write down the features of Himalaya
Answers
Answer:
features of Himalayas are as follow down..
Explanation:
1.the act as a barrier between china and india.
2.they are the source of many perennial rivers.
3. their slopes are forested which provide us many products.
Answer:
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.
Machhapuchhare, Nepal
Machhapuchhare, Nepal
Machhapuchhare, a peak in the Great Himalaya Range, north-central Nepal.
© Digital Vision/Getty Images
The Himalayan ranges can be grouped into four parallel longitudinal mountain belts of varying width, each having distinct physiographic features and its own geologic history. They are designated, from south to north, as the Outer, or Sub-, Himalayas (also called the Siwalik Range); the Lesser, or Lower, Himalayas; the Great Himalaya Range (Great Himalayas); and the Tethys, or Tibetan, Himalayas. Farther north lie the Trans-Himalayas in Tibet proper. From west to east the Himalayas are divided broadly into three mountainous regions: western, central, and eastern.
Geologic history
Over the past 65 million years, powerful global plate-tectonic forces have moved Earth’s crust to form the band of Eurasian mountain ranges—including the Himalayas—that stretch from the Alps to the mountains of Southeast Asia.
cross section of the Himalayas
cross section of the Himalayas
Simplified north–south cross section of the Himalayas, revealing a foreland basin (Ganga Basin), an overthrusting of crystalline terrains onto the Indian Plate, and a steeper thrust fault (a ramp) beneath the Great Himalayas.
Encyclopædia Britannica, Inc.
During the Jurassic Period (about 201 to 145 million years ago), a deep crustal downwarp—the Tethys Ocean—bordered the entire southern fringe of Eurasia, then excluding the Arabian Peninsula and the Indian subcontinent. About 180 million years ago, the old supercontinent of Gondwana (or Gondwanaland) began to break up. One of Gondwana’s fragments, the lithospheric plate that included the Indian subcontinent, pursued a northward collision course toward the Eurasian Plate during the ensuing 130 to 140 million years. The Indian-Australian Plate gradually confined the Tethys trench within a giant pincer between itself and the Eurasian Plate. As the Tethys trench narrowed, increasing compressive forces bent the layers of rock beneath it and created interlacing faults in its marine sediments. Masses of granites and basalts intruded from the depth of the mantle into that weakened sedimentary crust. Between about 40 and 50 million years ago, the Indian subcontinent finally collided with Eurasia. The plate containing India was sheared downward, or subducted, beneath the Tethys trench at an ever-increasing pitch.
During the next 30 million years, shallow parts of the Tethys Ocean gradually drained as its sea bottom was pushed up by the plunging Indian-Australian Plate; that action formed the Plateau of Tibet. On the plateau’s southern edge, marginal mountains—the Trans-Himalayan ranges of today—became the region’s first major watershed and rose high enough to become a climatic barrier. As heavier rains fell on the steepening southern slopes, the major southern rivers eroded northward toward the headwaters with increasing force along old transverse faults and captured the streams flowing onto the plateau, thus laying the foundation for the drainage patterns for a large portion of Asia. To the south the northern reaches of the Arabian Sea and the Bay of Bengal rapidly filled with debris carried down by the ancestral Indus, Ganges (Ganga), and Brahmaputra rivers. The extensive erosion and deposition continue even now as those rivers carry immense quantities of material every day.