The collision of the Indian and Eurasian tectonic plates, which also led to the formation of the Himalayas, initiated complex underground processes that, based on new evidence, may lead to the splitting and liquidation of the Indian plate. According to a new study, the denser lower part of the Indian plate could separate under the Tibet region, causing a vertical fault that could also affect the risk of earthquakes.
The collision of the Indian and Eurasian tectonic plates, which also created the Himalayas, has set off complex underground processes that may have split the Indian plate, according to new evidence. According to a new study, the denser lower part of the Indian plate could separate under the Tibet region, causing a vertical fault that could also affect the risk of earthquakes.
The Himalayas, the highest mountain range on Earth, are the result of the ongoing collision of the Indian and Eurasian tectonic plates. This massive “collision,” which began about 60 million years ago, has dramatically reshaped the landscape: While the towering peaks are the visible signs of this collision, the real action is happening deep within the Earth, where tectonic plates interact in complex ways.
Based on traditional understanding, continental tectonic plates are not only thick, but also have high buoyancy, that is, their ability to float. This means that these plates do not easily sink into the Earth's mantle, the deepest layers underground, when they collide with other plates. But in this regard, the Indian plate in particular has been a subject of debate: some scientists believe it is sliding horizontally beneath Tibet, while others believe it is folded and subducted.
However, a recent study suggests a new and surprising scenario – Science Reports. According to them, part of the Indian plate undergoes “separation” (delamination) as it moves under the Eurasian plate: during this process, the denser lower part of the Indian plate separates from the upper part, which is accompanied by a vertical fracture or rupture. The discovery, presented at the American Geophysical Union conference in December 2023, represents a major step in understanding the formation of the Himalayas and regional earthquake hazards.
The concept of “decompressing” tectonic plates in this way is not new and has been explored in continental interiors and computer models, but the Himalayan collision is an ideal location to observe such phenomena due to the varied thickness and composition of the Indian plate.
The research included analyzing earthquake waves and studying the ratios of helium isotopes in Tibetan springs. These studies revealed patterns consistent with the plating theory. Additional seismic tests confirmed the presence of a rupture in the Indian plate.
Understanding these tectonic processes is crucial because almost all of Earth's land masses were formed by such collisions. The newly identified fault or fault may also influence the current seismic hazard in Tibet, suggesting a deeper relationship between subsurface tectonic activity and surface geological phenomena than previously thought.
(Image: Pixabay/Simon)
