The Younger Dryas was a return to glacial conditions after the Late Glacial Interstadial, which temporarily reversed the gradual climatic warming after the Last Glacial Maximum started receding around 20,000 BP. It is named after an indicator genus, the alpine-tundra wildflower Dryas octopetala, as its leaves are abundant in late glacial minerogenic-rich sediments, such as the lake sediments of Scandinavia. Physical evidence of a sharp decline in temperature over most of the Northern Hemisphere has been discovered by geological research; this temperature change occurred at the end of what the earth sciences refer to as the Pleistocene epoch and before the current, warmer Holocene epoch. In archaeology, this time frame coincides with the final stages of the Upper Paleolithic in many areas; the Younger Dryas was the most recent and longest of several interruptions to the gradual warming of the Earth's climate since the severe LGM, about 27,000 to 24,000 years BP. The change was sudden, taking place in decades, it resulted in a decline of 2 to 6°C and advances of glaciers and drier conditions, over much of the temperate Northern Hemisphere.
It is thought to have been caused by a decline in the strength of the Atlantic meridional overturning circulation, which transports warm water from the Equator towards the North Pole, in turn thought to have been caused by an influx of fresh, cold water from North America to the Atlantic. The Younger Dryas was a period of climatic change. In the Southern Hemisphere and some areas of the Northern Hemisphere, such as southeastern North America, a slight warming occurred; the presence of a distinct cold period at the end of the LGM interval has been known for a long time. Paleobotanical and lithostratigraphic studies of Swedish and Danish bog and lake sites, as in the Allerød clay pit in Denmark, first recognized and described the Younger Dryas; the Younger Dryas is the youngest and longest of three stadials, which resulted from abrupt climatic changes that took place over the last 16,000 years. Within the Blytt–Sernander classification of north European climatic phases, the prefix "Younger" refers to the recognition that this original "Dryas" period was preceded by a warmer stage, the Allerød oscillation, which, in turn, was preceded by the Older Dryas, around 14,000 calendar years BP.
That is not securely dated, estimates vary by 400 years, but it is accepted to have lasted around 200 years. In northern Scotland, the glaciers were more extensive than during the Younger Dryas; the Older Dryas, in turn, was preceded by another warmer stage, the Bølling oscillation, that separated it from a third and older stadial known as the Oldest Dryas. The Oldest Dryas occurred about 1,770 calendar years before the Younger Dryas and lasted about 400 calendar years. According to the GISP2 ice core from Greenland, the Oldest Dryas occurred between about 15,070 and 14,670 calendar years BP. In Ireland, the Younger Dryas has been known as the Nahanagan Stadial, in Great Britain, it has been called the Loch Lomond Stadial. In the Greenland Summit ice core chronology, the Younger Dryas corresponds to Greenland Stadial 1; the preceding Allerød warm period is subdivided into three events: Greenland Interstadial-1c to 1a. Since 1916 and the onset and the refinement of pollen analytical techniques and a steadily-growing number of pollen diagrams, palynologists have concluded that the Younger Dryas was a distinct period of vegetational change in large parts of Europe during which vegetation of a warmer climate was replaced by that of a cold climate, a glacial plant succession that contained Dryas octopetala.
The drastic change in vegetation is interpreted to be an effect of a sudden decrease in temperature, unfavorable for the forest vegetation, spreading northward rapidly. The cooling not only favored the expansion of cold-tolerant, light-demanding plants and associated steppe fauna, but led to regional glacial advances in Scandinavia and a lowering of the regional snow line; the change to glacial conditions at the onset of the Younger Dryas in the higher latitudes of the Northern Hemisphere, between 12,900 and 11,500 calendar years BP, has been argued to have been quite abrupt. It is in sharp contrast to the warming of the preceding Older Dryas interstadial, its end has been inferred to have occurred over a period of a decade or so, but the onset may have been faster. Thermally fractionated nitrogen and argon isotope data from Greenland ice core GISP2 indicate that its summit was around 15 °C colder during the Younger Dryas than today. In Great Britain, beetle fossil evidence suggests that the mean annual temperature dropped to −5 °C, periglacial conditions prevailed in lowland areas, icefields and glaciers formed in upland areas.
Nothing of the period's size, extent, or rapidity of abrupt climate change has been experienced since its end. In addition to the Younger and Oldest Dryases, a century-long period of colder climate, similar to the Younger Dryas in abruptness, has occurred within both the Bølling oscillation and the Allerød oscillation interstadials; the cold period that occurred within the Bølling oscillation is known as the intra-Bølling cold period, the cold period that occurred within the Allerød oscillation is known as the intra-Allerød cold period. Both cold periods are comparable in duration and intensity with the Older Dryas and began and ended quite abruptly; the cold periods have been recognized in sequence and relative magnitude in paleoclimatic records from Greenland ice cores, European lacustrine sediments, Atlantic Ocean s
The Lachlan River is an intermittent river, part of the Murrumbidgee catchment within the Murray–Darling basin, located in the Southern Tablelands, Central West, Riverina regions of New South Wales, Australia. The Lachlan River is connected to the Murray Darling basin only when both the Lachlan and Murrumbidgee Rivers are in flood, it is the only river in New South Wales with significant wetlands along its length, rather than just towards its end, including Lake Cowal-Wilbertroy, Lake Cargelligo and Lake Brewster, nine wetlands of national significance. The river rises on the western slopes of the Great Dividing Range in the Southern Tablelands district of New South Wales, formed by the confluence of Hannans Creek and Mutmutbilly Creek, 13 kilometres east of Gunning; the river flows north-west, north and south-west, joined by thirty-seven tributaries including the Crookwell, Abercrombie and Belubula rivers before terminating near Oxley in the 500-square-kilometre Great Cumbung swamp that joins the Murrumbidgee River to the south and becomes part of the Lowbidgee Floodplain.
The river descends 632 metres over its 1,440-kilometre course. The river is impounded by Wyangala Dam, near Cowra and Brewster Weir, located between Lake Cargelligo and Hillston; the annual flow of the Lachlan is erratic. Annual flows have ranged from less than 1,000 megalitres in 1944 to as much as 10,900 megalitres in 1950. In dry years, the Lachlan can have periods of zero flow of over a year, a complete contrast to the Murray and Murrumbidgee which have not been known to cease to flow since European settlement; the river has flooded every seven years since 1887 at Forbes. The social-ecological systems of the Lachlan River and its catchment include its upper tablelands, mixed farming slopes, through to plains and lower floodplains. More than 100,000 people live in the Lachlan catchment, it is estimated that 12% of the state's agricultural businesses are located from within the Lachlan River catchment. The Lachlan River is located in the traditional homelands of the Wiradjuri Aboriginal people.
The Wiradjuri lived along the Wambool, the Kalare and the Murrumbidjeri, in the area known as "the land of the three rivers."Acting-Surveyor George William Evans visited the river in 1815, naming it the Lachlan River after Lachlan Macquarie, the governor of the colony of New South Wales. The Lachlan River was explored by John Oxley in 1817. In the early days of colonial New South Wales, the southern part of the Lachlan was known as Fish River, it was only after further exploration that it was realised that these two rivers were the same river and the name Fish River was dropped. The explorer and naturalist, James H B Shaw, was one of the first Europeans to write about the birds and habitat along the Lachlan River, his article appeared in the Australian Town and Country Journal, Saturday 7 March 1885, page 28, 29 http://nla.gov.au/nla.news-article71024608 In 1870 the river peaked at 15.9 metres at Cowra. Since 1887, the highest flood level at Forbes was in June 1952 when the river peaked at 10.8 metres at the Forbes Iron Bridge.
More than 900 families were evacuated, with many rescued from roof-tops by helicopter. During the flood in August 1990, 132 houses in Forbes were affected by flood with their yards or their floors covered by water. Floods in 1992 did not reach the same levels at Forbes as in 1990, Lachlan Valley farmers lost about 30 percent of their lucerne crops just before harvest. At least 500 sheep were drowned on properties in the Eugowra/Trundle area and most of Eugowra's 400 residents were evacuated and some residents from Trundle. Other significant years of floods were: 1891, 1916, 1951, 1956, 1961, 1974, 1976, 1993, 1998 and 2016; the Lachlan River is mentioned in the Banjo Paterson poem Clancy of the Overflow. Lake Cowal List of rivers of New South Wales List of rivers of Australia Wyangala Dam "Lachlan River catchment". Office of Environment and Heritage. Government of New South Wales. Lachlan Catchment Management Authority website Trueman, Will. True Tales of the Trout Cod: River Histories of the Murray–Darling Basin.
The Lucknow Junction - Kathgodam Express is an express train belonging to North Eastern Railway zone that runs between Lucknow Junction and Kathgodam in India. It is being operated with 15043/15044 train numbers on a tri-weekly basis; the 15043/Lucknow Jn. - Kathgodam Express covers 341 km in 10h 5m. The 15044/Kathgodam - Lucknow Jn. Express covers 341 km in 7h 50m; the important halts of the train are: Lucknow Junction Bareilly Junction Bareilly City Izzatnagar Bhojipura Junction Baheri Kichha Pantnagar Lalkuan Junction Haldwani Kathgodam The train has standard ICF rakes with a max speed of 110 kmph. The train consist of 17 coaches: 1 AC II Tier 3 AC Chair Car 2 Second Sitting 3 Sleeper Coaches 6 General Unreserved 2 Seating cum Luggage Rake Both trains are hauled by a Gonda Loco Shed based WDM 3A diesel locomotive from Lucknow to Kathgodam and vice versa. Lucknow Junction railway station Kathgodam railway station 15043/Lucknow Jn. - Kathgodam Express 15044/Kathgodam - Lucknow Jn. Express