Simulated evidence for ice over 1 Ma in the Dome A region, East Antarctica

Abstract. The search for Antarctic ice-core records older than 1 Ma is crucial for advancing our understanding of global climate change. However, basal melting and complex internal deformation within the Antarctic Ice Sheet make it extremely challenging to obtain continuous ice core records exceeding 1 Ma. In this study, we integrate ice core observations, radar transect constraints, and a pseudo steady state modeling framework to construct a high precision age model and evaluate the age of old ice in the Dome A region. Our simulations indicate extremely low basal melting (0.14 mm/yr) at Kunlun Station, and a maximum ice age of 1737 ± 223 ka, corresponding to low age density of 8.2 kyr/m. Considering the presence of basal melting, we adopt the age at 200 m above the bedrock as the maximum ice age, which yields an age 909 ± 113 ka and age density of 2.5 kyr/m, which is far lower than the maximum age density of 20 kyr/m required for high resolution climate reconstructions. Finally, we identify three potential locations where ice older than 1 Ma may be preserved, with the area north of Kunlun Station exhibiting both older ice and higher age density. This work demonstrates the generality and transferability of the Isoinv1D model, providing important support for Chinese deep ice core drilling program at Dome A and accelerating the IPICS effort to locate and recover million-year-old ice.