Geologists have found a huge «gaps» in the mantle under Tibet

© RIA Novosti / Alexander Listenpreise in fotobounce structure of the EarthGeologists have found a huge «gaps» in the mantle under Tibet© RIA Novosti / Alexander Listenpreise in Photobacterium to daily updates RIA Science

Thank you for subscribing

Please check your e-mail to confirm your subscription

The collision of India and Eurasia led to the fact that the mantle under the future of the Indian subcontinent «exploded» into four separate segments. To such conclusion came the geologists, who published an article in the journal PNAS.

«The collision of Indian and Eurasian plates not only set the shape of the future of East Asia, but also caused some of the most powerful and deadly earthquakes in history. The presence of such discontinuities in the mantle explains why powerful earthquakes now occur not at all, and only in some regions of Tibet,» says Xiaodong song (Xiaodong Song) from the University of Illinois at Chicago (USA).

India, unlike many other regions of Eurasia, is a kind of geological «migrant». She was not part of the giant Eurasian tectonic plates initially, but joined to the continent relatively recently, about 65-70 million years ago. Prior to that, she was part of Gondwana, the southern supercontinent, and her «roommates» was Australia, Africa, Antarctica and South America.

When India separated from other parts of Gondwana, is not in dispute – it happened about 100 million years ago, when the Peninsula and Madagascar split and the Indian subcontinent began a journey to the North, in the direction of the future of Pakistan and India. On the other hand, when India collided with Asia and what happened during this collision, causing heated debate among scientists.

The answers to this question, according to the sun, is complicated by the fact that Tibet and the Himalayas remain one of the most remote and almost untouched by civilization corners of the Earth, which prevents their detailed study. His team solved this problem and revealed some interesting details about the history of this cataclysm, analyzing and combining data obtained during observations for recent large earthquakes in Tibet.

Measurements of transversal and longitudinal seismic waves have helped scientists to create a virtual copy of the bowels of Tibet to a depth of 160 kilometers, and understand where the line of contact between tectonic plates and how it works.

Unexpectedly it turned out that in the upper layers of the Earth mantle under the Tibetan plateau present four major gap in which flows the «sinking» of the Indian crust are moving not as in the neighboring regions of the earth. Different, as the researchers note, not only the speed but also the direction of flow of rocks.

This, in turn, explains many oddities related to the fact that earthquakes in the southern regions of Tibet often occur in the «wrong» parts of the plateau, where there is no strike-slip faults and seismic tension as well as strange nature of the eruptions at the time of forming a «seam» between the Indian plate and Eurasia.

How exactly did these gaps, scientists do not yet know, however, they suggest that they have arisen due to the fact that the edge of the Eurasian plate was initially very heterogeneous. Part of its margins was much more durable than other regions, which led to the «splitting» of the relatively weak areas of the mantle of the Indian plate into parts at the moment of their collision with each other.

This has led to the stretching of the crust and the emergence of additional fractures within it, which are now periodically spawn powerful earthquakes. Further monitoring of these gaps, as scientists hope will help reveal the history of the formation of the Peninsula and will allow us to better predict new tremors that are potentially dangerous for millions of residents of China, India, Nepal and Bhutan.

Source