Paleointensity Study Earth Magnetism Lab (IMAGE) Michigan Technological University Caption Aleksey Smirnov, a geophysicist at Michigan Tech, led a study that examines systematic bias in data gleaned from some of Earth's oldest rocks. Credit Michigan Tech, Sarah Bird 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.