[1] Max Planck Institute for Dynamics and Self-Organization, D-37073 Göttingen, Germany
[2] Department of Physics, Cornell University, Ithaca, NY 14853-2501, United States
[3] Department of Physics, University of California, Santa Barbara, CA 93106, United States
[4] Department of Earth and Planetary Sciences, Faculty of Chemistry, Weizemann Institute of Science, Rehovot, Israel