Something strange hides beneath Antarctica’s ice. For centuries, scientists could only guess what lay under the frozen shelves that extend from the continent into the sea. Satellites captured images from above. Ice cores offered glimpses of history. But no one had ever truly seen what existed in those dark, freezing waters where ice meets ocean.

Until a submarine named Ran went looking.

What it found before vanishing forever has left researchers scrambling to rewrite their understanding of how glaciers melt. And the images it sent back reveal a world far stranger than anyone expected.

Into Waters No Human Could Survive

In early 2022, an international team of scientists arrived at the Dotson Ice Shelf in West Antarctica. Their mission was simple in concept but daunting in execution. They needed to send an unmanned vehicle beneath 350 meters of solid ice to map what no human eye had ever seen.

Ran, an autonomous underwater vehicle built to survive extreme conditions, was their only option. Equipped with advanced sonar, the submarine could create detailed maps of surfaces above it while swimming through near-freezing water in complete darkness.

For 27 days, Ran traveled back and forth beneath the glacier. It covered more than 1,000 kilometers, venturing 17 kilometers into the ice cavity. Each mission lasted over 24 hours. During that time, the vehicle had no contact with the researchers waiting nervously above. It followed pre-programmed routes, trusting its navigation systems to guide it back to open water.

Lead researcher Anna Wåhlin, Professor of Oceanography at the University of Gothenburg, described the experience of reviewing Ran’s data for the first time. “It’s a bit like seeing the back of the moon,” she said.

A Landscape Carved by Invisible Forces

Scientists expected to find a relatively smooth ice base, perhaps with some channels carved by flowing water. What Ran revealed instead looked almost alien.

Peaks and valleys stretched across the underside of the glacier. Flat plateaus gave way to steep walls dropping several meters. Swirling patterns curved through the ice like frozen whirlpools. And scattered throughout certain regions, strange teardrop-shaped divots appeared in clusters, some stretching up to 300 meters long.

Nobody had ever seen anything like it. In other areas, formations resembling dunes ran along the ice base, reaching lengths of 400 meters. Full-thickness fractures, cracks that extended from the bottom of the ice all the way to the surface, showed signs of erosion that had occurred over decades. Some of these fractures had been widening since the 1990s, slowly eaten away by forces scientists were only beginning to understand.

When the research team studied the teardrop shapes more closely, they noticed something peculiar. Every single one of them curved in the same direction. They were not random formations. Something had carved them with precision and consistency.

Earth Itself Shapes What Lies Below

After months of analysis, researchers developed a theory to explain the mysterious teardrops. Our planet’s rotation was responsible.

As Earth spins, it creates a phenomenon called the Coriolis force. Moving water does not travel in straight lines because of this effect. In the Southern Hemisphere, currents veer to the left of their original direction. Near the ice base, where flowing water meets the frozen ceiling above, this veering creates a spiral pattern.

When a disturbance occurs at the ice surface, perhaps a small crack or a rock melting out of the glacier, it can trigger a turbulent plume of water. Instead of spreading evenly in all directions, that plume curves according to the Coriolis force. Over time, repeated melting carves the ice into asymmetric teardrop shapes.

Older teardrops have longer tails that run more parallel to the main water flow. Younger ones show sharper curves. Scientists believe this pattern confirms their theory about how Earth’s spin slowly sculpts the underside of Antarctic ice.

Western portions of the ice shelf told a different story. Fast-moving currents in those regions had eroded the ice into smooth surfaces. Melt rates there reached 15 meters per year, far higher than the slower eastern sections. Strong underwater currents acted like sandpaper, wearing away any formations before they could fully develop.

Racing Against Rising Seas

Dotson Ice Shelf sits beside Thwaites Glacier, sometimes called the Doomsday Glacier because of the catastrophic sea level rise its collapse could trigger. West Antarctica holds enough ice to raise global oceans by several meters. Understanding how these glaciers melt is not merely academic curiosity. Coastal cities worldwide depend on accurate predictions.

Before Ran’s mission, climate models made assumptions about ice shelf melting that now appear far too simple. Scientists believed melting occurred in relatively predictable patterns based on water temperature and flow speed. Ran’s maps proved that reality is far messier.

Fractures channel warm water deep into the ice. Plateaus and terraces create zones where melting slows dramatically. Swirling patterns suggest that past melting events can steer future currents, creating feedback loops that accelerate or slow the process in ways models never anticipated.

Researchers now face years of work analyzing Ran’s data and updating their predictions. Better models could mean better preparation for coastal communities facing rising waters in the coming decades.

Lost to the Ice

In January 2024, the team returned with Ran to repeat their surveys. They hoped to document how the ice shelf had changed in two years, providing even more valuable data for climate scientists.

After one successful dive, Ran descended again beneath the ice. It never came back.

Search teams deployed acoustic equipment, drones, and helicopters. Nothing worked. Wåhlin described the effort with grim honesty. “It’s a bit like looking for a needle in a haystack, but without even knowing where the haystack is.” Anna Wåhlin said.

Ran’s batteries have long since died. Whatever happened beneath the ice remains a mystery. Scientists suspect the vehicle encountered an unexpected obstacle, perhaps a shift in the ice or an uncharted formation, and could not escape.

Rather than mourn the loss, the team views it as a fitting conclusion for an explorer. Ran spent its final moments doing what it was built to do, pushing into places no machine had gone before. Gathering dust in a storage facility would have been a far sadder fate. Plans are already underway to build a replacement and continue the research Ran started.

What the Ice Teaches Us About Ourselves

Few places on Earth remain unseen. Most mountains have been climbed. Most oceans have been charted. Yet beneath Antarctic ice shelves, entire worlds exist that human eyes have never witnessed. Ran’s journey into that cold darkness mirrors something deep within us, a drive to push past safe boundaries and peer into spaces we were never meant to see.

Exploration demands sacrifice. Equipment fails. Missions end before their time. But each kilometer Ran traveled produced data that will outlive its metal shell. Scientists will study these maps for decades, building better predictions, refining models, and preparing communities for waters that may rise.

Perhaps what matters most is the willingness to send something precious into the unknown, knowing it might not return. When we look at these strange formations beneath Antarctic ice, we see more than geology. We see evidence that our planet still holds secrets worth chasing. And we see a reminder that understanding our world, especially its most fragile parts, remains among the most meaningful work we can do.

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