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Where and what is Mount Everest? -

Mount Everest is the world's tallest mountain and is located in the Himalayas, a mountain range that stretches across five countries: Nepal, Tibet, Bhutan, India, and Pakistan. Everest itself straddles the border between Nepal and Tibet. 

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When were the Himalayas formed? -

The Himalayas were formed around 50 to 60 million years ago during the Cenozoic Era. Their formation began when the Indian tectonic plate collided with the Eurasian plate, causing the Earth's crust to buckle and fold, leading to the creation of the mountain range.

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The process is ongoing -

The Indian tectonic plate continues to push into the Eurasian plate at a rate of approximately 2 inches (5 centimeters) per year, contributing to the gradual rise of the Himalayas. 

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An additional boost -

Experts now suggest that Everest has been experiencing an additional boost in height due to erosion caused by the neighboring Arun and Kosi rivers.

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The evolution of river networks -

Scientists suggest that around 89,000 years ago, the upper section of the Arun River, located north of Everest and once flowing eastward across the Tibetan plateau, merged with its lower section due to the lower reach eroding northward.

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The Kosi River system -

The entire length of the Arun River became part of the Kosi River system, resulting in an increase in river erosion near Everest, and the formation of the Arun River gorge.

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Erosion -

The newly formed river system eroded vast amounts of rock and soil from the base of the Himalayas, which lightened the load on the Earth's crust below the mountain range, triggering a process known as isostatic rebound.

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Pushing Mount Everest higher -

The Earth's crust, which floats on the mantle, rose in response to the reduced weight, pushing Everest and the surrounding land higher. This accounts for as much as half of the mountain’s annual growth or uplift rate.

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Earthquakes and mountain growth -

When the land compresses, pressure accumulates until it reaches a breaking point, causing blocks of earth to abruptly shift and shake the ground in the sudden jolt of an earthquake. Depending on how and where the ground shifts, tremors can cause Everest to either grow or shrink in small amounts.

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How much could Everest grow per year? -

Experts say the erosion and crust movement is causing Everest to grow 0.16 to 0.53 millimeters a year. They report that the mountain has gained as much as 2 millimeters annually in recent years.

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A surprising dimension to the study of mountain formation -

The river capture and erosion-related isostatic rebound playing a role in Everest's elevation is surprising to scientists, changing the study of mountain formation, which is traditionally explained by tectonic activity. 

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The Earth as an interconnected system -

The recent findings also emphasize the importance of perceiving the Earth as an interconnected system, where a change in one area can have a surprising and significant impact somewhere else.

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The Alps -

The Alps, stretching from Italy through France, Switzerland, Liechtenstein, Germany, Austria, and into Slovenia, are also experiencing growth, although at a different rate compared to Mount Everest.

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How are the Alps growing? -

The Alps are growing due to the ongoing collision of the African and Eurasian tectonic plates, which causes uplift. This activity results in a rise of several millimeters per year. While erosion also shapes the landscape, the tectonic forces continue to contribute to the Alps' growth over time.

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Do mountains grow forever? -

When two tectonic plates collide and continue to push against each other, a mountain will keep growing until it becomes too heavy, which may contribute to the cessation of upward growth.

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Do mountains grow forever? -

Mountains don't only form via tectonic plates colliding. Volcanic mountains, like those of the Hawaiian Islands, are formed from molten rock that erupts through the planet's crust and begins to pile up. They too can become too heavy and succumb to gravity.

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Mountains and less gravity -

If Earth had less gravity, the mountains would grow higher. This is what happened on Mars, where Olympus Mons, the tallest known mountain in the solar system, extends 82,000 feet (25,000 meters) high.

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Mountains and less gravity -

NASA suggests that Mars' low gravity and high eruption rates allowed mountain-building lava flows to persist far longer than on Earth. Unlike Earth’s tectonic plates that create multiple volcanoes, Mars' stationary crust causes lava to accumulate into a single, massive volcano.

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Rivers as a limiting factor for mountain growth -

Rivers cut into the mountain's edges and erode its materials, forming deep crevices near the base. However, as the rivers continue to erode, the channels can become excessively steep.

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Landslides -

If the channels become too steep, it can trigger landslides that carry material away from the mountain and limit its growth. This process not only removes sediment but can also destabilize the mountain's structure, potentially leading to further erosion and preventing the accumulation of new material needed for upward growth.

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Underwater mountains -

Underwater mountains are also affected by gravity and landslides, but they can grow taller than land-based mountains because the density of water supports them against gravitational forces.

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Other contenders for the world's tallest mountain -

Mauna Kea, an inactive volcano in Hawaii, is the world's tallest mountain when measured from its base in the Pacific Ocean to its summit, with a total height of 33,500 feet (10,210 meters).

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Mauna Kea vs. Everest -

Mauna Kea's base is 19,700 feet (6,000 meters) below sea level and its peak is at 13,796 feet (4,205 meters) above sea level. When measured from sea level, Mount Everest is over two times taller than Mauna Kea.

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Lhotse -

Neighboring Lhotse, the world's fourth highest peak, is experiencing an uplift rate similar to Everest. However, no precise growth figures for Lhotse alone are widely reported at the moment.

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Nanga Parbat -

Nanga Parbat is the ninth-highest mountain in the world, standing at 26,660 feet (8,126 meters). It is located in the western Himalayas, in Pakistan's Gilgit-Baltistan region. 

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Will Nanga Parbat grow taller than Mount Everest? -

Nanga Parbat is said to be growing at a rate of 7mm per year. In 241,000 years it could overtake Everest to be the tallest mountain on Earth, as long as rates of erosion don't change.

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The future of the Himalayas -

In the distant future, a new tectonic boundary will form, and the forces driving the uplift of the Himalayas will cease. Over time, the range will collapse and gradually erode, eventually resembling the present-day Appalachians in North America, which were once an active mountain belt around 325 to 260 million years ago.

Sources: (Live Science) (The Guardian) (CNN) (National Geographic)

See also: Mountains that cross international borders

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