Lithic technology before and after the Storegga tsunami (8200 cal BP): Dissolving large-scale regional trends to identify social impact of crisis in western Norway

Around 8200 years ago, the Storegga tsunami hit the west coast of South Norway. The physical extent of the tsunami has been well documented but the consequences of the event for contemporary societies have received little attention beyond broad generalizations and, more recently, demographic studies based on statistical modeling of radiocarbon dates. In this paper, we explore whether the different physical impacts of the Storrega tsunami could have initiated observed regional developments in lithic technology. We have analyzed lithic assemblages from 30 carefully selected Middle and Late Mesolithic sites (dated between c. 7500 and 5000 cal BC) spread across six designated “focus areas” along the coast of western South-Norway. We identified five blade production concepts in use during the Late Mesolithic and highlight potentially significant differences in their spatial and temporal distribution. Although neither the tsunami nor the environmental stresses experienced by Mesolithic communities appear to have prompted large breaks in traditional practices, we suggest that the event marks a point in time from where specific differences and modifications in lithic technology start developing at a local scale. We argue that sudden, yet transitory events such as the Storegga tsunami, may rupture the historical contingency of social networks and communication lines resulting in changing social contexts influencing material change.