Cheongseokho Subglacial Lake Beneath 2.2 km of Antarctic Ice: Area and Structure Mapped for the First Time [Reading Science]

An Area Eight Times the Size of Yeouido, 120 m of Sediment Identified...
Laying the Groundwork for Ultra-Deep Drilling in 2029

The detailed structure of the subglacial lake “Cheongseokho,” hidden beneath 2.2 km-thick Antarctic ice, including its area, water depth, and sediment thickness, has been precisely identified for the first time using original technology developed by a Korean research team. With the completion of a “high-precision pre-survey map” for an ultra-high-difficulty drilling project planned for 2029, Korea’s capabilities in deep Antarctic exploration are being evaluated as having made a significant leap forward.

The Korea Polar Research Institute (KOPRI) announced that it has identified the detailed structure of the subglacial lake “Cheongseokho,” located about 270 km southeast of the Jang Bogo Antarctic Research Station, through seismic survey exploration. The research findings have been published in the international journal “The Cryosphere.”

Schematic diagram of Cheongseokho and analysis of seismic survey data. Provided by the research team.

A subglacial lake is formed when the base of a massive glacier melts under the pressure of the overlying ice and geothermal heat. Because it can remain isolated from the outside world for tens of thousands to tens of millions of years, it is often referred to as an “alien world within Earth.” Its environment is similar to that of Europa, where an ocean is believed to exist beneath the ice, making it one of the key analogue sites for the search for extraterrestrial life.

An Area Eight Times the Size of Yeouido... 120 m of Sediment Identified

The research team led by Dr. Kang Seunggoo conducted a detailed analysis of seismic survey data acquired on site between 2021 and 2022. Seismic surveying is a technique that identifies subsurface geological structures by generating artificial vibrations at the surface and interpreting the waves that are reflected back from underground.

The analysis showed that Cheongseokho lies beneath approximately 2.2 km-thick ice and has an area of 23 square kilometers, about eight times the size of Yeouido. Its water depth was confirmed to be at least 10 m. In particular, the lakebed is estimated to be covered by a sediment layer about 120 m thick.

Joo Hyuntae, a researcher at KOPRI, explained, “The 120 m-thick sediment layer is a repository that preserves records of past environmental changes in Antarctica, and it is also a potential habitat where unknown microorganisms that have survived in extreme conditions may exist.”

The name “Cheongseokho” is derived from “Cheongseok,” the pen name of former KOPRI Director Kim Yedong, who devoted himself to Korea’s early polar research. Kim served as the first Asian chair of the Scientific Committee on Antarctic Research (SCAR).

Location of the subglacial lake 'Cheongseokho'. Provided by the research team.

Beyond Overseas Cases Exceeding 1 km... Challenge of 2.2 km Drilling

The significance of this study lies in the fact that it has increased the likelihood of success for the drilling project scheduled for 2029. By precisely identifying in advance the internal structure and thickness of the ice and the boundary conditions of the lake, it is now possible to minimize errors in selecting the drilling location.

Drilling into subglacial lakes is a highly advanced technology that only a very small number of countries worldwide have attempted. Even the U.S. research team, regarded as a genuine success case, carried out its work in ice roughly 1 km thick. Drilling into Cheongseokho at a depth of 2.2 km is expected to be a challenge that goes beyond existing limits.

Based on these results, KOPRI plans to work with the Ministry of Oceans and Fisheries to push ahead with drilling at Cheongseokho in 2029.

KOPRI Director Shin Hyungcheol said, “Global competition is intensifying over the exploration of subglacial lakes, which are among the deepest and most secretive regions of Antarctica,” adding, “By being able to look into a subglacial lake in advance using our own technology, we have raised the probability of drilling success to a whole new level.”