Authigenic 10Be/9Be ratio from sediment core PS51/154-11, western Laptev Sea, Arctic Ocean

Authigenic 10Be and 9Be concentrations were measured from sediment core PS51/154-11 to reconstruct downcore authigenic 10Be/9Be ratio variations during deglacial period, and constrain the local ΔR by comparing it with ice-core 10Be records. The core was stored at −20 °C and temporarily warmed to 4 °C for subsampling. Sediment samples were collected at 5–10 cm intervals using syringes, and were freeze-dried and homogenized before analyses. Based on the age-depth model from Lin et al. (2025), 38 sediment samples from the depth interval between 50.5 and 450.5 cm depth were selected, allowing reconstruction during the time interval between 15 and 10 kyr BP. Sample preparation and both 10Be and 9Be measurements were conducted at 2024. Sediments were leached following the procedure described in Gutjahr et al. (2007), and beryllium was purified and processed following the protocol from Loftfield et al. (2024). Authigenic 9Be concentrations were measured with an Inductively coupled plasma atomic emission spectroscopy (Thermo Fisher Scientific Inc., ICP-OES-iCAP7400) at the Alfred Wegener Institute (AWI), Bremerhaven, Germany. While authigenic 10Be concentrations were measured with an accelerator mass spectrometry (AMS) at the DREAMS (DREsden AMS) facility, Germany (Lachner et al., 2023).