Mount Everest, also known as Chomolangma in Tibetan and Sagarmatha in Nepali, is about 15 to 50 meters higher than its original height due to uplift caused by erosion of nearby river canyons, and therefore continues to grow. This is revealed in a new study.
Han et al. They found that erosion from a network of rivers about 75 km from Everest had carved out a significant canyon. This landmass loss has caused mountains to rise by 2 mm per year, and their heights have already increased by 15 to 50 meters over the past 89,000 years. Image credit: truthseeker08.
The Himalayas, formed by the subduction of the Indian tectonic plate beneath the Eurasian plate, are home to some of the highest mountains on Earth.
Mount Everest is 8,849 meters above sea level, about 250 meters higher than the other highest peaks in the Himalayas.
Previous analysis of GPS data suggests that Everest's recent uplift is about 2 mm per year, which exceeds the expected uplift rate for the mountain range and suggests that mechanisms other than ongoing regional tectonics are responsible. This suggests that it may contribute to this process.
“Mount Everest is a remarkable mountain of myth and legend, and it continues to grow,” said Dr. Student Adam Smith.
“Our research shows that the nearby river system is cutting deeper and the loss of material is causing the mountain to spring further upwards.”
In this study, Smith and his colleagues investigated whether changes in rivers near the mountain may have contributed to Everest's recent uplift.
They used a numerical model to simulate the evolution of the Kosi river network and compared it to existing landforms.
These models suggest that the Arun River, a major tributary of the Kosi River, was involved in the occupation of another river 89,000 years ago.
The diversion of river water accelerated river erosion as the river adapted to its new path, resulting in the formation of the deep Arun River Gorge.
“Currently, the Arun River flows east of Mount Everest and joins the larger Kosi River system downstream,” Mr Smith said.
“For thousands of years, the River Arun has carved great gorges along its banks, washing away billions of tonnes of soil and sediment.”
“There are interesting river systems in the Everest region,” said Dr. Jing Geng Dai, a researcher at the China University of Geosciences.
“The upper Arun River flows eastward through highlands with flat valleys.''
“Then it suddenly turns south as the Kosi River, dropping in elevation and becoming steeper.”
“This unique feature of instability may be related to Everest's extreme height.”
The authors conclude that although erosion would have lowered local elevations along the river channel, the formation of the canyon removed the eroded mass relatively abruptly, allowing the surrounding landforms, including Everest, to compensate with surface uplift. It is argued that there is a possibility that
Although its contribution may be small compared to tectonic deformation, fluvial capture may play a role in both erosion and uplift of high landforms.
“Everest and its neighboring mountains are growing because isotropic rebound is causing them to rise faster than erosional wear,” said Dr. Matthew Fox, a researcher at University College London. said.
“Using GPS equipment, we can see it grow by about two millimeters every year. Now we can better understand what's causing that.”
“The change in the height of Mount Everest really highlights the dynamic nature of the Earth's surface,” says Dr. Xu Han, a researcher at the China University of Geosciences.
“The interaction between the erosion of the Arun River and the upward pressure of the Earth's mantle gives Everest a boost, pushing it higher than normal.”
of study Published in a magazine natural earth science.
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X Han others. The recent uplift of Chomolungma was reinforced by river drainage piracy. nut. earth sciencepublished online on September 30, 2024. doi: 10.1038/s41561-024-01535-w
Source: www.sci.news
