Based on the amount of coastal sediment released to the sea and the average organic carbon contents of the key types of coastal deposits, the total organic carbon (TOC) supplied to the Siberian Arctic Seas (SAS) has been estimated. The assessment of these lithologic-dynamic Parameters is based On unified methods, which involve detailed coastal segmentation and GIS-analyses. The calculated values of the sediment and TOC fluxes are considerably different from previously published data. Our results suggest that both coastal sediment flux (158 million tons per year) and coastal TOC flux (4.6 million tons per year) to the SAS significantly contribute to the Arctic Ocean sediment and carbon budget. This study was supported by the INTAS (grant 01 - 2329)

Arctic Coastal Dynamics (ACD) - status report

Coastal dynamics directly reflecting the complicated land-ocean interactions play an important role in the balance of sediments, organic carbon and nutrients in the Arctic basin. Recent studies indicate that sediment input to the Arctic shelves resulting from erosion of ice-rich, permafrost-dominated coasts may be equal to or greater than input from rivers. Thus, the understanding and quantification of coastal processes is critical for interpreting the geological history of the Arctic shelves. The predictions of future behavior of these coasts in response to climatic and sea level changes is an important issue because most of the human activity that occurs at high latitudes concentrates on the Arctic coastlines. Arctic Coastal Dynamics (ACD) is a multi-disciplinary, multi-national project of the International Arctic Sciences Committee (IASC) and the International Permafrost Association (IPA). Its overall objective is to improve our understanding of circum-Arctic coastal dynamics as a function of environmental forcing, coastal geology and cryology and morphodynamic behavior. In particular, ACD aims to: establish the rates and magnitudes of erosion and accumulation of Arctic coasts; develop a network of long-term monitoring sites; identify and undertake focused research on critical processes; estimate the amount of sediments and organic carbon derived from coastal erosion; refine and apply an Arctic coastal classification (includes ground-ice, permafrost, geology etc.) in digital form (GIS format); extract and utilize existing information on relevant environmental forcing parameters (e.g. wind speed, sea level, fetch, sea ice etc.); produce a series of thematic and derived maps (e.g. coastal classification, ground-ice, sensitivity etc.); develop empirical models to assess the sensitivity of Arctic coasts to environmental variability and human impacts. At the present state, emphasis is on developing a reliable circum-Arctic estimate of sediment and organic carbon input from coastal erosion to the inner shelf, which involves classifying and segmenting the entire circum-Arctic coastline into common elements based primarily on morphology, ground-ice composition and erosion rates. During the third IASC-sponsored ACD workshop, held in Oslo (Norway) on 2-5 Dec. 2002, regional working groups continued previous efforts for their sectors and the final version of the segmentation and classification will be available at the next ACD workshop to be organized in St. Petersburg (Russia) in Nov. 2003. Additionally, representative photographs of coastal sites for each sector for inclusion in a coastal photo library available at the ACD web site were selected during the Oslo meeting. Finally, two circum-Arctic working groups focused on GIS development and extraction and presentation of environmental data, respectively