Over the course of our planet’s history, glaciers have come and gone. At one point, glaciers extended across all of what is modern-day Canada and down into much of the present-day United States. We see traces of these glaciers in the distributions of rocks and boulders on the landscapes and in the twisted terrain they left behind.
While being able to see glacial structures isn’t new, the diversity we’re able to see today is expanding as new glaciers melt and reveal the ground beneath. This is one of the weird opportunities we get thanks to climate change, and the structures being revealed are discussed in a new article in Reviews of Geophysics that summarizes 200 years of structural glaciological investigations. This article was written by Stephen Jennings and Michael Hambrey.
Glacial melting is revealing landscapes never before seen that capture the history of our planet. In Alpine valleys, researchers can now see the scars of the “Little Ice Age” that spanned from the 1300s to about 1850. In Svalbard, the terrain looks like corrugated cardboard from how the layered glacial structures have melted away. Greenland, in particular, is covered in ice sheets and glaciers, and its melting will be one of the largest contributors to global sea-level rise; already Greenland’s melting has revealed landscapes likely never seen by human eyes.
And in studying the ice that is still there in Greenland, researchers have discovered one small thing to celebrate: it turns out that our warming world may trigger weather patterns that are capable of dumping more snow onto Greenland’s mountains – snow that can start to build new glaciers. New research, led by Matthew Osman and appearing in Nature Geoscience, describes how historically, it has snowed more on Greenland’s peaks during warmer weather – weather that is warmer but not too much warmer – than it has during extreme cold.
Anyone who grew up in a snowy region knows that it can be too cold to snow and that the nastiest snowstorms occur when it is only a few degrees below zero. This past week, a massive amount of snow was dumped on Greenland by Hurricane Larry, and there is hope that such climate-change-driven storms of the future may allow new glaciers to begin to grow at high altitudes. This won’t save our world from climate change, but it does offer some small hope that there will still be glaciers to study in the future.
“Structures and Deformation in Glaciers and Ice Sheets,” Stephen J. A. Jennings and Michael J. Hambrey, 2021 July 27, Review of Geophysics
Woods Hole press release
“Abrupt Common Era hydroclimate shifts drive west Greenland ice cap change,” Matthew B. Osman et al., 2021 September 9, Nature Geoscience