Heightened early medieval storminess across the Chukchi Sea, AD 400–1100: A proxy of the Late Antique Little Ice Age

Abstract

Beach ridges and spits along the north-facing coast of the Chukchi Sea record paleo-storm history during the 1st millennium AD, correlative with a widespread global cooling climate episode. Northwest Alaska is a sensitive proxy owing to its absence of tectonism, glacio-isostasy, and a low rate of eustatic sea level rise. Four locales provide a regional transect and detailed chronologies: north-facing Deering and Cape Espenberg and west-facing Kotzebue and southwest facing Point Barrow. A single storm or series of storms during AD 400–600 impacted both north and south areas, while lesser intensity storms occurred across the southern region during the 11th century AD. The first millennium AD storms were as strong as or stronger than those of the 20th century, if paleo-sea level is factored in. Storm-heightened upwelling had a salubrious effect on cultures around the Chukchi Sea, leading to a florescence of whaling and walrusing.