When going about the task of determining exactly which of the planet’s numerous chasms actually qualify as the 10 biggest, it really comes down to what criteria you choose to apply. Some are accorded size by the measurement from the rim to the base. For others, it’s about sheer area occupied across the landscape. In any case, each of these canyons possesses qualities that merit ranking among the largest on Earth.
If you’re looking to find the truly deepest canyon worldwide, then the clear winner is the Mariana Trench, in the western Pacific Ocean. At over 36,000 feet deep, it dwarfs all other contenders. Unlike its land-bound contemporaries, which were shaped primarily by erosion, it was formed by one tectonic plate pushing up against another. The next best examples of exceptional depth are found in a pair of canyons in Peru. The first, Cotahusai Canyon, boasts a depth of 11,598 feet. The other, Colca Canyon, plummets even further, to a distance of 13,650 feet.
Our next canyon stop takes us to Nepal, and the Kali Gandaki Gorge. The actual depth remains in debate, since some judge it from the level of its rim, while others claim it begins upon the summit of the two enormous Himalayan peaks rising on either side, which would make it over 22,000 feet deep. Moving on to Tibet, the sprawling Yarlung Tsangpo Grand Canyon descends to a depth of nearly 19,714 feet from its rim, while extending over 150 miles of terrain. The terms gorge and canyon generally refer to the same basic landforms -- canyon is used primarily in the U.S., and gorge is more of a European term.
At 4,265 feet, the Tara River Gorge, located in Montenegro, has the distinction of being the deepest river gorge in all of Europe. Its twisting path cuts across 50 miles of landscape. The immense Copper Canyon in Chihuahua, Mexico, is not one but a combination of six different canyons. At the bottom of its 6,164-foot depth, its rushing waters wind their way towards the Sea of Cortez. The Colorado River cut a complex network of channels through the Arizona landscape to form the capacious Grand Canyon, expanding over an area of 277 miles. From its North Rim, it descends 6,000 feet.
Africa also has its share of magnificent canyons and waterways. The Fish River Canyon in Namibia is the largest, extending over the terrain for a hundred miles. Although not particularly deep at 1,800 feet, there are portions along its path where it can span up to 17 miles across. In South Africa, the Blyde River Canyon is known as one of the most verdant areas on the continent, its lush banks dropping off to an impressive depth of 4,500 feet.
