Mount Everest in the Himalayas is the world’s highest point, with an altitude of 29,032 feet above sea level. That’s like 20 Empire State Buildings stacked on top of one another, including their spires and antennae. Mount Everest is so tall that its summit can poke into the South Asian jet stream, whose winds and flying snow can cancel climbers’ ascents. But, perhaps surprisingly, the height of Mount Everest is changing. Is its place in the record books at risk?
When surveyors first measured Mount Everest in the 1850s, its elevation was calculated to 29,002 feet [PDF]; it was re-measured in 1955 at 29,029 feet, and the most recent survey in 2020 came up with 29,032 feet. Like other mountains around the world, Everest’s elevation shifts due to plate tectonics and earthquakes. And there are long-standing arguments over snow height versus rock height. But even if it gains or loses a yard or two, Everest is not in danger of relinquishing its claim to fame any time soon. The second highest point on Earth, the summit of K2 in the Karakoram range is only 28,251 feet above sea level.
That’s not to say that Mount Everest is the tallest mountain on Earth. That honor belongs to Mauna Kea in Hawaii, which is a colossal dormant volcano. It rises 13,803 feet above sea level which, you may be thinking, is less than half the elevation of Mount Everest. But 60 percent of Mauna Kea is underwater. When factoring in its height from the seabed to the ocean’s surface, which is about 19,700 feet, the volcano’s total height equals 33,503 feet. That’s more than 6.3 miles from bottom to top. In fact, the largest mountains on the planet are the shield volcanoes that created the islands of Hawaii.
Mount Everest and Mauna Kea are just the tip of the geographical iceberg when it comes to Earth’s geographical extremes. In the latest episode of The List Show, Mental Floss editor-in-chief Erin McCarthy discusses some impressive geographical superlatives, from the planet’s deepest caves to its tallest peaks to its blusteriest winds.
The deepest cave on Earth, for example, is Veryovkina in Abkhazia, Georgia. In 2018, after numerous expeditions over several decades, a team of spelunkers rappelled 1.3 miles down to the bottom. Veryovkina is in what is known as a karst terrain, a type of formation mostly made of limestone that is easily worn away by water. The hydrological activity leaves behind sinkholes, springs, and long, twisting caves.
And the world’s deepest lake is so isolated that a unique ecosystem and animal species have evolved in and around it over the past few million years. Lake Baikal in Siberia lies on a continental rift—a place where two tectonic plates meet. Over time, the plates have pulled away from each other and water has filled the gap, forming the world’s deepest lake at approximately 5500 feet deep. It’s also often called the world’s oldest lake at about 25 million years old, and holds 20 percent of all the fresh surface water on Earth. Baikal seals—the only seal species to live exclusively in fresh water—swim in its depths along with an exceptional number of plants and animals found nowhere else. Lake Baikal is pretty great—even greater than the Great Lakes, whose total water volume could fit inside it.