Geomorphology of Viking and medieval harbours in the North Atlantic
The aim of this thesis is to understand the role of geomorphological change in the abandonment of Norse harbours in the North Atlantic. Nodes of maritime activities that were established by Norse settlers during the Scandinavian Viking Age often developed into important towns and cities. Some of these, however, disappeared for unknown reasons. Norse harbours in the North Atlantic varied in scale. They ranged from small landing beaches used by small boats for local use through to much larger anchorages handling considerable trade and being important nodes on the transatlantic trading network. Changes in coastal geomorphology necessitated a response from seafarers. In this thesis, a conceptual framework for the formation, recovery and stability of headland-dominated sandy beaches in high-energy environments is established, based on empirical observation and on the use of the MIKE21 numerical sediment transport model. Under persistent calm climatic conditions, nearshore seabed gradient is a weak control on beach formation and persistence in embayments. However, under persistent stormy conditions, nearshore sea bed gradient becomes the prominent control. Embayments with nearshore gradients of > 0.025 m/m inhibit
Preston, John Ian
coastal ; archaeology ; Norse ; medieval ; sediment transport ; sea level change ; adaptation ; Shetland ; Iceland ; Greenland
Geomorphology of Viking and medieval harbours in the North Atlantic. The aim of this thesis is to understand the role of geomorphological change in the abandonment of Norse harbours in the North Atlantic. Nodes of maritime activities that were established by Norse settlers during the Scandinavian Viking Age often developed into important towns and cities. Some of these, however, disappeared for unknown reasons. Norse harbours in the North Atlantic varied in scale. They ranged from small landing beaches used by small boats for local use through to much larger anchorages handling considerable trade and being important nodes on the transatlantic trading network. Changes in coastal geomorphology necessitated a response from seafarers. In this thesis, a conceptual framework for the formation, recovery and stability of headland-dominated sandy beaches in high-energy environments is established, based on empirical observation and on the use of the MIKE21 numerical sediment transport model. Under persistent calm climatic conditions, nearshore seabed gradient is a weak control on beach formation and persistence in embayments. However, under persistent stormy conditions, nearshore sea bed gradient becomes the prominent control. Embayments with nearshore gradients of > 0.025 m/m inhibit
geomorphology viking medieval harbour north_atlantic aim role geomorphological change abandonment norse harbour north_atlantic maritime_activity establish norse settler scandinavian viking_age often develop important town_city however disappear unknown reason norse harbour north_atlantic vary scale range small landing use small boat local use much_large handle considerable trade important node transatlantic trading network changes coastal geomorphology necessitate response seafarer conceptual_framework formation recovery stability dominated high energy environment establish base empirical observation use numerical sediment transport model persistent climatic condition gradient weak control formation persistence however persistent condition sea bed gradient becomes prominent control gradient inhibit