Ocean Bottom Seismometer (IMAGE) University of California - Berkeley Caption An ocean bottom seismometer being retrieved after spending 10 months on the floor of the Pacific Ocean to map the mantle 100 miles underneath the Juan de Fuca plate. Credit UC Berkeley 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.