GPS station in the Eastern Sierra Nevada (IMAGE) University of Texas at Austin Caption A GPS station atop the Sierra Nevada mountains. Researchers at The University of Texas at Austin used GPS networks to image the planet’s interior. Credit UNAVCO/National Science Foundation Usage Restrictions Credit must be given to the creator. Adaptations must be shared under the same terms. License CC BY-SA 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.