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

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Moreau, Ludovic, Weiss, Jérôme, Marsan, David
• Other Authors: Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement IRD : UR219-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: monitoring; sea ice; seismic noise; [SDU]Sciences of the Universe [physics]; Arctic; Arctic Ocean; Svalbard; Sea ice
• Online Access: https://insu.hal.science/insu-03594474; https://insu.hal.science/insu-03594474/document; https://insu.hal.science/insu-03594474/file/JGR%20Oceans%20-%202020%20-%20Moreau%20-%20Accurate%20Estimations%20of%20Sea%25E2%2580%2590Ice%20Thickness%20and%20Elastic%20Properties%20From%20Seismic%20Noise%20Recorded.pdf; https://doi.org/10.1029/2020JC016492

International audience 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; https://doi.org/10.1029/2019JC015709 ) where about 50 sensors were used, the number of geophones is reduced by 1 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 3-5 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.