Earth has witnessed several episodes of climatic changes over millions of years. Ice has formed a major part of it and is like a valuable time capsule that can help understand the climate during different time periods. It has proliferated across the planet at different points in time and has preserved dust and debris preserved through millennia.
Using this as a starting point, scientists are now trying to find the world’s oldest ice.
Right now, the oldest known continuous ice record from Antarctica is 800,000 years old. However, now an international partnership of scientists is working to increase this to 1.5 million years.
However, it is hard to locate the exact place where scientists can find the oldest ice since glaciers move across land, and basal melting can eradicate records.
But, as per research published in Climate of the Past, the International Ocean Discovery Program Site U1537 near South America might be a ripe candidate for dating Oldest Ice. This is based on its marine dust content.
To finalise the best candidate, researchers compared marine dust in southern Atlantic Ocean ice cores from Ocean Drilling Project Site 1090 with those of Site U1537. Dr. Jessica Ng, of Scripps Institution of Oceanography, US and colleagues found Site U1537 to be the most appropriate marine dust record which was then compared to the ice dust of Epica Dome C on Antarctica.
They also created artificial Oldest Ice records and matched the patterns with the Site U1537 marine dust record.
They found that the records for the two sites matched up to 800,000 years ago. But the correlation reduced after that which may indicate spatial variability of dust influx across the southern hemisphere during the 40,000-year world scenario.
Meanwhile, another reason for finding the oldest ice is to understand why the mid-Pleistocene transition happened and what the consequences were.
