Researchers Place GPS Instrument (IMAGE) Purdue University Caption Purdue University graduate student Sarah D. Stamps and Tanzanian scientist Elifuraha Saria install a Global Positioning System instrument in the Natron area of Tanzania. The Ol Doinyo Lenga volcano is visible in the background. Global Positioning Systems were used by a Purdue-led team to capture the first dyking event ever recorded within the Earth's continental crust. Credit Photo courtesy of Eric Calais 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.