Uncovering the East Antarctic Fan Basin Province
Scientists have identified a massive fan-shaped geological formation buried under Antarctic ice, which they call the East Antarctic Fan Basin Province (EAFBP). This structure is believed to have formed before the breakup of the supercontinent Gondwana, potentially playing a role in how Antarctica split from Australia. The EAFBP lies beneath roughly half of the East Antarctic Ice Sheet, a frozen expanse that holds about 27 million cubic kilometers of ice.
If all that ice were to vanish, the land beneath would rise by as much as one kilometer. The giant feature’s geometry resembles a tectonic structure known as a sphenochasm, first described back in 1955. The fan’s ridges stretch along the coast for nearly 2,000 kilometers, and researchers note that many large subglacial valleys appear to radiate outward from a common hub near the South Pole.
Research Methods and Their Importance
To study this hidden structure, the team combined reconstructed rebound topography with data from radar, gravity, seismic, and magnetic surveys. As the researchers explain:
“Since these basins lie beneath roughly half of the East Antarctic Ice Sheet, they likely have a strong influence on both ice flow and landscape evolution, making them important for Antarctic glacial and hydrological processes.”
Interestingly, Antarctic sea ice began to shrink rapidly after 2015, and scientists described the ice loss in 2023 as record-breaking. Sea ice extent had remained stable since the late 1970s, and even saw a period of growth between 2007 and 2015. The timeline of this geological feature’s formation is difficult to pin down, and it may represent multiple episodes of expansion.
The discovery of the East Antarctic Fan Basin Province marks a significant step in understanding Antarctica’s geological past and its impact on global climate systems. This finding could help scientists better assess how changes in Antarctic ice cover might affect sea levels and climate conditions in the future. As sea ice continues to decline, studying such geological formations becomes increasingly relevant for predicting the consequences of global warming.