What Is the Largest Submarine Canyon on Earth?

The Largest Submarine Canyon on Earth

The Zhemchug Canyon, located in the Bering Sea, is the largest submarine canyon on Earth — plunging approximately 2,600 meters deep and covering an area greater than the Grand Canyon in both depth and volume.

Where Is Zhemchug Canyon?

Zhemchug Canyon sits beneath the Bering Sea, off the western coast of Alaska, carved into the continental shelf between Alaska and Russia. It is remote, frigid, and almost entirely invisible to the world above — yet it is one of the most consequential geological features on the planet. Unlike the Grand Canyon, which you can hike, photograph, and stand at the rim of, Zhemchug exists in total darkness beneath hundreds of meters of cold Arctic water.

How Deep Is Zhemchug Canyon Compared to the Grand Canyon?

The Grand Canyon’s most extreme rim-to-floor drop reaches roughly 1,800 meters — already one of the most dramatic vertical plunges on dry land. Zhemchug Canyon descends to approximately 2,600 meters at its deepest point. That difference is not trivial. Stack five Empire State Buildings on top of each other and you still would not reach the canyon’s floor from its rim. In terms of cross-sectional area and overall volume, Zhemchug dwarfs anything comparable on the surface of the Earth.

How Was Zhemchug Canyon Formed?

Submarine canyons like Zhemchug are typically carved over millions of years by a combination of erosion from ancient rivers, turbidity currents — underwater avalanches of sediment — and the slow reshaping of continental shelves. During ice ages, when sea levels dropped dramatically, rivers that once flowed across what is now seafloor cut deep channels into the continental shelf. As sea levels rose again, these canyons were submerged, preserved in the dark beneath the ocean.

Why Is Zhemchug Canyon So Important to the Food Supply?

This underwater abyss is quietly feeding millions of people. The canyon functions as a natural upwelling funnel — its steep walls and depth force cold, nutrient-rich water from the deep ocean up toward the surface. This process triggers massive blooms of phytoplankton, the foundation of the marine food chain, some of which are large enough to be photographed from space by satellites. Those blooms support enormous populations of fish, crab, pollock, and other commercially harvested species. The Bering Sea as a whole produces roughly 50 percent of all commercial seafood caught in the United States every year, and Zhemchug Canyon is one of the engines driving that productivity.

Why Have Most People Never Heard of It?

Zhemchug Canyon suffers from a simple problem: it is invisible. There is no overlook, no hiking trail, no tourist infrastructure. It does not appear in school geography lessons the way the Grand Canyon does. And yet, by nearly every metric of scale — depth, volume, ecological impact — it is more extreme than the geological landmarks that dominate popular imagination. The deep ocean remains one of the least explored environments on Earth, and Zhemchug is a perfect example of how much is hidden just beneath the surface of things most people never think to question.

The Deep Ocean Hides More Than We Know

Zhemchug Canyon is a reminder that Earth’s most extreme geography is not always the kind you can see. The ocean floor holds canyons deeper than mountains are tall, plains wider than continents, and ecosystems that feed the human world from total darkness. The Bering Sea, cold and storm-battered and largely ignored, quietly sustains half of American commercial seafood through geological processes that began millions of years ago and continue today.