Did you know that Earth's glaciers have a pulse? It's true—and it's more complex than you might think. From the towering Saint Elias Mountains in Alaska to the rugged Karakoram range in Pakistan, glaciers aren't the static, unchanging giants they appear to be. Instead, they speed up and slow down with the seasons, responding to the ebb and flow of temperature changes in ways that are both fascinating and deeply concerning. But here's where it gets controversial: while some glaciers follow predictable patterns, others behave in ways that challenge our understanding of how they'll respond to a warming planet. And this is the part most people miss: these seasonal pulses might hold the key to predicting which glaciers are most at risk of disappearing.
In a groundbreaking study published in Science in November 2025, NASA scientists Chad Greene and Alex Gardner analyzed millions of satellite images collected between 2014 and 2022 to map global glacier movement. Their findings reveal a stunning diversity in how glaciers respond to seasonal warming. For instance, Alaska’s Malaspina Glacier—the world’s largest piedmont glacier—typically speeds up in spring as meltwater lubricates its base, only to slow to a crawl by winter. But in the Arctic regions of Europe and Russia, glaciers often peak in speed during summer or early fall. Why the difference? It all comes down to how meltwater interacts with the glacier’s bed, reducing friction and allowing the ice to slide more easily.
But not all glaciers follow this script. Take the Barnes Ice Cap on Baffin Island in the Canadian Arctic. This relic of the Laurentide Ice Sheet barely moves for most of the year, then suddenly accelerates when meltwater finally arrives in summer. In contrast, Pakistan’s Baltoro Glacier experiences a gradual speedup that begins high up and slowly moves downward as the melting season progresses. These variations aren’t just curiosities—they’re critical clues about how glaciers will fare in a warmer world.
Here’s the kicker: Greene and Gardner found that glacier flow accelerates with every degree of warming, and these seasonal patterns are linked to long-term changes. In other words, spring and summer speedups could serve as early warning signs of a glacier’s resilience—or lack thereof—to prolonged warming. As Greene puts it, ‘We measured their pulse. Now we just need to keep an eye on their temperature.’
But here’s the controversial question: Are we doing enough to monitor these changes? With over 200,000 glaciers worldwide, the task is daunting. And while satellite technology has given us an unprecedented view, it’s up to us to act on what we learn. Do these seasonal pulses signal a temporary adaptation, or are they the first signs of irreversible decline? Let us know what you think in the comments—this is a conversation we can’t afford to ignore.
