Imagine a hidden force beneath Antarctica's icy waters, powerful enough to reshape our oceans and climate. That's exactly what researchers are uncovering: massive underwater tsunamis triggered by glaciers calving into the sea. An international team, spearheaded by the British Antarctic Survey (BAS), is diving deep—literally—to unravel this mysterious phenomenon. But here's where it gets controversial: these tsunamis, often towering several meters high, might rival the impact of wind and tides in mixing ocean layers, a process crucial for marine life and climate regulation. Could this overlooked force be a game-changer in our understanding of polar ecosystems?
When glaciers calve—a dramatic event where icebergs break off and plunge into the ocean—they don’t just create a splash. These events generate underwater tsunamis that churn ocean layers, blending heat, oxygen, and nutrients across depths. This mixing was long believed to be driven primarily by wind, tides, and surface heat loss. However, recent observations suggest these tsunamis play a far more significant role than previously thought, particularly in polar regions. And this is the part most people miss: their impact on redistributing heat might even surpass that of tides in certain areas.
The discovery of these tsunamis was serendipitous. During a BAS expedition aboard the RRS James Clark Ross, researchers led by Professor James Scourse from the University of Exeter collected data before, during, and after a calving event. Now, scientists at the Rothera Research Station on the Antarctic Peninsula and aboard the RRS Sir David Attenborough are doubling down on their efforts to understand these hidden waves.
Professor Michael Meredith, a BAS oceanographer leading the research, poses intriguing questions: Do different calving events produce varying tsunami intensities? How do seasonal changes influence their formation? And what does this mixing mean for polar climates and ecosystems? These are the puzzles his team aims to solve. Meanwhile, Professor Katy Sheen from the University of Exeter is co-leading a project to explore the diverse 'flavors' of tsunamis generated by glacial calving. “The fieldwork at Rothera is electrifying,” she shares. “We’re using remote cameras, underwater microphones, and autonomous vehicles to capture every detail of these events and their impacts on local chemistry and biology.”
The team is deploying cutting-edge technology, from real-time glacier imagery to underwater drones, to study even the most dangerous-to-reach locations. They’re also leveraging deep-learning algorithms and computer simulations to model how these tsunamis form and spread. Dr. Alexander Brearley, another BAS oceanographer, highlights their approach: “We’re achieving unprecedented detail in understanding how these tsunamis affect ocean temperature, nutrient distribution, and marine productivity—all vital for our planet’s health.”
But here’s the bigger picture: these tsunamis could have far-reaching consequences. Increased ocean mixing might pull warmer waters from the deep, accelerating the melting of the Antarctic Ice Sheet and raising global sea levels. It could also disrupt nutrient distribution, impacting phytoplankton growth—the foundation of the ocean food chain. Professor Kate Hendry of BAS puts it bluntly: “Antarctica’s mysteries are shaping our world. From rising seas to shifting weather, these processes are knocking on our doorsteps.”
A pressing question remains: Will a warming climate increase the frequency and intensity of these calving and tsunami events? Answering this could refine our climate models and predictions. The POLOMINTS project, a collaboration involving institutions from the UK, USA, and Poland, is at the forefront of this research, funded by the Natural Environment Research Council.
But what do you think? Could these underwater tsunamis be a missing piece in the climate puzzle, or are we overestimating their impact? Share your thoughts below—let’s spark a conversation about Antarctica’s hidden forces and their global implications.
