During the millennium, there were three known volcanic eruptions which registered magnitude 5 or more on the Volcanic Explosivity Index (VEI). These were at Ulleungdo (aka Ulreung), an island east of the Korean Peninsula about 8750 BC; Grímsvötn, north east Iceland about 8230 BC; and Taupo Caldera, New Zealand about 8130 BC. The biggest eruption was at Grímsvötn, VEI 6, producing some of tephra.