Examining Fossil Coral (IMAGE) Georgia Institute of Technology Caption Georgia Tech associate professor Kim Cobb holds slabs of fossil coral taken from cores drilled in the Line Islands in the mid-Pacific Ocean. Powder from the slabs is examined in the mass spectrometer, which measures the ratio of oxygen isotopes to assess the strength of ENSO during the time the corals were growing. Credit Georgia Tech Photo: Gary Meek 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.