What Is a Pingo and Why Does Canada Have the Most on Earth?

What Is a Pingo?

A pingo is a dome-shaped hill with a solid ice core at its heart, slowly pushed upward from below by freezing groundwater trapped beneath the Arctic tundra. Canada’s Tuktoyaktuk Peninsula in the Northwest Territories is home to roughly 1,350 of them — the densest concentration anywhere on Earth.

How Does a Pingo Form?

The process begins when a shallow Arctic lake drains. While that lake existed, its liquid water acted as a thermal blanket, keeping the ground directly beneath it unfrozen even in the deep cold. Once the lake disappears, the surrounding permafrost — which had been closing in from all sides — suddenly has nowhere left to go but inward and upward.

The waterlogged sediment beneath the former lakebed freezes and expands. The remaining liquid is squeezed upward, where it freezes too, building a growing mass of buried ice. That ice core then physically domes the soil and rock above it into a hill that can rise for centuries. The word pingo comes from an Inuit language and means simply “small hill” — a modest name for something that can grow taller than a fifteen-story building.

How Tall Can Pingos Get?

The tallest pingo in Canada — and one of the largest in the world — is Ibyuk Pingo, located near the town of Tuktoyaktuk in the Northwest Territories. It stands 161 feet (49 meters) high and stretches nearly 984 feet (300 meters) across its base. Ibyuk began rising around 700 CE, making it approximately 1,300 years old. Despite its age, it has not stopped growing — scientists estimate it still rises close to an inch (2.5 cm) per year, driven by the expanding ice core beneath it.

What Happens When a Pingo Collapses?

Pingos are not permanent. If the ice core warms and melts, the hill loses its internal support and collapses inward. The result is a circular, water-filled depression called a pingo scar or pingo crater lake. Over time, the crater’s raised rim — called a rampart — erodes inward. The water may drain, and wetland plants such as sedges and willows begin colonizing the floor. Eventually, what was once a centuries-old hill becomes a marsh, meadow, or sediment-filled depression — a quiet reversal of everything the ice built.

Are There Pingos on Mars?

Scientists studying planetary geology have identified dome-shaped mounds on Mars that closely resemble terrestrial pingos. Because Mars has documented subsurface ice, researchers consider Earth pingos direct analogues for these Martian structures — meaning the same ice-expansion process that built Ibyuk may be actively reshaping another planet’s surface right now. The Tuktoyaktuk pingos are therefore not just a Canadian geological curiosity; they are a field laboratory for understanding ice dynamics across the solar system.

Are Pingos at Risk?

Yes. Accelerating permafrost thaw driven by climate change now threatens to destabilize pingos across the Arctic, including Ibyuk itself. As regional temperatures rise, the permafrost that sustains the freezing pressure inside each pingo becomes less stable. Structures that took hundreds or thousands of years to build could collapse within decades to centuries. Ibyuk — which began its rise around 700 CE and is still growing — now faces the real possibility that the ice which built it will become the thing that undoes it.

Why Tuktoyaktuk?

The Tuktoyaktuk Peninsula’s geography makes it uniquely suited to pingo formation. Its flat, low-lying tundra landscape is riddled with shallow lakes — exactly the kind that drain and trigger the groundwater-freezing cycle. Nowhere else on Earth combines the right permafrost depth, lake density, and drainage patterns to produce pingos at this scale. The region’s 1,350 pingos represent a landform record unmatched on the planet.