1. Department of Earth Sciences; University of Oregon; Eugene Oregon USA
2. Applied Physics Laboratory; University of Washington; Seattle Washington USA
3. Bristol Glaciology Centre, School of Geographical Sciences; University of Bristol; Bristol UK
4. Institute for Geophysics; University of Texas; Austin Texas USA
5. Department of Geology; University of Texas; Austin Texas USA
6. College of Earth, Ocean, and Atmospheric Sciences; Oregon State University; Corvallis Oregon USA
7. Department of Geology; University of Kansas; Lawrence Kansas USA
8. Institute for Marine and Atmospheric Research Utrecht; Utrecht University; Utrecht Netherlands