Tambora Caldera Today (IMAGE) University of California - Berkeley Caption The summit caldera of Tambora, which is about 6 kilometers wide and 7 kilometers long and more than 1 kilometer deep, was created by the 1815 eruption. Gray eruptive products form the top of the caldera wall (foreground) and appear to be 200-year-old pyroclastic flow or late surge deposits. On the floor of the caldera is an ephemeral lake (center) and a small cone from a post-1815 eruption (lower right of lake). Credit Katie Preece photo Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.