Mount Everest has grown taller? Uncovering the secrets behind the river's invasion

Author: Duan Yuechu and Huang Yanhong

On our planet, Mount Everest stands like a towering giant in the Himalayas. Known as the "third pole of the earth", the highest peak in the world has always been one of the focuses of human exploration of the mysteries of nature. In recent years, the sudden "growth" of Mount Everest has attracted global attention. What secrets are hidden behind this strange phenomenon?

From the perspective of the macroscopic earth plate structure, the continuous convergence of the Indian Plate and the Eurasian Plate is the fundamental reason for the formation of the Himalayas. This grand geological movement has created many peaks on the earth, and Mount Everest is the best among them. It is nearly 8,849 meters above sea level, about 250 meters higher than the world's second highest peak, and overlooks the whole world with its majestic appearance.

Scientists have long studied the changes in the height of Mount Everest. By analyzing the data of the Global Positioning System (GPS), they discovered a surprising fact: Mount Everest has been rising at a rate of about 2 mm per year in recent years. This speed exceeds the expected rate of the overall uplift of the Himalayas. It is like a person in a group of people moving steadily forward suddenly speeds up and stands out. This phenomenon shows that in addition to the well-known cause of continuous regional tectonic movement, there must be other mechanisms that are secretly driving the uplift of Mount Everest.

In order to solve this mystery, Professor Dai Jingen and his colleagues from the team of Academician Wang Chengshan of China University of Geosciences (Beijing), together with other collaborators, conducted in-depth research. They focused on the changes in rivers near Mount Everest, trying to explore whether these rivers have some mysterious connection with the uplift of Mount Everest.

In their study, a river played a key role, that is, the Arun River. The research team used numerical models to simulate the evolution of the Arun River and its downstream network, and compared the simulation results with the current topography. This comparison was like opening a door to the past, allowing them to discover an astonishing event that occurred about 89,000 years ago: the Arun River once attacked the upper Pengqu.

River capture, in simple terms, is when one river seizes part of the course of another. This event is like a natural "river war" in which the Arun River emerged victorious. However, the impact of this victory far exceeded our imagination. When the Arun River successfully captured the Pongqu River, the river changed its course and the river eroded rapidly as it adapted to the new course. The force of this erosion was so strong that it eventually formed the deep Arun River Grand Canyon.

We may wonder, shouldn't river erosion reduce the height of the landform? Indeed, from a local perspective, river erosion does cause local reductions in elevation along the river. However, the magic of nature lies in its balance mechanism. When the canyon was formed, a large amount of material was taken away, which was like taking away a lot of weights from an originally balanced scale. In order to regain balance, the surrounding landforms will rise, and Mount Everest, as an important part of this area, is inevitably affected.

On the night of September 30, 2024, Nature Geoscience, a professional academic journal under Springer Nature, published this paper jointly completed by Chinese and foreign scientists online. Through detailed research and analysis, the authors of the paper estimated that this river capture event may have increased the elevation of Mount Everest by 15-50 meters. Although this number may not seem very amazing compared to the huge height of Mount Everest, it is of vital significance to our understanding of the uplift mechanism of Mount Everest.

From a broader perspective, river capture may be a relatively small contribution to topographic change compared to plate movement. Plate movement is like a grand, ongoing symphony of the Earth's crust, which determines the basic structure and direction of mountain ranges. However, river capture is like a unique note in the symphony, which is small but has its own melody. It can have important effects on regional erosion patterns and further uplift of mountains.

The mechanism of river capture affecting the rise of Mount Everest also makes us realize the complex relationship between various geological processes on the earth's surface. In the huge system of the earth, various geological processes do not exist in isolation, but are interrelated and influence each other. Just like a huge network, each node is inextricably linked to other nodes.

From the perspective of the river, the Arun River’s capture event changed the river system of the entire region. The original Pengqu River was cut off by the Arun River, and the Arun River’s water volume increased and its flow rate accelerated, thus exacerbating the erosion of the river channel. This erosion not only changed the shape of the river itself, but also affected the surrounding landforms through the transportation and redistribution of materials.

As for Mount Everest, the geological structure of the region where it is located is very complex. In addition to the huge thrust of plate movement, changes in the surrounding river system are also quietly changing its height. This impact may not be obvious in the short term, but as time accumulates, it gradually becomes apparent, manifested in the sudden "growth" of Mount Everest in recent years.

The significance of this research result is not limited to explaining the change in the height of Mount Everest. It also provides us with a new perspective to understand the geological evolution of other high mountain areas. In many high mountain areas in the world, the interaction between rivers and mountains is also an important research topic. For example, in the formation and evolution of the Alps and the Andes, are there similar river capture events that affect the height of the mountains? This is a direction that scientists can further explore in the future.

In addition, this study also has important implications for our understanding of the Earth's ecosystem. The unique geographical environment of the Mount Everest region has fostered rich biodiversity. As the height of Mount Everest changes, its climate, soil and other ecological factors will also change accordingly. These changes may affect the living environment of local animals and plants, and then affect the balance of the entire ecosystem. For example, as Mount Everest rises, the temperature may drop further, and some animals and plants that adapt to cold environments may migrate to higher altitudes, while some species originally in high-altitude areas may face survival challenges because the environment becomes too harsh.

From a human perspective, the height change of Mount Everest is also closely related to us. Mount Everest is a holy place for human mountaineering exploration. Every year, many brave climbers try to challenge the world's highest peak. The change in the height of Mount Everest may affect the climbing route, the difficulty of climbing, etc. At the same time, the Mount Everest area is also the source of many rivers, which provide water for people in the surrounding areas. If the geological changes in the Mount Everest area affect the water volume and water quality of the rivers, it will directly affect the lives and production of local residents.

In terms of scientific research, this achievement also inspires scientists to further explore the mysteries of the Earth. The Earth is a complex and mysterious planet, and our understanding of it is just the tip of the iceberg. Solving the mystery of Mount Everest's "growth" is just the beginning, and there are more geological phenomena waiting for us to discover and explain in the future. For example, we still need to further study the impact of other geological factors on the height of Mount Everest, as well as the interaction mechanism between these factors. At the same time, with the continuous development of technology, we can obtain more accurate measurement data, which will help us study the uplift process of Mount Everest more deeply.

In short, the phenomenon of Mount Everest's sudden "growth" in recent years hides a complex and mysterious geological mechanism. The discovery of the river capture event has revealed a corner of this mystery for us, allowing us to see the subtle and profound connection between the geological processes on the earth's surface. This research result not only enriches our understanding of Mount Everest, but also injects new vitality into the development of earth science, prompting us to continue to explore more unknown mysteries of this magical planet, the Earth.