The Himalayan mountain range is situated in Asia, which spans the countries of Bhutan, Nepal, China and India. Its name comes from the Sanskrit ??????, Himalaya (pronounced jimaalaia) composed of hima word snow and ?laya: dwelling place. It is the highest mountain range on Earth, with ten of the fourteen peaks over 8000 meters, including Everest, with its 8848 m, the highest mountain in the world above the sea.
According to the theory of plate tectonics, the Himalayas is the result of the collision of the Indian plate and the Eurasian plate. This collision began in the Upper Cretaceous (about 70 million years ago), the Indian plate, heading north at a speed of 15 centimeters per year, collided with the Eurasian plate. The part of the Tethys Ocean, which separated completely disappeared about 50 million years ago. The Indian plate continues to move at a constant speed of about 5 centimeters per year, subducciéndose under the Eurasian plate and causing the elevation of the Himalayas and the Tibetan plateau.
The Indian plate pushes and distorts the Asian lithosphere in more than 3000 km north of the Himalayas. Tibet is cut by large faults that absorb this deformation. On the east side of the thrust of India, the chain of Arakan and the islands of Andaman and Nicobar in the Indian Ocean they have also been created by the movement between India and Eurasia.
This intense tectonic activity makes the region very active from the seismic standpoint. On the other hand, they are documented on the southern edge of the Himalayas historical earthquakes of magnitude 8 or more.
The most characteristic features of the Himalayas are their soaring heights, steep-sided jagged peaks, valley and alpine glaciers often of stupendous size, topography deeply cut by erosion, seemingly unfathomable river gorges, complex geologic structure, and series of elevational belts (or zones) that display different ecological associations of flora, fauna, and climate. Viewed from the south, the Himalayas appear as a gigantic crescent with the main axis rising above the snow line, where snowfields, alpine glaciers, and avalanches all feed lower-valley glaciers that in turn constitute the sources of most of the Himalayan rivers. The greater part of the Himalayas, however, lies below the snow line. The mountain-building process that created the range is still active. As the bedrock is lifted, considerable stream erosion and gigantic landslides occur.
The enormous size of the Himalayas has limited human migration between north and south. The differences are significant when religions, customs and languages of China and India are compared. Contacts have been few and conflicts have been avoided: this is how the Indian peninsula escaped the conquests of the Mongols of Genghis Khan.