Tide Gauge in St. Petersburg (IMAGE) American Geophysical Union Caption Thomas Wahl, left, and Mark Luther, scientists at the College of Marine Science at the University of South Florida, at a tide gauge in St. Petersburg, Fla. Wahl and Luther are co-authors on a recently published study that found the seasonal sea level cycle along the eastern Gulf Coast fluctuated more over the past two decades than it had in previous years based on data from 13 tide gauges along the coast. Credit Thomas Wahl 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.