A geophysics professor at Brown University, John Hermance knows a lot about life's most necessary substance, water. He has taught hydrology and environmental geophysics for more than three decades and directed numerous field projects in Iceland, the Azores, the Yukon, and throughout the U.S. He is author of the Mathematical Primer on Groundwater Flow, published by Prentice Hall, and more than 70 peer-reviewed publications in scientific journals. His current research interests include regional-to-continental-scale hydrology, signal processing, and the application of geophysical field methods to modeling groundwater flow and related watershed processes.