Sea Ice Thickness Sonde EM-Bird (IMAGE) Helmholtz Association Caption Polar 5 towing a sonde for sea ice thickness measurements -- the so-called EM-Bird -- on a test flight. Credit Christian Haas, University of Alberta / Alfred Wegener Institute Usage Restrictions To be used in context with the press relaease. Terms and conditions of use: http://www.awi.de/en/news/images_video_audio/terms_of_use/ 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.