Environment Snowdon

1 environment

1.1 flora
1.2 geology
1.3 climate
1.4 lakes

environment
flora

gagea serotina, snowdon lily , grows on cliffs of snowdon.

the environment of snowdon, particularly rare plants, has led designation national nature reserve. in addition plants widespread in snowdonia, snowdon home plants found elsewhere in britain. these include snowdon lily , gagea serotina, found in alps , in north america; first discovered in wales edward lhuyd, , genus lloydia (now included in gagea) later named in honour richard anthony salisbury. snowdon lies in northern part of snowdonia national park, has provided legal protection since park s establishment in 1951.

geology

the knife-edge arête of crib goch (foreground) , pyramidal peak of snowdon (background) both result of glaciation.

the rocks today make snowdon , neighbouring mountains formed in ordovician period. @ time, of modern-day wales near edge of avalonia, submerged beneath ancient iapetus ocean. in soudleyan stage (458 to 457 million years ago) of caradoc age, volcanic caldera formed, , produced ash flows of rhyolitic tuff, formed deposits 500 metres (1,600 ft) thick. current summit near northern edge of ancient caldera; caldera s full extent unclear, extended far summit of moel hebog in south-west.

snowdon , surrounding peaks have been described true examples of alpine topography . summits of snowdon , garnedd ugain surrounded cwms, rounded valleys scooped out glaciation. erosion glaciers in adjacent cwms caused characteristic arêtes of crib goch, crib y ddysgl , y lliwedd, , pyramidal peak of snowdon itself. other glacial landforms can seen around snowdon include roches moutonnées, glacial erratics , moraines.

climate

the english name snowdon comes old english snaw dun, meaning snow hill , snowdon has covering of snow. although amount of snow on snowdon in winter varies significantly, 55% less snow fell in 2004 in 1994. slopes of snowdon have 1 of wettest climates in great britain, receiving annual average of more 200 inches (5,100 mm) of precipitation.

lakes

llyn llydaw, largest , deepest lake on snowdon s flanks, crossed causeway @ eastern end.

a number of lakes found in various cwms of snowdon range.

llyn llydaw – 1,430 feet (440 m) high, 110 acres (45 ha) – lies in cwm dyli, snowdon s eastern cwm, , 1 of snowdonia s deepest lakes, @ 190 ft (58 m) deep. various explanations of name have been put forward, including lludw ( ash ), ashen deposits along shore, llydaw ( brittany ). contains evidence of crannog settlement, , location of 10-by-2-foot (3 m × 0.6 m) dugout canoe described in cambrian journal in 1862. lake coloured washings copper mines nearby, , used cwm dyli hydroelectric power station, opened in 1906. lake crossed causeway, built in 1853 , raised in 20th century prevent causeway flooding frequently.
glaslyn – 1,970 feet (600 m) high, 18 acres (7.3 ha) – lies higher cwm dyli llyn llydaw. called llyn y ffynnon glas, , has depth of 127 feet (39 m). long time, believed bottomless, , location various myths.
llyn ffynnon-y-gwas – 1,430 feet (440 m) high, 10 acres (4.0 ha) – lies in cwm treweunydd, snowdon s north-western cwm, , passed snowdon ranger path. enlarged damming use reservoir use slate quarries, level has since been lowered, , lake s volume reduced 24,000 cubic metres (850,000 cu ft).

other lakes include llyn du r arddu below clogwyn du r arddu – 1,901 feet (579 m) high, 5 acres (2.0 ha), llyn teyrn near pen-y-pass – 1,237 feet (377 m) high, 5 acres (2.0 ha), , several smaller pools.