Accurate estimations of sea‐ice thickness and elastic properties from seismic noise recorded with a minimal number of geophones: from thin landfast ice to thick pack ice

Ludovic Moreau (1) , Jérôme Weiss , David Marsan

1 ISTerre - Institut des Sciences de la Terre

Despite their high potential for accurate sea ice properties estimation, seismic methods are still limited by the difficulty of access and the challenging logistics of polar environments. Conventional seismic methods generally require tens of geophones together with active seismic sources for monitoring applications. While this is not an issue for mainland environment, it is restrictive for sea ice and prevents long‐term monitoring. We introduce a method to estimate sea ice thickness and elastic properties from passive recordings of the ambient seismic field with a minimal number of geophones. In comparison with our previous work (Moreau et al, 2020), where about 50 sensors were used, the number of geophones is reduced by one order of magnitude, thanks to a new strategy of inversion of the passive seismic data. The method combines noise interferometry for estimating the elastic properties, with a Bayesian inversion of the dispersion in the waveforms of icequakes for inferring ice thickness, based on passive recordings from only 3 to 5 geophones, depending on the signal to noise ratio. We demonstrate its potential both on data recorded on thin landfast ice in Svalbard, and on data recorded on thick pack ice in the Arctic ocean.

Domaines: Géophysique [physics.geo-ph]; Acoustique [physics.class-ph]

Ludovic Moreau, Jérôme Weiss, David Marsan. Accurate estimations of sea‐ice thickness and elastic properties from seismic noise recorded with a minimal number of geophones: from thin landfast ice to thick pack ice. Journal of Geophysical Research. Oceans, 2020, ⟨10.1029/2020JC016492⟩. ⟨hal-02986579⟩