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Antarctica May Melt More Slowly Because of Gravity

ByAllison EckNOVA NextNOVA Next

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For all its barren frigidity, Antarctica is an exceedingly complex place. As climate change warms our planet, some of Antarctica’s ice is melting away—while other regions are becoming even icier. The dynamic interplay between these two processes is keeping scientists very busy.

But there might be yet a third factor.

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A new study published in Nature Communications argues that climatologists and policymakers can’t fully understand the condition of the Antarctic ice sheet without help from their colleagues in physics. The Earth’s irregular geology (consisting of mountains, rugged terrain, and so on) causes subtle variations in gravity throughout the globe; water, in such huge quantities, has the same effect: Antarctic ice is so heavy that it flattens the South Pole.

The Antarctic ice sheet is melting in some places and solidifying in others. The missing link in our understanding of how and why this is happening could be gravity.

Here’s Nathan Collins, writing for Pacific Standard:

What all that means is that, as the AIS [Antarctic ice sheet] melts, the land underneath it will rise and the AIS’s gravitational pull on the surrounding waters will decline, resulting in a lower sea level near the coasts of Antarctica. As that happens, the AIS will rise out of the water. But one of the main reasons the AIS is melting is because of contact with seawater, so as the sea recedes, the ice sheet will melt more slowly. In other words, the AIS might stick around longer—and the world’s oceans might rise less quickly—than previously thought. Depending on how much the Earth warms up, that could be enough to prevent, or at least delay, the complete collapse of the western reaches of the AIS, the team writes.

Antarctic melting may have other indirect, positive consequences—for example, it could slow climate change by turning nearby seas into carbon sinks. But overall, scientists need a much more thorough understanding of the relationship, geophysically speaking, between sea level rise and gravity to be certain of these effects.

Photo credit: NASA