Three major volcanic eruptions in Indonesia were the well-known Krakatoa in 1883, Mt Tambora in 1815 and of Lake Toba 74,000 years ago. They all caused darkening of the atmoshere, up to 6 years for the Lake Toba eruption and causing harvest failuress and no summer in temperate climates from the Mt Tambora eruption. From the Krakatoa erup,tion, 36,000 people died,mainly from tsunamis. It could be heard 160km away.