The Grand Canyon in Arizona is the world’s most recognizable gorge, a chasm that serves as the standard for geological immensity. However, the question of whether a larger canyon exists depends entirely on the criteria used for comparison. The term “bigger” is an ambiguous one in geology, as no single canyon holds all the records for size. To find a true rival to the Grand Canyon’s scale, one must look beyond its borders and consider formations that excel in specific dimensions, such as extreme depth, total length, or sheer volume. The answer shifts dramatically when the comparison moves from the familiar canyons carved by rivers to those hidden beneath ice or even located on another planet.
How Do We Define “Bigger”?
Geologists typically rely on three primary metrics to measure a canyon’s scale: depth, length, and volume. Depth is the vertical distance from the rim to the floor, while length is the total distance the chasm covers from end to end. Volume, which represents the total amount of rock and sediment excavated, offers the most comprehensive measure of overall size. The Grand Canyon’s massive scale is due to its impressive combination of all three dimensions, stretching approximately 277 miles long and plunging over a mile deep (about 6,000 feet) at its maximum depth. Its width varies significantly, reaching up to 18 miles across at its widest points.
Earth’s Deepest and Longest Rivals
Several river-carved chasms on Earth exceed the Grand Canyon in specific measurements, particularly depth and length. The Yarlung Tsangpo Grand Canyon, located in the Himalayas in Tibet, is widely regarded as the deepest terrestrial canyon in the world. This gorge, carved by the Yarlung Tsangpo River, features a maximum vertical drop of over 19,700 feet, which is more than three times the depth of the Grand Canyon. The Yarlung Tsangpo Canyon is also longer, extending for approximately 314 miles.
Other contenders gain recognition for their extreme depth, a characteristic often linked to powerful tectonic forces pushing up mountainsides faster than rivers can cut through them. For example, the Colca Canyon in southern Peru reaches depths of up to 10,700 to 11,155 feet, making it nearly twice as deep as the Grand Canyon. However, its length is significantly shorter, extending only about 60 miles. These contrasts highlight different geologic processes, with the Tibetan and Peruvian gorges owing their extreme depth to the intense uplift of surrounding mountain ranges.
Canyons of Massive Volume and Unique Formation
When the definition of “bigger” shifts to total volume or length, a different set of colossal formations emerges, many of which were not carved by traditional fluvial erosion. The Greenland Grand Canyon, or Mega-Canyon, is a prime example of a non-traditional formation that surpasses the Grand Canyon in length. Discovered beneath the massive Greenland ice sheet, this ancient river valley is at least 466 miles long, making it the longest canyon on Earth. Although its maximum depth is a shallower 2,600 feet, its immense length and significant width contribute to an enormous overall volume.
Another contender for the largest gorge by volume is the Zhemchug Canyon, a massive submarine formation located in the Bering Sea. This submerged chasm is considered the largest submarine canyon in the world, with an excavated volume estimated at 5,800 cubic kilometers. It boasts a vertical relief of 8,530 feet, making it significantly deeper than the Grand Canyon, but its formation is attributed to powerful underwater sediment flows and mass wasting, rather than the river erosion that shaped most land-based canyons.
The Largest Canyon Known in the Solar System
The search for a truly larger canyon must extend beyond Earth’s atmosphere to the planet Mars, home to the Valles Marineris. This immense geological feature dwarfs all terrestrial canyons and is the largest known chasm in the solar system. Valles Marineris stretches for over 2,500 miles across the Martian equator, a distance roughly equivalent to the entire width of the United States. In terms of depth, it plunges up to 4 to 5 miles, or 7 to 8 kilometers, significantly deeper than any canyon on Earth.
It is almost ten times longer and five times deeper than the Grand Canyon. Unlike the Grand Canyon, which was carved by the persistent flow of the Colorado River, the Martian mega-canyon is believed to have formed primarily through tectonic fracturing. This process involved the stretching and cracking of the planet’s crust billions of years ago, a geological event linked to the rise of the nearby Tharsis volcanic plateau. The Valles Marineris places Earth’s greatest gorges into perspective.