High resolution monitoring of sea ice properties with Distributed Acoustic Sensing

To understand the response of sea ice to geophysical forcing, collecting field data remains essential. However, in situ monitoring of sea ice physical properties is challenging due to the complex logistics of the polar environment. Remote sensing methods such as Synthetic Aperture Radar (SAR) address some of these logistical constraints, but typically provide spatial information at regional scales and with temporal resolutions on the order of several days. While this is sufficient for large-scale monitoring, current sea ice models still struggle to accurately reproduce its decline, partly because small-scale processes are not adequately captured. Consequently, the next generation of models will require finer resolutions to describe local-scale ice–ocean interactions, especially in the context of the expanding Marginal Ice Zone (MIZ). This need is closely linked to our ability to observe small-scale sea ice properties so that breakup mechanisms associated with swell forcing can be better understood.

We introduce a methodology based on Distributed Acoustic Sensing (DAS) to recover small-scale variations in ice thickness and Young’s modulus. We test this approach on a dataset recorded in February 2025 on fast ice in the St. Lawrence Estuary (Canada). We demonstrate that sea ice properties can be estimated from both active and passive acquisitions on distances of the order of the km, with a spatial resolution of ~20 m.