Simplified Hydrology Model (IMAGE) University of Oklahoma Caption Caption: This simplified hydrology model shows the subsurface of Oklahoma. The Arbuckle Group is the area where most wastewater is injected. This layer allows fluid to move easily to distant areas. The added water causes stress as it travels and can cause earthquakes when it encounters pre-existing faults. Credit Mewbourne College of Earth and Energy University of Oklahoma 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.