Antarctic Ice Threatens Meteorite Accessibility Due to Climate Change, Study Finds

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Maria Valdes, a research scientist at the Field Museum of Natural History and the University of Chicago, is drawn to the icy plains of Antarctica as a magnet for meteorite hunters. Every year, around 1,000 space rocks are discovered in the region, their dark color standing out against the white landscape.

Antarctica, known as an icy desert, is a perfect place to find meteorites. Valdes, a member of an expedition team in late 2022 and early 2023, visited the region for her work at the museum's Robert A. Pritzker Center for Meteoritics and Polar Studies. During the expedition, the international team discovered five meteorites.

While exploring, they came across a large brown stone in the middle of an ice field. The rock was slightly smaller than a bowling ball and weighed 7.6 kg (about 17 pounds). Valdes mentioned that despite handling many meteorites in her career, finding one herself brought a unique and special feeling.

Meteorites are vanishing into the Antarctic ice due to the climate crisis, according to a recent study. Sampling of ice is being done in a blue ice area as part of the 2022 Chilean Antarctic Institute field mission.

Meteorites, formed from celestial bodies like the moon, Mars, and large asteroids, hold valuable information about the solar system's history. Each meteorite tells a fascinating story about how our solar system came to be.

However, a recent study warns that the climate crisis is posing a threat to these precious meteorites. Due to the melting ice, meteorites are vanishing and becoming inaccessible to scientists.

Antarctic rocks are sinking into the ice at a faster rate as the climate warms. This will eventually make many meteorites inaccessible to scientists, according to Valdes, who was not part of the latest research. These meteorites are important time capsules that provide clues about the history of our Solar System.

A recent study published in the journal Nature Climate Change reveals that approximately 5,000 meteorites could vanish from the melting ice sheets each year as Earth continues to warm. Antarctica has been a significant source of meteorite discoveries, with over 48,000 specimens found so far, representing about 60% of all meteorites found worldwide.

West Antarctica — home to the Thwaites Glacier, also known as the "Doomsday glacier" — is the continent's largest contributor to global sea level rise.

West Antarctica — home to the Thwaites Glacier, also known as the "Doomsday glacier" — is the continent's largest contributor to global sea level rise.

Jeremy Harbeck/OIB/NASA

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How to find a meteorite

Meteorites, rocks that come from space and fall through Earth's atmosphere, do not land evenly across the frozen continent. Instead, they tend to concentrate in certain areas due to geography and weather patterns, according to Valdes.

These meteorites are often found in blue ice fields. In these regions, a combination of ice movements and weather conditions strip away layers of snow and ice, revealing meteorites that were previously hidden within the ice. The ice in these areas appears blue compared to the surrounding snow.

"Phenomenal concentrations of meteorites can develop over significant stretches of time, sometimes reaching as high as 1 per square meter in certain locations," she explained.

Scientists carve out a meteorite submerged under the ice during a 2009-2010 field mission to Antarctica's Balchenfjella.

Scientists carve out a meteorite submerged under the ice during a 2009-2010 field mission to Antarctica's Balchenfjella.

Steven Goderis/Vrije Universiteit Brussel

Researchers have often stumbled upon areas of blue ice rich in meteorites by chance. However, Veronica Tollenaar, a doctoral researcher at Université Libre de Bruxelles in Belgium, and her team decided to take a more organized approach. They utilized a machine-learning algorithm to develop a "treasure map" of potential meteorite-rich zones. This map was created based on various factors such as surface temperature, slope, cover, and ice flow movement.

Their findings, which were published in the journal Science Advances in January 2022, pinpointed 600 specific zones as potential hotspots for meteorites. The researchers estimated that around 300,000 meteorites could still be found on the surface of the ice sheet. In 2023, Valdes and her colleagues utilized this valuable information to determine the best locations to focus their search efforts during their expedition.

Valdes mentioned that based on their experience, Tollenaar's approach has only been successful to a certain extent. It is important to also take into account local factors like topography and wind directions, which can move meteorites from blue ice fields to specific meteorite traps.

In the recent study, Tollenaar and her team projected the potential loss of meteorites under various climate change scenarios by integrating climate modeling with their previous research from 2022.

A scientist holds a piece of the ice core extracted from West Antarctica showing air bubbles.

A scientist holds a piece of the ice core extracted from West Antarctica showing air bubbles.

University of Cambridge/British Antarctic Survey

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Meteorites are able to penetrate the ice, even in temperatures below freezing. The dark color of the rock absorbs solar radiation, causing it to heat up and melt the surrounding ice. This heat can then melt the ice locally, causing the meteorite to gradually disappear from the surface.

Harry Zekollari, co-lead author of the study with Tollenaar, explained that a cold surface temperature is one of the factors associated with a possible meteorite cluster. According to Zekollari, who is an associate professor of glaciology at the Vrije Universiteit Brussel, maintaining a consistently cold surface temperature is crucial. Even a slight change from -12°C to -9°C can lead to the loss of meteorites as it crosses a critical threshold.

A meteorite lies partially in the ice in contrast with most samples collected while on the surface.

A meteorite lies partially in the ice in contrast with most samples collected while on the surface.

Under current policies, researchers predict that around 28% to 30% of the meteorites in Antarctica could become unreachable due to a temperature rise of 2.6 to 2.7 degrees Celsius (4.7 to 4.9 F) above preindustrial levels. In a worst-case scenario with high emissions, this estimate jumps to 76%.

According to the study, only at elevations higher than 2,500 meters (8,202 feet) will the loss of meteorites be less than 50%.

Matthias van Ginneken, a research associate at the University of Kent’s Centre for Astrophysics and Planetary Science in the UK, mentioned that the findings were logical given the impact of global warming on Antarctica.

exp Antarctic ice sheet melt Holmes Wolff INTV 021102ASEG2 cnni climate_00004401.png

exp Antarctic ice sheet melt Holmes Wolff INTV 021102ASEG2 cnni climate_00004401.png

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Van Ginneken, not part of the study, mentioned that he would have liked to see more discussion on uncertainties in the model and lab experiments mimicking the impact of global warming on meteorites to back up the algorithm's results.

In an email, he expressed concern about the findings but noted that there are still thousands of meteorites waiting to be discovered each year.

What we have discovered from studying Antarctic meteorites is that the main concern lies in the logistical challenges of finding them. Currently, it is already a tough task due to the remote location of Antarctica. If the findings of this research hold true, scientists may need to venture into new territories, possibly even farther from their usual scientific bases. This would make the search for these meteorites even more difficult and require additional funding and logistical assistance.

Meteorites found in the most southern parts of Earth have provided valuable insights, according to Kevin Righter, a planetary scientist at NASA's Johnson Space Center in Houston. In a commentary published with the research, he mentioned that he was not part of the study.

The size of a basketball, this meteorite landed in southeastern England in February 2021.

The size of a basketball, this meteorite landed in southeastern England in February 2021.

Jonathan E.Jackson/NHM Photo

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Scientists identified meteorites found in the area in 1979 and 1981 as coming from the moon. Before these discoveries, the only moon samples were from the Apollo and Luna landing sites. The meteorite samples have allowed for a broader and more thorough examination of the entire lunar surface. Some other meteorites have also been linked to Mars.

Recent research suggests that as more meteorites are collected, new types are likely to be discovered. This could potentially include fragments from Mercury or Venus that were ejected from their surface after impacts.

Righter, together with the researchers, urged for an increase in collection efforts and for them to be given more importance. He emphasized the importance of collecting meteorites promptly to ensure they remain a valuable resource for current and future planetary science.

Editor's P/S:

The article highlights the significant threat posed by the climate crisis to the preservation of meteorites in Antarctica. As the ice melts due to rising temperatures, meteorites are disappearing into the depths, making them inaccessible for scientific study. This poses a serious challenge to scientists who rely on these extraterrestrial rocks to gain valuable insights into the history and composition of our solar system. The potential loss of meteorites due to climate change underscores the urgent need for immediate action to mitigate its effects and protect these priceless scientific resources.

Furthermore, the article discusses the innovative approach developed by researchers to identify potential meteorite-rich zones in Antarctica using machine learning algorithms. This approach has the potential to significantly improve the efficiency of meteorite hunting expeditions, leading to the discovery of new and potentially unique specimens. However, it is important to note that while this technology is a valuable tool, it should be used in conjunction with local knowledge and expertise to optimize search efforts and maximize scientific outcomes. The combination of cutting-edge technology and human experience will be crucial in preserving and studying meteorites in the face of the challenges posed by climate change.