The aberrations are now generally thought to have occurred because of the April 5–15, 1815, Mount Tambora volcanic eruption on the island of Sumbawa, Indonesia. The eruption had a volcanic explosivity index (VEI) ranking of 7, a colossal event that ejected at least of material. It was the world's largest volcanic eruption during historic times, comparable to the Minoan eruption in the 2nd millennium BC, the Hatepe eruption of Lake Taupo at around 180 AD, the eruption of Paektu Mountain in 946 AD, and the 1257 eruption of Mount Samalas.