Scientists Have Found Some Truly Ancient Ice, But Now They Want Ice That's Even Older


It's chilly across the country today. Highs of just fifty eight in miami and sixteen in minneapolis which makes minnesota colder than an arctic as mcmurdo station but the cold weather doesn't last forever in the twin cities and in antarctica. It does ice their last hundreds of thousands even millions of years and as npr's nell greenfieldboyce reports that makes an arctic the perfect place to find some of the oldest ice in the world. Just how old is the oldest ice. On earth john higgins says. Nobody really knows you know. Would i be surprised at this point. We had five million-year-old is i mean. I'd be surprised. But not it's not unfathomable i think he and some colleagues recently collected ice samples in antarctica. That were later analyzed and shown to be as old as two point six million years. It's beautiful stuff when you pull out. The is it. Essentially as crystal clear accepted filled with tiny bubbles the bubbles contain air from when the ice formed and this trapped air is what scientists are really after higgins says if you want to understand how gases like carbon dioxide have affected the climate throughout history. You know you can't really do better other than getting a time machine and going back in time and taking an air sample then using these ice cores which physically just trap samples of ancient air to release that ancient air. All you have to do is melt the ice. That's the sound of a research camp manager in antarctica making drinking water by melting scraps of two hundred thousand year old ice in a metal pot to actually collect an analyze the release gases however ancient is has to melt in a lab. Sarah shackleton studies old princeton where she gets to watch the trapped air bubble out and that is something that i don't know if i'll ever get sick of watching. It's actually like pretty mesmerizing and one thing. That's released surprising every time to muse. Just how much gas is actually in the ice. She says it's a lot and samples from time. Periods undergoing past climate changes could be used to help make predictions about the future. One of the biggest questions in terms of kind of the modern warming and look anthropogenic. Climate changes helmich warming. Do should we expect with the amount of co two that we have in the atmosphere now. Antarctica has been covered by an ice sheet for at least thirty million years. But it's actually pretty hard to find really old ice. John gooch is a geologist. At the university of minnesota he says while snowfalls constantly add new layers of ice to the top of the ice sheet the oldest layers at the bottom can disappear. That's because of geothermal heat coming up from the ground so the rocks are giving off heat of slowly over time and so that has the potential to melt ice at the bomb. Still bits of super old ice like that two point six million year old sample can sometimes be preserved at the ice sheets edges the older snippets of ice. That we've been able to find come from places where the ice has flowed up against a mountain range and been exposed at the surface in those spots though. The ice can be all jumbled up and messy. It's not nice layers that have been laid down sequentially over a long continuous stretch of earth's history to get a neatly layered ice sample like that. Scientists need to drill straight down through the thick icesheet so far the oldest ice collected that way goes back eight hundred thousand years. Gooch says the goal now is to drill down a couple of miles to reach ice. That's older a million to two million years old whether or not we'll be able to find it at the bottom of the ice sheet where we can recover a relatively simple continuous record. Is i guess. That's the sixty four thousand dollar question at team from china has drilling underway a group from europe. We'll start in november. What everyone wants is i-i samples that cover a key time period about a million years ago. When there was a dramatic shift in the planet cycle of ice ages. Those had been coming every forty thousand years or so but for some reason that pattern ended and it changed to every one hundred thousand years instead unto us working on climate. That's a really big deal. Eric wolf is a climatologist with the university of cambridge in the united kingdom. It's a really big question as to why that change is fundamental tower climates. Work in a way you could say. We don't really understand today's climate. If we don't understand why we live in one hundred thousand year will draw the forty thousand year world. The coronavirus pandemic basically ruins the arctic research season. That would've been happening now but starting next fall researchers will be backed down there searching for really old ice nell greenfieldboyce npr news.

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