Pillow Basalts (IMAGE) Columbia Climate School Caption Magma from undersea eruptions congealed into forms known as pillow basalts on the Juan De Fuca Ridge, off the US Pacific Northwest. A new study shows such eruptions wax and wane on regular schedules. Credit Deborah Kelley/University of Washington 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.