Did the Vikings Trigger Dune Belt Formation in Saaremaa (Estonia)?

This study delves into the intricate evolution of the Järve coast in Saaremaa over thousands of years, employing a comprehensive, interdisciplinary approach to investigate the complex interplay between climatic shifts, geological factors, and potential anthropogenic influences on dune formation. The study prompts a crucial question: could local dune formation have been influenced or triggered by the activities of human settlers, the Vikings, the Crusaders and eventually Hanseatic League trading.

The study uses a multi-disciplinary approach, combining OSL and C14 analyses, cartographic and photographic materials, LiDAR-based relief analysis and GPR studies.

Over the past 7000 years, sea levels have been dropping due to postglacial uplift. About 4-3.5 thousand years ago, the area rose from the sea due to the uplift rate of 2.3 mm/year, coinciding with a warmer climate. From 3.5-2.5 thousand years ago, sandy spits and barrier islands were formed, which were exposed to a wide sector from SW to SE. Continuous land uplift gradually connected the Järve area with the mainland of Saaremaa, impacting wave patterns and hindering ridge formation. The Järve beach, now exposed only to S and SE, faced climate cooling during the Little Ice Age (AD 1100-1800), resulting in the formation of foredune-ridge and dune complexes that partly buried former spits and ridges. Saaremaa has been, and still is, rich in forests. However, recent analysis of old documents, maps, and aerial photographs reveals extensive deforestation in the area, which probably began during the time of the Vikings. Deforestation escalated rapidly due to an increase in marine transport, as confirmed by the fact that in 1297, coastal forest cutting was prohibited by law in the Tallinn region because sailors struggled to recognise the islands. The recent discovery of Viking shipwrecks near the study area at Salme also indicates substantial human activity over an extended period, which may have triggered dune development. During the same period, dune development has been detected in several locations along the Estonian coasts, leading us to question how much human activities have contributed to this phenomenon.

This study opens ways for further exploration into the interactions between human endeavours and natural forces, shedding light on the intricate dynamics shaping coastal landscapes. The findings not only contribute to our understanding of the Järve coast's evolution but also prompt broader considerations regarding the interconnectedness of anthropogenic activities and climatic factors in shaping coastal environments.