Antarctic Seas Record the Post-COVID-19 Era: Fossil Fuel Carbon Up 2.7 Times [Reading Science]

Analysis of Marine Sediments Near King Sejong Station
Evidence of Resumed Ship Traffic and Tourism Activity

A study has found that as the number of ships and tourists traveling to and from Antarctica has increased again since the COVID-19 pandemic, traces of human activity are rapidly accumulating in Antarctic waters. The proportion of black carbon from fossil fuel combustion found in seafloor sediments near the King Sejong Station in Antarctica has increased by 2.7 times compared to before the pandemic.

According to the Korea Polar Research Institute on July 1, an analysis of marine sediments near the King Sejong Station in Antarctica showed that the proportion of black carbon derived from fossil fuels rose from 6% in 2019 to 16% in 2023, an approximately 2.7-fold increase.

The Sejong ship conducting marine exploration in front of Marian Cove near the Sejong Station. Provided by the Korea Polar Research Institute.

Black carbon consists of fine carbon particles produced by the incomplete combustion of fossil fuels or wood. It is one of the primary climate change-inducing substances, second only to carbon dioxide (CO₂) in accelerating global warming. When black carbon accumulates on snow and glaciers, it increases the absorption of solar radiation and melts glaciers. In contrast, when it sinks into the sea, it can be preserved for thousands of years without decomposing.

Resumed Activities in Antarctica Clearly Reflected in Seafloor Sediments

The research team led by Dr. Ha Sunyong collected marine sediments from Marian Cove and Maxwell Bay on King George Island in Antarctica in both 2019 and 2023, and analyzed the concentration of black carbon and the ratio of carbon isotopes. Through this, the team tracked the sources of black carbon and the characteristics of its deposition in seafloor sediments.

The study found a significant increase in the proportion of black carbon originating from fossil fuels compared to pre-pandemic levels. The team attributed this to the normalization of operations at the King Sejong Station and the resumption of ship traffic and tourism following COVID-19. In fact, according to the International Association of Antarctica Tour Operators (IAATO), the number of Antarctic cruise tourists in the 2023-2024 season was about 43,000, which is approximately 2.3 times higher than the 2019-2020 pre-pandemic season.

In addition, the apparent age of black carbon in the sediments was estimated to be around 4,700 to 5,120 years. The researchers interpreted this as evidence that the shallow coastal waters and rapid sedimentation rates in Antarctica create a favorable environment for quickly burying black carbon on the seafloor, thus preserving it for long periods.

Different from the Arctic: Local Activity Has a Pronounced Impact in Antarctica

Marianne Soman collecting marine sediments. Provided by Korea Polar Research Institute

The team also conducted a comparative analysis of sediments from the Svalbard region in the Arctic Ocean off Norway. While more than half of the black carbon in the Arctic originated from outside sources—such as wildfires in mid-latitude regions—Antarctica exhibited a much stronger influence from local human activities.

Min Junoh, the first author of the study and a research fellow at the Korea Polar Research Institute, stated, "By identifying how black carbon moves and is preserved long-term in polar regions, we have gained crucial insights into its role in the polar carbon cycle."

The results of this research were published in the June issue of the international journal Environmental Science & Technology, which covers environmental science topics.

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