Visual stratigraphy of the BEOIC oldest-ice section – preliminary results from linescan images

During the main BEOIC processing campaign in 2025 at AWI, linescan images of double-sided polished ice slabs were routinely recorded. The linescanner is a well-established optical system in ice-core analysis that operates in darkfield mode, capturing scattered light from internal reflection surfaces and nuclei that are mostly associated with dust particles within the ice. The spatial resolution of the images is in the sub-millimetre range. As the measurement method produces almost no signal dispersion, it enables an exceptionally detailed view of small-scale layering.

In this contribution, we present images and grey-value records of the oldest-ice section between 2400 m and 2580 m depth and provide a preliminary interpretation of the observed features. Owing to the expected strong thinning—where more than 10,000 years may be compressed into a single metre of ice—these data offer a first indication of the limits of temporal resolution that can be achieved with other proxy parameters. Further image analysis addresses ice deformation as well as questions of stratigraphic integrity and continuity at the BEOIC site. We focus on selected depth intervals and present an initial overview of the evolution of lateral stability in the layered structures observed in the data.