Eastward Bound (image) The Earth Institute at Columbia University Share Print E-Mail Caption The 100th meridian west (solid line) has long been considered the divide between the relatively moist eastern United States, and the more arid West. Climate change may already have started shifting the divide eastward (dotted line). Credit Modified from Seager et al. Earth Interactions, 2018 Usage Restrictions Credit must be given. Share Print E-Mail 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.