Dynamic beach response to changing storminess of Unst, Shetland: implications for landing places exploited by Norse communities

Abstract

We present major new findings on the stability of Norse landing places on the island of Unst, Shetland using a combination of geomorphology, OSL dating, fetch analysis and sediment transport modelling. Islanders needed reliable access to the sea, and exploited sandy beaches as safe landing places. The persistence of beaches was important for long-term continuity of settlement and could be threatened by stormy conditions. Sediment modelling undertaken on two embayments on Unst, Lunda Wick and Sandwick, reveals major differences in the ability of sandy beaches to reform in these embayments after the onset of persistent stormy conditions; sandy beaches can endure under these conditions at Sandwick, but not at Lunda Wick. OSL dating of blown sands at Lunda Wick reveals a history of sand blow events pointing to large scale depletion of beach material throughout the Little Ice Age (beginning circa 1250 CE). This correlates with known sand blows at Sandwick, but here the beach could be replenished from the nearshore environment, something that was more problematic at Lunda Wick. These findings agree with the emerging picture of increased environment pressure from blown sands on communities throughout the North Atlantic and identifies different models of related beach persistence and change. 'ayr' on sandy beaches. If no ayr or shingle beach was available, fish was either transported wet and dried elsewhere or consumed fresh (Goodlad, 1971). Small Norse boats, such as a faering (4-man boat) were fragile craft, and it was important to have the safest landing places possible, particular in the face of storms, as mentioned by Morrison (1978): ""The extent to which it was felt profitable to push this aspect of Norse design philosophy to its very limits is illustrated by the occasional structural failures that took place in exceptional sea conditions. Undecked fishing boats far out in the open Atlantic often survived only through their sheer speed in making shelter as heavy weather blew up." While these craft may well have been able to withstand rough landings on cobble and rock coasts on occasion, it would have been a more dangerous proposition than a softer landing on sandy beaches.