Antarctica Yields Clues to Ancient Climate as Hidden Sediments Reveal Ice Sheet History
EAST ANTARCTICA – A new study reveals significant sedimentary deposits beneath the Antarctic ice sheet, offering insights into the preservation – and potential destruction – of ancient ice crucial for reconstructing Earth’s climate history. Researchers utilizing deep-penetrating radar,gravity,and magnetic field measurements across approximately 650 kilometers of Dome A have identified a distinct geological division. One area exhibits thick ice and irregular sediments, while the ”Elbow Complex” shows a thinner basal layer and smoother terrain.
The findings, detailed in a recent report, suggest that elevated heat flow and basal melting occurred over 34 million years ago, contributing to the observed sedimentation. In dome A, the basal layer can comprise up to 25% of the glacier’s total thickness, rapidly decreasing towards the basin’s center.
“Understanding how heat flow varies at the base of the ice sheet and what the temperature is like there is critical to finding places where older continuous ice can be preserved,” the researchers conclude.
The study underscores the importance of bedrock geology in preserving ancient ice,while also highlighting how sediment accumulation and melting can erase these vital climate records. Researchers suggest the area upstream of the South Pole Basin may offer improved preservation conditions, with future NSF COLDEX campaigns planned for locations like Allan Hills – where ice exceeding five million years old has already been found – and integration with European projects, including drilling at Little Dome C.
Detailed geophysical analysis of ice sheet structure and temperature is now considered essential before initiating new drilling efforts, according to the study. The research reinforces the complex interplay between ice,sediments,and heat flow in determining the potential for recovering million-year-old ice cores.
