Antarctica’s Ice May Be More Durable Than We Thought

Antarctica's Ice May Be More Durable Than We Thought

A study found that the East Antarctic Ice Sheet has survived higher temperatures than we’ve created.

Scientists studied the Pliocene epoch, which happened a few million years ago.

Temperatures were a little warmer then, so the epoch could be a good preview of a warmer Earth.

They found Antarctic ice was more prevalent back then than we’d believed. Which is a good sign but doesn’t mean humanity is off the hook.

One of the biggest potential dangers of increasing climate change is sea level rise caused by the melting of the polar ice caps. As our planet heats up, large ice sheets in Greenland and Antarctica will melt, potentially triggering several feet of increased sea level rise. If the entire Antarctic ice sheet melts into the ocean, it could lead to dozens of feet of sea level rise, likely enough to wipe out entire cities.

Of course, it’s important to remember that ice sheets are complex and predicting how they will react is difficult—there’s a wide range of possibilities. Perhaps the best way for scientists to predict how ice sheets will behave in the future is by learning how they behaved in the past, so one group of scientists traveled to the East Antarctic Ice Sheet to learn its history.

Specifically, the researchers were interested in what happened to the ice sheet during the Pliocene epoch, the geologic period from about 5.4 million years ago to around 2.5 million. During the Pliocene, global temperatures were a few degrees warmer than they are today, which means this era is a good model for what our world might look like in a few decades, if climate change remains unchecked.

To determine just what happened to the ice sheet during this period, the researchers drilled deep into the rock beneath it. The scientists were looking for samples of certain isotopes, beryllium-10 and aluminum-26. These particular isotopes are created from the impact of cosmic rays from space. When these cosmic rays hit the atoms in the soil, they trigger atomic reactions that produce these isotopes.

The key fact here is that cosmic rays can’t penetrate ice. If there was ice over the ground during the Pliocene, the cosmic rays wouldn’t have reached the ground and these isotopes shouldn’t be present in the soil. But if the ice sheet melted significantly, the researchers would find higher levels of these isotopes.

Mary Greeley News