Measuring the tide mark after a storm (IMAGE) University of Groningen Caption This image shows how the tide mark on a dike is measured after a storm. Credit B. Marin-Diaz, University of Groningen Usage Restrictions Credit must be given to the creator. License CC BY 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.