Michael Sigl in the Field (image) Desert Research Institute Caption DRI scientist Michael Sigl holds an ice core section that contains detailed information about the volcanic aerosol composition of Earth's atmosphere 1,700 years ago. Credit Olivia Maselli Usage Restrictions Please contact Justin Broglio prior to photo use. Additional photos are available upon request. 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.