Rutgers volcano evolution study (IMAGE) Rutgers University Caption The Rutgers-led researchers examined explosive ash deposits that are tens of meters thick about 35 km north of the Toba caldera in Indonesia. Credit Steve Self, UC Berkeley Usage Restrictions Credit Steve Self, UC Berkeley 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.