In Hobart’s cold lab, where temperatures drop to –20 °C, scientists from the Australian Antarctic Program are analyzing the first ice core samples from their “Million Year Ice Core” project. These one-meter ice cylinders, taken from 150 meters deep on the Antarctic Plateau, contain tiny air bubbles that hold Earth’s atmosphere from 4,000 years ago. Although these initial samples are just the beginning, they are crucial for paleoclimate research. This marks the start of a deeper exploration, aiming to reach over 3,000 meters below the ice surface, potentially revealing Earth’s climate history up to two million years back.
From the Icefield to the Freezer
Australian researchers used various transport methods to move valuable samples from Antarctica to Australia. The samples traveled on icebreaker ships and aircraft, arriving at Hobart’s Antarctic Processing Facility. There, glaciologists and technicians, dressed in heavy parkas and gloves, moved the ice sections into a sub-zero freezer lab. Dr. Joel Pedro, the lead paleoclimatologist from the Australian Antarctic Division, declared, “In the freezer lab today, we’re cutting the first samples from the ‘Million Year Ice Core.’” This marks a significant milestone for the team.
The Science Behind Ice Cores
Ice cores are crucial records of Earth’s climate and atmosphere. As snow turns into ice over time, it traps air bubbles, preserving past atmospheres. By examining greenhouse gases like carbon dioxide and methane, and isotopic ratios of oxygen and hydrogen, scientists can accurately trace temperature changes, volcanic eruptions, and ocean circulation shifts.
Why the ‘Million Year’ Ambition Matters
Current ice core records date back 800,000 years, revealing nearly a million years of glacial cycles. Yet, the Mid-Pleistocene Transition, a period around a million years ago, remains a mystery. During this time, ice-age cycles shifted from 40,000 to 100,000 years. Scientists aim to extend ice core records beyond this transition to uncover the causes of this major climate shift. Dr. Pedro stated that pushing climate records back over a million years, possibly up to two million, could solve a major puzzle in paleoclimate science.
Project Origins and Site Selection
The “Million Year Ice Core” project started almost ten years ago, uniting the Australian Antarctic Program with global partners. After thorough studies, they chose Dome C North, 1,200 km from Casey Station, at 3,000 meters high. This isolated plateau has very slow ice movement and little surface melting, perfect for keeping ancient ice intact. Using satellite data and radar, they confirmed that the ice there might be over two million years old at depths beyond 3,000 meters.
Logistical Feats: The Antarctic Traverse
Setting up a deep-field drilling site in a harsh environment required immense effort. In the summer of 2024–25, a tractor convoy transported nearly 600 tonnes of drilling gear, living quarters, fuel, and food from Casey Station to Dome C North over 18 days. Led by Chris Gallagher from AAD, a team of ten faced blizzards and surface cracks. Gallagher noted, “This was our program’s largest traverse ever. Success depended on technical skills, camaraderie, and mutual support—real teamwork in extreme conditions.
Drilling and Core Retrieval
In just ten days, a drill shelter was built, and a science team arrived to start ice coring. Chelsea Long, a field assistant, found the first ice core’s emergence deeply moving, describing it as a “real joy” to see and touch the ice layers. Each ice core was quickly stored in insulated boxes to avoid damage and contamination. Samples for gas and isotope analysis were precisely cut, while those for physical studies, like crystal structure and dust content, were documented and stored.
Initial Laboratory Procedures
In Hobart’s lab, researchers cut ice cores into slabs using band saws and microtomes. Special chambers extract gas bubbles in a vacuum, and gas chromatography measures CO₂, CH₄, and N₂O levels. Nearby cold rooms contain mass spectrometers that precisely determine stable-isotope ratios like δ¹⁸O and δD. Initial checks ensure sample integrity by examining fracture patterns, ice texture, and impurities. Dr. Pedro states, “These results will calibrate age-dating models and guide future drilling strategies.
Early Findings and Calibration
Preliminary isotopic measurements confirm the 4,000-year-old ice’s timeline. Tiny particles like volcanic ash and cosmic spherules provide extra markers. Researchers will compare this data with cores from other Antarctic sites, like Dome F and EPICA at Dome C, to create a unified climate history.
The Road Ahead: Drilling to Depth
The aim is to drill over several austral summers to reach 3,000 meters by the 2028–29 season. This depth will uncover ice nearly two million years old, providing the longest continuous climate record. To achieve this, operations must be extended, drill systems maintained and upgraded, and logistics for ice transport and storage ensured.
Implications for Climate Science
The “Million Year Ice Core” data will revolutionize our understanding of climate change. By analyzing greenhouse gases from key historical periods, scientists can improve carbon cycle models and confirm climate change predictions. Studying past rapid climate changes, like Dansgaard–Oeschger events, will help us understand current climate tipping points. Dr. Pedro noted that this record will be a crucial reference for atmospheric changes over a significant part of Earth’s history.
International Collaboration and Funding
Australia leads in polar science, backed by government funding and partnerships with the EU’s Beyond EPICA and the U.S. National Science Foundation. Collaboration and data sharing with global teams create a climate archive that aids worldwide scientific research.
Public Engagement and Education
The Australian Antarctic Division has unveiled an online portal for public engagement in climate research. This platform offers interactive visualizations of ice-core layers, greenhouse-gas timelines, and virtual tours of the drilling site. Schools can join live Q&A sessions with field scientists, and selected ice-core sections will be displayed in museums across Australia to inspire future polar researchers.
Conclusion
The arrival of the first 150-meter ice cores in Hobart marks the beginning of the “Million Year Ice Core” project. Scientists aim to delve deeper into Antarctica to answer questions about Earth’s climate history and enhance future predictions. From the cold labs to the vast Dome C North, this mission showcases human curiosity and determination against nature’s harshest conditions. Every meter drilled and bubble analyzed brings us closer to understanding how Earth has endured—and will endure—over time.
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