Scientists think they have discovered why Mount Everest, known as Tibet’s Chomolangma and Nepal’s Sagarmatha, stands out from other mountains in the Himalayas.
A new model says an overlooked “piracy” force is at work on the world’s tallest mountain, which can reach up to 50 meters (about 160 feet) high. But it’s not like attacking ships on the high seas. The type that catches rivers.
Obviously, Everest’s record height of 8,849 meters would be nowhere to be found without the rupture of the plates. However, due to the uniformity of the geology along the fault, all peaks should be more or less the same height.
Most of the Himalayan mountains differ by less than 100 meters. Stretching 250 meters above any of its neighbors, this one is clearly hiding a secret.
Additionally, GPS data shows that Everest has grown several millimeters every year to this day, faster than the rate of uplift expected by tectonic plates.
There must be another force at work, and scientists at the China University of Geosciences and University College London think they have discovered it.
Their model suggests that the world’s highest peaks were raised higher than others by geological piracy. Piracy occurs when one river is “occupied” by a neighboring river. This changes the flow of sediment and reshapes the river and its tributaries into new patterns.
today, arun river It is a major tributary that cuts through the heart of the Himalayas through a deep and narrow valley, with a total length of 35 kilometers and a drop in elevation of 7 kilometers.
But when this river was formed long ago, there was no need for landslides or glaciers to help carve such a deep path through the northern slopes of Chomolungma. Vast amounts of water gave us all the power we needed.
According to the model, around 89,000 years ago, the Arun tributary began taking in more water from its parent, the Kosi River, and the sudden increase in water power could have easily incised the gorge.
Removal of large chunks of rock would have caused crust “floating” on top of the mantle to bounce back, causing “uplift of surrounding uncut surfaces, including mountain peaks.” I will write An international team led by Xu Han from China University of Geosciences.
Based on their models, the research team estimates that Chomolungma’s current height is between 15 and 50 meters, which may be due to river drainage piracy.
Compared to the Arun River, other rivers flowing through the Himalayas have a more consistent flow history, meaning that erosion at the foot of the mountain is about the same as the erosion that occurs at the mountain top. This means that the total weight of the crust above the mantle is relatively stable.
But this balanced erosion rate was thrown out of whack when the River Arun started taking in more water thousands of years ago. As more rocks were washed away by rivers, the earth’s crust rose in certain places.
Given that the elastic thickness of the Earth’s crust is between 10 and 30 km, the researchers estimate that this phenomenon would increase Chomolungma’s surface rise rate by up to 0.53 mm per year.
The discovery suggests that the tallest mountains on Earth today may have continued to grow from the formation of river canyons 89,000 years ago.
This research natural earth science.
