State of the art
In an attempt to understand sea ice decline and to improve forecasting models, researchers focus mainly on 2 observables : thickness and extent (by satellite). Thickness measurements are very important because they provide an indicator of sea ice resilience, and currently they are performed mainly with 2 methods : sonar and radar. Both approaches are complementary, each with their strengths and weaknesses regarding costs, accuracy and practical implementation.
Sonar technology
Sonar methods rely on the use of an acoustic source moved underwater to probe the environment with acoustic waves. In this matter, military submarines have provided most of current knowledge on the general ice draft distribution (Percival et al., 2008, Rothrock et al., 2008). They allow accurate and rapid data to be recorded, but the currently available dataset relies on the declassification (...)
Radar technology
Radar methods require the use of an electromagnetic antenna moved above the surface of the ice. The electromagnetic wave propagates in the ice and is reflected at its boundaries. A profile of the ice thickness is thus obtained along the positions of the antenna. The accuracy of thickness estimation depends on the wavelength, but also on the ability to discriminate between echoes from actual (...)
An emerging approach : ambient seismic noise
In Geophysics, seismic waves have been used to image the Earth for decades. In particular, the emergence of “noise seismology” developed for the last decade in the PI’s team at ISTerre (Grenoble, France), proved a major breakthrough in seismology. This approach relies on passive recordings of ambient seismic noise to reconstruct the Green’s function of seismic waves propagating between sensors (...)
