Sea ice mechanical property inference using cryophones and coherent signals

Abstract

Mechanical properties of Arctic sea ice can be inferred by observation of the speeds of compressional, shear and flexural waves generated through in-ice conversion of impulsive energy. In prior work, the impulsive signal was generated by a lead ball or sledge hammer dropped onto the top of the sea ice, and the inversion process required meticulous, manual extraction of signal amplitudes. The work presented here makes use of (a) coherent sources with which broadband signals can be generated to replace the manually generated hammer-drop signals and improve accuracy via matched filter, as well as (b) recent observations and modeling of ice sheet compressional resonances from which ice thickness can be more easily inferred. Analysis and modeling of observations from a recent field experiment in the Beaufort Sea are shown that demonstrate the potential capability of remote monitoring of sea ice mechanical properties.