In April of 1815, Mount Tambora, a volcano on the island of Sumbawa in present-day Indonesia (then part of the Dutch East Indies), erupted in what is now considered the most powerful volcanic eruption in recorded human history. This eruption, with a volcanic explosivity index (VEI) of 7, ejected 37–45 km3 (8.9–10.8 cubic miles) of dense-rock equivalent (DRE) material into the atmosphere, and was the most recent confirmed VEI-7 eruption. Although the Mount Tambora eruption reached a violent climax on April 10th, 1815, increased steaming and small phreatic eruptions occurred during the next 6 months to 3 years.