The highest mountains in the world are the massive ranges that form the Himalayas, between the Tibetan plateau and the Indian subcontinent. Here, the great land mass of India slowly slams into the mass of Asia in a collision that began eons ago, creasing and folding the living rock into the mighty Himalayan, Karakoram, and Hindu Kush mountain chains that dominate the world.
Mount Everest, 8848 meters high, stands on this great plateau. Its neighbor K2, at 8611 meters, is the world’s second highest mountain. The other 98 of the 100 highest mountains in the world all stand on this same plateau. No other mountain ranges on earth come close to rising as high.
Yet, looked at another way, Mauna Kea is still taller than Mount Everest. An ancient shield volcano that is now dormant, Mauna Kea is one of five volcanoes that form the Big Island of Hawaii. Above tropical Hawaii, snow falls atop Mauna Kea. Pu'u Wekiu, one of the cinder cones on the mountain's summit plateau, is the highest point in the state, at 4205 meters (13796 ft.) above sea level. What is more, measured from its sea floor foundation, this volcano is the tallest mountain in the world, at 10,200 meters (33,500 feet). Everest doesn't even come close. Mauna Kea is sinking now, geologists believe, as it pushes down the ocean floor with crushing weight.
Other mountains can be called the tallest too. Another way to measure mountains is by surveying their height above the surrounding base. By this standard, Everest, which starts at the great height of the Tibetan Plateau, is not so high. Mountains that stand higher above their base include Mount McKinley, Mount Kilimanjaro, and Nanga Parbat.
The Himalayas come to their western end at Nanga Parbat, which rises abruptly above the surrounding land in Pakistan. On the south flank of the mountain, the Rupal Face rises 4600 meters above the surrounding base in one breathtaking sweep, and on the north the Rakhiot flank rises 7000 meters (22,966 feet) from the Indus River Valley to the summit.
Mount McKinley, originally called Denali, is the highest peak in North America, at 20,320 feet (6194 meters). The base of Mount McKinley sits at about 2,000 feet, giving it a rise of about 18,000 feet (5,500 meters). The rise above base of Mount Everest, measured the same way, is about 12,000 feet (3,700 meters).
Kilimanjaro is the highest peak in Africa at a height of 5895 meters (19,340 feet), and rises 4600 meters (15,100 feet) from its base. Its highest point is Uhuru peak, on Kibo crater. Kilimanjaro is a stratovolcano, built up over the centuries out of layers of lava and tephra (solid material thrown out of the volcano).
Finally, if height is considered to be distance away from the center of the earth, then a comparatively little-known inactive volcano in the Andes is the highest mountain in the world. Chimborazo (6268 meters or about 20,700 feet) is the highest peak in Ecuador, and is located right on the equator. Since the earth is not round, but bulges at the equator, Chimborazo reaches the greatest distance from the earth's core of any mountain.
By ordinary standards Chimborazo is not even the highest mountain in the Andes however. That honor is held by magnificent Aconcagua, called the highest peak in the Western Hemisphere. Ranked by distance from the center of the earth though, several other Andean peaks, as well as Kilimanjaro, also precede Mount Everest.
Certainly, Mount Everest will continue to be considered the highest mountain in the world. However, geographers and logicians will continue to point out that there are many ways to measure, and many ways to define, height. Therefore, many mountains qualify as the tallest in the world.