The Discovery of Ancient Glacial Ice on Bylot Island
On the remote expanse of Bylot Island, nestled within Canada’s Nunavut Territory in the Arctic, researchers have unearthed a remarkable discovery: the remnants of an ancient glacier, potentially exceeding a million years in age. This finding marks a significant moment in glaciology, representing what could be the oldest glacier ice ever discovered buried within permafrost, a layer of ground that remains frozen for a minimum of two consecutive years. This discovery, reported in the January 1 issue of Geology, holds immense promise for scientists seeking to unravel the mysteries of past climates. However, the relentless march of human-induced climate change poses a dire threat, exposing this long-preserved ice to the risk of melting and jeopardizing the invaluable information it holds.
Glacier Ice as a Climate Archive
Glacier ice acts as a natural time capsule, preserving within its frozen layers a wealth of information about past atmospheres and climates. Like entries in a meticulously kept logbook, the air bubbles, chemical compounds, and particulate matter trapped within the ice provide scientists with clues to decipher the environmental conditions of bygone millennia. However, instances of discovering ice older than the last major ice sheet expansion, which occurred between 26,000 and 20,000 years ago, are exceedingly rare. The newfound ice on Bylot Island offers an unprecedented opportunity to delve into the climate of the early Pleistocene epoch, a period marked by cyclical ice ages interspersed with warmer interglacial periods. These past climate shifts serve as valuable analogs for understanding potential future climate scenarios, emphasizing the significance of this discovery.
The Serendipitous Discovery
The path to this remarkable discovery was paved by serendipity. In 2009, a team of researchers led by geomorphologist Daniel Fortier of the University of Montreal was engaged in studying a buried fossilized forest on Bylot Island. During their fieldwork, they encountered the aftermath of recent landslides triggered by the thawing of permafrost. These landslides had exposed translucent, layered bodies of ice buried a few meters below the surface, just above the fossilized forest. Radiocarbon dating of organic matter within the ice yielded astonishing results, revealing an age exceeding 60,000 years, far surpassing Fortier’s initial expectations.
Dating the Ancient Ice
Further investigations revealed compelling evidence pointing to an even greater age for the ice. Within the sediment layers overlying the ice, researchers identified a reversal in the alignment of magnetic minerals, coinciding with a known reversal of Earth’s magnetic field approximately 770,000 years ago. This provided a minimum age estimate for the ice. The fossilized forest upon which the glacier rested, previously dated to between 2.8 and 2.4 million years ago, established a maximum possible age, further narrowing down the timeframe for the ice formation.
The Resilience of Permafrost
The preservation of this ancient glacier ice for hundreds of thousands of years highlights the remarkable resilience of permafrost. Despite climate projections suggesting widespread thawing of permafrost by the end of the century, this discovery serves as a testament to its enduring nature. The fact that the glacier ice has survived past interglacial periods warmer than the present suggests that the permafrost system may be more resilient than previously thought, offering a glimmer of hope in the face of a changing climate.
Implications and Future Research
The discovery of this ancient glacier ice on Bylot Island opens up exciting avenues for future research. Analysis of the trapped air bubbles will provide valuable insights into the composition of Earth’s atmosphere during the early Pleistocene, shedding light on greenhouse gas concentrations and their influence on past climates. Studying the chemical composition of the ice can reveal information about past temperatures, precipitation patterns, and atmospheric circulation. The particulate matter trapped within the ice can provide clues about volcanic eruptions, dust storms, and other environmental events. Further research on this ancient ice promises to enhance our understanding of past climate variability and inform projections of future climate change. However, the race against time to analyze this invaluable archive before it succumbs to melting underscores the urgency of addressing climate change.
