Original paper

The influence of glacier systems of polar catchments on the functioning of the coastal zone (Recherchefjorden, Svalbard)

Zagórski, Piotr; Gajek, Grzegorz; Demczuk, Piotr

Abstract

The functioning of the polar catchment is reflected in changes (geosuccession) of the structure of the natural environment (changes in the landscape). In the case of polar catchments, sediments can be transported and deposited in the coastal zone by glaciers (moraine sediments) or proglacial water in the area of outwash plains, deltaic fans or tidal flats (watt). The studies were carried out in four, partly glaciers-covered catchments of Scottbreen, Renardbreen, Cramerbreane (Chamberlindalen) and Recherchebreen, and mouthing into the Recherchefjorden (NW part of Wedel Jarlsberg Land, Svalbard). The most significant changes concerned the areas in close vicinity of the fronts of the glaciers. The direct influence of the glacier systems and proximity of the outflow of proglacial waters facilitated intensive aggradation of the coastal zones where glacial, fluvioglacial and marine processes interacted. Approximately 30 km of the coast of Recherchefjorden was under the direct influence of glacier systems. The recession of the glaciers in the 20th century led to the formation of more than 20 km of new shoreline, especially in the forefield of the Renardbreen and Recherchebreen. The sections of the coastline located in the estuary area of the Scottbreen and Chamberlindalen catchments were supplied with terrigenous sediments with various intensity throughout the whole observations period (indirect influence). Moreover, in the case of Scottbreen catchment mouths, the direct interaction of marine processes (wind waving), their configuration and magnitude are important. The aggradation of the coastal zone occurred by widening of the storm ridge that surrounded the outwash plain. There is lack of accumulation within the tidal flat and the offshore zones, with its typical abrasion platform. The different situation was observed in the mouth section of the Chamberlindalen catchment subjected to direct waving influence. The surface of the tidal flat mainly aggraded during high water. Fine-grain sediments were mostly deposited to the tidal flat. Whereas, during the ebbing tide, certain amounts of sediments are carried out of the catchment with a few tidal channels, subaqual delta cones are developed at their mouths. The delimitation of the upper border of the tide influences in the area of the contact between outwash plains and fiord waters is impossible according to the set of methods used.

Keywords

polar catchmentsglacier systemscoastal zonerecherchefjordensvalbard