Researchers have discovered a potential site near South America that could harbor the oldest continuous ice record on Earth, dating back 1.5 million years. By analyzing marine dust, they are piecing together the planet’s complex climate history and unraveling the mysteries of the mid-Pleistocene transition.
Decoding Earth’s Frozen Past
The climate of the Earth has changed greatly and often over its almost 5 billion year history, so that it missed a lot centuries with polcni covered. Ice cores provide a unique sample of the atmosphere that can give insight into those past climates.
The oldest continuous ice core record — extending 800,000 years in Antarctica — has been of particular interest to researchers. But a new study, which analyzed samples taken from another International Ocean Discovery Program site close to continental South America called Site U1537, suggests that may just be the tip of the iceberg and there might be an even older record waiting beneath them – one spanning 1.5 million years.
Covering the sedimentology of Site U1537, marine dust records have been analyzed in a study published in the journal Climate of the Past. Through comparing this dust record with that of ice cores taken from the nearby region, researchers were able to develop a relationship and identify the location as a possible site for the world’s oldest ice.
The Mid-Pleistocene Transition Unraveled
Understanding these responses is a key reason for deep drilling efforts to tap the oldest ice, so that scientists can investigate what happened to climate cycling — why Earth’s rhythmic changes in temperature became much more pronounced after entry into the interval of roughly 100,000-year cycles during the mid-Pleistocene.
This is with the exception of around 1.2 million years ago when the planet was oscillating between glacial and interglacial periods every 41,000 years on average. But somewhere between 700,000 and 1.2 million years ago the cycles grew erratic, giving way to the Mid-Pleistocene transition.
Being able to explain this transition and the consequences of these feedbacks are essential for guiding our predictive skills into climate futures. Previous studies have offered up several hypotheses for potential explanations – from regolith erosion allowing thicker ice sheets to tectonic movements leading to glacial cooling – but this latest research might just help them figure out the real reason why glaciers grew as big and widespread as they did once upon a time.
The oldest ice, which offers a key to reading the similar treatment of Earth’s climate system during this important time, could give an explanation for what feed-back signals are at play in planetary systems (also called vehicles) and on preserved planets.
Conclusion
This find, announced in a paper in this week’s edition of the journal Science, could help to change the way we study these vital evidence of Earth’s ancient climate. The sediments at Site U1537 contain marine dust, which people have used to help determine Earth’s ancient climate history and the mystery of the mid-Pleistocene transition. As our investigation and decoding of this ancient ice continues, the secrets it contains may provide the key to decode the intricate workings of Earth’s climate and its profound impacts on a global scale.
