[Reading Science] 200 Years of Atmospheric Records: The "Glacier of Fate"

Polar Research Institute Araon Expedition Team Completes Antarctic Research This Year
Successful Drilling of Swaitz Deep Glacier
World's First Proposal of New Mechanism Melting Swaitz Ice Shelf

Since Roald Amundsen first reached the South Pole in 1911, countries around the world have been competing to study Antarctica. Why is this? While it is partly to prepare for potential territorial disputes and to secure resources distributed in Antarctica, it is also crucial to gain clues to prevent climate change and the consequent collapse of Antarctic glaciers.

Our research team has also been actively expanding its presence in Antarctica. The Korea Polar Research Institute (KOPRI) researchers aboard the icebreaker Araon have explored Antarctica every year from around October, departing from Korea, until returning in May. Since Araon’s first Antarctic expedition in 2010, it has headed to Antarctica annually without fail.

Icebreaking Research Vessel Araon

This expedition also yielded significant research achievements. In particular, successfully drilling glaciers for the first time in isolated areas of Antarctica without the support of a research station is considered highly meaningful.

Dr. Han Young-chul’s research team at KOPRI, in collaboration with international teams from the University of Minnesota, USA, and the National Centre for Polar and Ocean Research, India, drilled two glacier sites near the Canisteo Peninsula in West Antarctica’s Thwaites Glacier area last January, obtaining 150-meter-long ice cores from each site.

Polar snow does not melt even during summer but accumulates and turns into ice at depths of 60 to 100 meters. The ice formed in this way preserves the air from the time of snowfall in the form of bubbles. By analyzing this, researchers can learn about past atmospheric composition and environmental conditions. For this reason, researchers collect “ice cores,” known as “frozen time capsules” of Earth’s atmospheric changes.

While our research team drilled ice cores near the Jangbogo Scientific Base in Antarctica, access to glaciers urgently requiring study has been difficult, causing delays in research.

Comprising eight members including scientists, drilling technicians, and safety personnel, Dr. Han Young-chul’s team succeeded in drilling ice cores from Thwaites Glacier, known as the “Doom’s Day” glacier because it is melting fastest in Antarctica and its disappearance could trigger a chain collapse of West Antarctic glaciers. This is the first time our team has attempted and succeeded in glacier drilling supported only by a research vessel rather than a scientific station.

This ice core drilling was conducted as part of the Ross-Amundsen Ice Core Array (RAICA) project, jointly promoted by KOPRI, the University of Minnesota, and the National Centre for Polar and Ocean Research, India.

Thwaites Glacier is difficult to access due to the absence of nearby stations. Therefore, the icebreaker Araon approached close to the research area, and the team transferred to a helicopter to reach the site. While January is midwinter in the Northern Hemisphere, it is midsummer in the Southern Hemisphere, where seasons are reversed. The warming West Antarctic seas during summer cause large ice shelves to break apart frequently, making icebreaker navigation challenging.

The ice cores secured by the expedition team are estimated to contain atmospheric records from the past 200 years. KOPRI plans to use these ice cores, obtained from one of the most climate-sensitive regions in Antarctica, to precisely reconstruct environmental changes since industrialization. The ice cores are stored in Araon’s freezer and are expected to arrive in Korea in May.

Dr. Han Young-chul, lead researcher at KOPRI, commented, “Although the opportunity for this expedition was hard-won, completing the mission under harsh conditions such as strong winds exceeding 30 m/s and heavy snowfall was not easy.”

Lee Won-sang, lead researcher overseeing the Araon West Antarctica expedition, said, “Successfully drilling glaciers in areas inaccessible from stations has allowed South Korea’s polar research capabilities to take a significant leap forward.”

KOPRI’s research team also succeeded in exploring glaciers with a thickness of 3,500 meters using radar technology developed by us during Antarctic research. Glaciers thicker than 3,000 meters are estimated to contain atmospheric information from at least 1.5 million years ago.

Dr. Lee Joo-han’s team, in collaboration with the University of Alabama, USA, explored Dome C in the Antarctic interior at the end of last year using a deep ice-penetrating radar they developed. Dome C is known as one of the locations with the thickest glaciers in Antarctica and is about 1,300 km away from the Jangbogo Scientific Base.

The research team obtained visual data that allowed them to confirm not only the glacier layers but also the structure of the Antarctic continent beneath the glacier and the presence or absence of subglacial lakes. The team plans to analyze and supplement the data and select candidate sites for deep ice drilling over the next three years.

Field exploration results are leading to research outcomes. Recently, KOPRI succeeded in identifying the cause of the collapse of ice shelves that prevent Antarctic glaciers from disappearing.

An ice shelf is a several-hundred-meter-thick “ice wall” that remains connected to glaciers even after they flow into the sea. It slows the speed at which continental glaciers flow into the ocean and blocks warm seawater from outside.

Dr. Park Tae-wook of KOPRI, along with an international joint research team from Hokkaido University, Japan, and Seoul National University, used the latest ocean modeling techniques that simulate the sea on computers to confirm that the Thwaites Ice Shelf is melting due to vortices occurring on the seabed. These vortices bring warm deep water, which flows from the north into the Antarctic coast, up to the underside of the ice shelf, causing it to melt.

Schematic diagram of the Amundsen Sea current reproduced through modeling. The direction of the current (yellow arrows), warm water temperature at depth (red color), and depth (500m and 700m indicated by black lines) can be observed.

Previous studies attributed the inflow of warm seawater into ice shelves mainly to strong winds blowing over the Antarctic sea surface. However, this study confirmed that the interaction between ocean currents and seabed topography is the primary cause supplying warm water to the ice shelf. This research was published in the April issue of the internationally renowned journal Nature Communications.