Another method that has been used to establish the date of eruption is tree-ring dating. Tree-ring data has shown that a large event interfering with normal tree growth in North America occurred during 1629–1628 (±65 years) BCE. Evidence of a climatic event around 1628 BCE has been found in studies of growth depression of European oaks in Ireland and of Scotch pines in Sweden. Bristlecone pine frost rings also indicate a date of 1627 BCE, supporting the late 1600s BCE dating. McAneney and Baillie argue that there is a chronological error in the Greenland ice core dates with ice core dates being around 14 years too old in the 17th century BCE, thus implying that the eruption of Aniakchak, and not Thera, may have been the cause of the climatic upset evidenced by northern hemisphere tree-rings around 1627 BCE.