Ashley Streig, University of Oregon (IMAGE) University of Oregon Caption University of Oregon doctoral student Ashley Streig shows a tree stump on which tree-ring dating indicates the tree was cut prior to the earthquake of 1838 on the San Andreas Fault in the Santa Cruz Mountains. Credit University of Oregon 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.