diagram of astereroid impact crater (IMAGE) University of Göttingen Caption The concentric pattern of outcropping strata at the ground surface essentially reflects, besides of sediment compaction, a long-term sagging of the crater floor. Credit Gernot Arp, University of Goettingen 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.