HALCYON DAYS :


Halcyon Days, in Greek mythology, a period of two weeks of calm seas around the winter solstice, when the mythical halcyon (a bird identified with the kingfisher) brooded over a nest at sea. According to legend, Alcyone, a daughter of Aeolus, threw herself into the sea upon learning of her husband Ceyx's death during a voyage. She was transformed into a bird, and calm was assured for a period so that her eggs could hatch.

HIMALAYA :


I INTRODUCTION Himalaya, also Himalayas (Sanskrit for “abode of snow”), mountain system in Asia, comprising a series of parallel and converging ranges and forming the highest mountain region in the world. More than 30 peaks of the Himalaya rise to heights of 7,620 m (25,000 ft) or more, and one of these, Mount Everest (8,848 m/29,028 ft), is the world's highest mountain. The vast Himalayan complex extends in an arc of about 2,410 km (1,500 mi) from the River Indus in northern Pakistan eastwards across Kashmir in northern India, part of southern Tibet, and most of Nepal, the Indian state of Sikkim, and Bhutan; the system covers an area of about 594,400 sq km (229,500 sq mi).


II GEOLOGICAL FORMATION AND STRUCTURE During the Palaeozoic and Mesozoic eras (65 million to 570 million years ago) the area that is now the Himalaya occupied the floor of the ancient Tethys Sea on the northern part of the Indian Plate of the Earth's crust. The mountains were formed by the action of plate tectonics as the Indian Plate, moving north, pressed against the stationary Asian land mass. The principal uplift occurred during the middle or late Tertiary period (12 million to 65 million years ago). The ranges of the Himalayan system developed from north to south in a series of stages. Even today the system has not reached a state of equilibrium, and earthquakes are frequent.
The Himalaya consists primarily of metamorphic rocks; extensive areas of igneous rocks are in the south. Palaeozoic and Mesozoic marine sediments are found in several regions.


III TOPOGRAPHY The Himalaya can be divided into four parallel, longitudinal mountain belts of varying widths. From south to north these belts are the Outer Himalaya, or Sub-Himalaya; the Lesser Himalaya; the Great Himalaya; and the Tethys, or Tibetan Himalaya. The Outer Himalaya comprises the Siwalik Range, which rises steeply from the northern Indian plains and descends gently to flat-floored basins. To the north is the Lesser Himalaya, where the mountains rise to 4,572 m (15,000 ft) and the valleys lie at elevations of about 915 m (3,000 ft). The Great Himalaya, which forms the backbone of the Himalayan system, contains the main ranges and highest peaks and rises above the snow line to an average elevation of about 6,100 m (20,000 ft). The maximum height of these mountains is in Nepal, where 9 of the world's 14 highest peaks are found. Among these are Kanchenjunga, Dhaulagiri, and Annapurna in addition to Everest. The world's second highest mountain, K2, is in the Karakorum Range in the border area between Pakistan and China. To the north are the more complex Tibetan ranges and plateaux.
The passes in the Himalaya, which often lie along or across glaciers, are the highest in the world, with an average height of about 3,050 m (10,000 ft). All passes above about 4,880 m (16,000 ft) are closed by snow from November to May.


IV RIVERS, LAKES, AND GLACIERS The Himalaya is drained by several major Asian rivers, including the Brahmaputra, Indus, and the Sutlej, as well as by many of their important tributaries. The headwaters of the River Ganges are also in the Himalaya. Numerous small glacial lakes are found at the heads of gorges, but the largest lakes lie at comparatively low elevations. Above the snow line, in all parts of the Himalayan system, small glaciers are found. Several glaciers are as much as 48 km (30 mi) long; the majority, however, are less than half that size.


V CLIMATE Three seasons are generally recognizable in the Himalaya: a cold period from October to February, a hot period from March to June, and the south-western monsoon season with heavy rains (particularly in the east) from June to September. The high main range of the Himalaya forms a vast screen that intercepts and condenses nearly all moisture carried by the monsoons. This moisture is deposited on the southern face of the mountains, which have a heavy annual rainfall; the northern slopes are semi-arid or arid.
The elevation of the Himalaya also affects its temperature range. The climate on the southern side varies from subtropical at the base and valleys, through temperate at elevations of about 2,130 m (7,000 ft), to alpine, or tundra, at 3,660 m (12,000 ft). The line of permanent snow lies at about 5,030 m (16,500 ft). Strong winds prevail throughout in the high-elevation areas.


VI VEGETATION AND ANIMAL LIFE Vegetation is generally more lush in the east, where rainfall is heaviest. At elevations up to 610 m (2,000 ft), a zone of grass is found in the west, and a dense, swampy subtropical forest known as the Tarai is found in the east. At higher elevations is a monsoon forest in which sal, a close-grained hardwood, is the most characteristic tree. Evergreen oak and rhododendron predominate at 1,520 to 2,740 m (5,000 to 9,000 ft); the deodar cedar is also found here. Above this level, to an elevation of about 3,660 m (12,000 ft) are coniferous forests, and at higher elevations, extending to the snowline, lies an alpine zone of low shrubs and grasses. During the second half of the 20th century, many regions of the Lesser Himalaya have been deforested for firewood and to make room for agricultural development, resulting in severe erosion. In the Lesser Himalaya, only in Bhutan and parts of India are large regions still heavily forested.
Elephant, buffalo, and rhinoceros are restricted to certain areas of the forested Tarai. The Himalayan black bear, the clouded leopard, the langur monkey, and the goat antelope are widespread in the higher Himalayan forests. Above the tree line, the snow leopard, the brown bear, the red panda, and the Tibetan yak can occasionally be seen. The yak has been domesticated and is used as a beast of burden. Bird life is particularly rich in the eastern regions.