Have you ever wondered what keeps you awake at night about our planet's future? For climate scientists, there's one name that sends chills down their spines more than any other: Thwaites. Welcome to FreeAstroScience, where we break down complex scientific principles into simple terms you can actually understand. Today, we're taking you on a journey to one of the most remote—and most terrifying—places on Earth. Grab a coffee, settle in, and read to the end. What we've learned recently about this glacier might change how you see our planet's future.
What Makes the Thwaites Glacier So Dangerous?
Let's start with the basics. The Thwaites Glacier sits in West Antarctica. It's massive—about 120 kilometers wide, up to 1,200 meters deep, and covers roughly 192,000 square kilometers. That's almost the size of Great Britain. Scientists call it the "Doomsday Glacier" for a very good reason: if it collapses entirely, global sea levels could rise by more than 1 meter.
But here's what makes Thwaites particularly scary. It's not just big. It's unstable.
The glacier contains enough ice to raise global sea levels by approximately 65 centimeters on its own. And much of it rests on a bed that slopes downward toward the interior of the continent—a configuration that makes it prone to what scientists call "marine ice sheet instability" . Once retreat begins, it can become self-reinforcing and potentially irreversible.
We're watching that retreat happen right now.
How Is the Glacier Breaking Apart?
A team led by researchers at the University of Manitoba has just published groundbreaking findings in the Journal of Geophysical Research: Earth Surface . They analyzed twenty years of satellite data, GPS measurements, and ice-flow observations from 2002 to 2022. What they found is both fascinating and alarming.
The Two-Stage Fracture Process
The Thwaites Eastern Ice Shelf—a floating extension of the glacier anchored to an offshore ridge—is cracking in a predictable pattern :
Stage One: Long fractures form parallel to the direction of ice flow. These shear fractures spread across the width of the shelf, gradually disconnecting it from its anchor point.
Stage Two: Once those long fractures weaken the structure, smaller tensile cracks appear perpendicular to flow. These fractures multiply rapidly.
Think of it like this: imagine a piece of tape stuck to a surface. First, you peel it from one edge (the long shear fractures). Then, as tension builds, small tears appear across the tape's width (tensile fractures). Eventually, it gives way entirely.
| Measurement | 2002 | 2021 | Change |
|---|---|---|---|
| Total Fracture Length | 165.2 ± 6.6 km | 335.5 ± 13.4 km | +103% |
| Average Fracture Length | 3.2 ± 0.8 km | 1.5 ± 0.2 km | -53% |
| Internal Mélange Area (2022) | — | 16.5 ± 2.5 km² | Significant increase |
The declining average fracture length tells us something important: smaller fractures are multiplying faster than longer ones are forming . The glacier isn't just cracking—it's fragmenting.
What's the Role of the Pinning Point?
Here's where things get really interesting—and where I had my "aha" moment while reading this research.
The Thwaites Eastern Ice Shelf is anchored to an underwater ridge called a "pinning point." For years, this pinning point acted like a doorstop, slowing the glacier's slide into the ocean. The ice compressed against it, and that compression provided stability .
But something changed.
As the ice shelf accelerated and thinned, compression turned into shearing. Instead of pressing against the pinning point, the ice began grinding past it. And shearing creates fractures .
The researchers describe this beautifully: "the 'compression against the pinning point,' once the major stabilizing force, has gradually transformed into 'shearing against the pinning point,' a source of fracture and a major destabilizing driver" .
The very feature that once protected the glacier is now helping to destroy it.
Why Are Underwater Eddies Making Everything Worse?
Deep beneath the ocean's surface, far from where we can easily observe them, swirling currents one to ten kilometers wide are forming constantly . A recent study published in Nature Geoscience, led by Mattia Poinelli at the University of California, revealed that these underwater eddies carry warm deep water directly beneath the glacier's floating ice shelves .
These pulses of warm water often last just days. Yet their impact is enormous.
The simulations show that eddies are responsible for approximately one-fifth of Thwaites Glacier's annual melt loss . One-fifth! From currents we barely knew existed until recently.
But it gets worse. The researchers identified a feedback loop:
- Eddies deliver warm water beneath the ice
- The ice melts, releasing fresh meltwater
- Meltwater changes the ocean's layering (stratification)
- Altered stratification favors the formation of more eddies
- More eddies deliver more warm water
- The cycle accelerates
We're not just watching a glacier melt. We're watching a self-reinforcing system that speeds up over time.
The Four Phases of Collapse
The Manitoba research team divided Thwaites' recent history into four distinct phases . Understanding them helps us see where we are now—and where we might be heading.
Phase 1 (2002-2006): The Drag Effect
The Thwaites Western Ice Tongue—a neighboring ice mass—flowed about four times faster than the Eastern Ice Shelf. A robust shear margin connected them. As the Western Tongue accelerated, it dragged the Eastern Shelf forward . Fractures began forming near the pinning point, but the system remained relatively stable.
Phase 2 (2007-2011): The Breakup
Around 2007-2009, the shear margin between the two ice masses disintegrated. Once disconnected from its faster neighbor, the Eastern Ice Shelf slowed down . But damage had already been done. Existing fractures began propagating eastward across the shelf's width.
Phase 3 (2012-2016): Quiet Acceleration
Flow speed stayed relatively constant, but the long shear fractures kept spreading. Scientists noticed high strain-rate bands in satellite data—zones of structural weakness—months before visible cracks appeared . The shelf was weakening from within.
Phase 4 (2017-2022): The Current Crisis
This is where we are now. The long fractures have nearly severed the shelf's connection to its pinning point. Small tensile fractures are multiplying rapidly. The mid-shelf ice has shifted from a compressive regime (being pushed against the pinning point) to an extensional regime (being stretched apart) .
The ice upstream is now accelerating, flowing faster toward the sea with each passing month.
What Happens If Thwaites Collapses?
Let's be honest with each other. Scientists don't know exactly when—or even if—Thwaites will experience a catastrophic collapse. But they do know what's at stake.
| Scenario | Sea Level Rise |
|---|---|
| Thwaites Glacier alone (complete melt) | ~65 cm |
| Thwaites + destabilized neighboring glaciers | > 1 meter |
| Current projected annual contribution | 0.21–0.29 mm/year |
| Projected grounding line retreat rate | ~1 km/year |
*Data sources: *
And Thwaites isn't alone. The same mechanisms—warm water intrusion, pinning point failure, feedback loops—could affect other Antarctic ice shelves . If multiple systems destabilize simultaneously, we're looking at a very different planet.
Coastal cities would flood. Hundreds of millions of people would need to relocate. Ocean circulation patterns would shift dramatically, affecting weather systems worldwide .
What Can We Still Learn?
Here's something that surprised me: despite all this research, scientists still can't directly observe what's happening beneath the ice. The space between the glacier's base and the seafloor is inaccessible to research vessels . Most of what we know comes from models, satellite imagery, and a handful of probe measurements.
Some observations match the models. Others don't. Uncertainty remains.
But here's what is clear: we're running out of time to understand these systems before they change irreversibly.
The researchers acknowledge that their findings are "consistent with the initiation phase of a self-reinforcing feedback mechanism" . If that feedback fully activates, the Eastern Ice Shelf's disintegration will accelerate beyond what we're seeing today.
What Does This Mean for Us?
If you've read this far, you might feel a bit overwhelmed. That's okay. We feel it too.
But knowledge isn't just about facing uncomfortable truths. It's about understanding our world well enough to act wisely. The researchers studying Thwaites aren't doom-mongers—they're problem-solvers. Every data point, every fracture mapped, every eddy tracked brings us closer to accurate predictions. And accurate predictions help communities prepare.
At FreeAstroScience, we believe the sleep of reason breeds monsters. Staying informed, staying curious, keeping your mind active—these aren't just academic exercises. They're acts of responsibility.
Final Thoughts: The Glacier That Watches Back
We often think of glaciers as passive—ancient ice formations that simply exist. Thwaites reminds us that glaciers are dynamic systems, responding to forces both ancient and terrifyingly modern.
The warm eddies churning beneath the ice. The fractures spreading across the shelf's surface. The pinning point that once stabilized and now destabilizes. These aren't abstract processes. They're happening right now, reshaping one of the largest glaciers on Earth.
Will Thwaites collapse in our lifetimes? Possibly. Will its neighbors follow? We don't know yet. But we're watching more closely than ever before, and that watching matters.
Come back to FreeAstroScience.com to keep expanding your understanding of our changing planet. Because in times of uncertainty, knowledge is the one thing that can never be taken from you.
Sources
Kubny, H. (2025). How Underwater Eddies Threaten Antarctic Glaciers. Polar Journal. Based on research by Poinelli, M. et al., published in Nature Geoscience. https://www.nature.com/articles/s41561-025-01860-8
Polastro, I. (2025, December 11). Il Ghiacciaio dell'Apocalisse in Antartide è sempre più instabile: le conseguenze di un possibile collasso. Geopop. https://www.geopop.it/il-ghiacciaio-dellapocalisse-in-antartide-e-sempre-piu-instabile-le-conseguenze-di-un-possibile-collasso/
Banerjee, D., Lilien, D. A., Truffer, M., Luckman, A., Wild, C. T., Pettit, E. C., Scambos, T. A., Muto, A., & Alley, K. E. (2025). Evolution of Shear-Zone Fractures Presages the Disintegration of Thwaites Eastern Ice Shelf. Journal of Geophysical Research: Earth Surface, 130, e2025JF008352. https://doi.org/10.1029/2025JF008352
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