|
[[Image:Ireland.A2003004.jpg|thumb|right|300px|Ireland is sometimes known as the "Emerald Isle."]]
p3n15
The '''geography of Ireland''' reflects its situation as an [[island]] in northwest [[Europe]] in the north [[Atlantic Ocean]]. The ocean is responsible for the rugged western coastline, along which are many [[island]]s, [[peninsula]]s and [[headland]]s. The main geographical feature of [[Ireland]] is low central [[plain]]s surrounded by a ring of [[coast]]al [[mountains]]. The highest peak is [[Carrauntuohill]] ([[Irish language|Irish]]: ''Corrán Tuathail''), which is 1041 m (3414 feet). There are a number of sizable lakes along Ireland's rivers, with [[Lough Neagh]] the largest in the [[British Isles]]. The island is bisected by the [[River Shannon]], at 113 km (70 mi) the longest river in Ireland, which flows south from [[County Cavan]] in the north to meet the Atlantic just south of [[Limerick]]
The island of Ireland consists of the [[Republic of Ireland]] and [[Northern Ireland]]. Located west of the island of [[Great Britain]], it is approximately 53° north of the [[equator]] and 8° west of the [[Greenwich meridian]]. It has a total area of 84,116 km² (32,477 mi²). Ireland is separated from Britain by the [[Irish Sea]] and from mainland Europe by the [[Celtic Sea]].
<!-- Detail Regions of Ireland? Midlands, Northeast/North, Northwest, West, Mid-west/Golden vale, Southwest, sunny southeast, east. -->
== Physical geography ==
===Geology===
====Geological development====
[[Image:Slieve League-cliffs.jpg|thumb|300px|Slieve Liege in Donegal is a fine example of early Irish rock formation.]]
The oldest known Irish rock is about 1700 million years old and is found on the island of Inishtrahull off the coast of [[County Donegal]]. In other parts of Donegal, rocks have been discovered that began life as glacial deposits, demonstrating that at this early period, that part of what was to become Ireland was in the grip of an ice age. However, because of the effects of later upheavals, it is almost impossible to sequence these early rock layers correctly.
About 600 million years ago, at the end of the [[Precambrian]] era, the Irish landmass was divided in two, with one half on the western side of the [[Iapetus Ocean]] and the other at the eastern side, both at about the latitude that [[South Africa]] currently occupies. From the evidence of fossils found at [[Bray|Bray Head]] in [[County Wicklow]], Ireland was below [[sea level]] at this time.
Over the next 50 million years, these two parts drifted towards each other, eventually uniting about 440 million years ago. From fossils discovered near Clogher Head, [[County Louth]], we can see the coming together of shoreline fauna from both sides of the original dividing ocean. The mountains of north-west Ireland were formed during the collision as was the [[granite]] that is found in locations in Donegal and Wicklow.
The Irish landmass was now above sea level and lying near the [[Equator]] and fossil traces of land-based life forms survive from this period. These include fossilised trees from Kiltorcan, [[County Kilkenny]], widespread bony fish and freshwater mussel fossils and the footprints of a four-footed amphibian preserved in [[slate]] on Valentia Island, [[County Kerry]]. [[Old Red Sandstone]] also formed at this time.
Between 400 million and 300 million years ago, northwest [[Europe]], including Ireland, sank beneath a warm, [[calcium]]-rich sea. Great [[coral reef]]s formed in these waters, eventually forming the [[limestone]] that still forms about 65 percent of the rock mantle of the island. As the waters receded, [[tropical forest]]s and [[swamp]]s flourished. The resulting vegetable debris eventually formed coal, most of which was later eroded. This period, known as the [[Carboniferous]] era ended with further plate movement which saw Ireland drift further northward. The resulting pressure created those Irish mountain and hill ranges that run in a northeast to southwest direction.
[[Image:burren2.jpg|thumb|300px|left|Karstic landscape in the Burren]]
By 250 million years ago, Ireland was at the latitude of present-day [[Egypt]] and had a [[desert]] climate. It was at this time that most of the coal and sandstone were eroded. The thinner layers of limestone in the south of the country were also partially affected by this erosion. The limestone that was exposed by the disappearance of its sandstone mantle was affected by [[carbon dioxide]] and other factors resulting in a [[Karst|karstic]] landscape such as can still be seen in the [[Burren]] in [[County Clare]].
Shortly after this period, organic debris in the seas around Ireland began to form the gas and oil deposits that now play an important role in the island's economy. Then, about 150 million years ago, Ireland was again submerged, this time in a chalky sea that resulted in the formation of [[chalk]] over large parts of the surface. Traces of this survive under the [[basalt]] [[lava]] that is found in parts of the north.
About 65 million years ago, the volcanic activity that formed this lava began. The [[Mourne Mountains]] and other mountains in the northern part of the island formed as a result of this activity. Climatic conditions at this time were warm and vegetation thrived. Vegetable debris in the [[Antrim]] depression formed deposits of brown coal or [[lignite]] which remain untouched down to the present time. The warm conditions produced high rainfall that accelerated processes of erosion and the formation of karstic landscape forms.
By 25 million years ago, Ireland was close to assuming its present position. The long period of erosion had resulted in considerable soil formation and most of the rock mantle was covered. In areas with good drainage, the covering consisted of brown or grey [[soil]] while in poorly drained areas the black [[clay]] tended to dominate. As the climate cooled, soil formation slowed down and a [[flora]] and [[fauna]] that would, millions of years later, be familiar to the first human inhabitants began to emerge. By about three million years ago, the present landscape of Ireland had more or less formed.
Since about 1.7 million years ago, the world has been in the grip of a cycle of warm and cold stages and these have, inevitably, affected Ireland. The earliest evidence we have for this effect comes from the period known as the [[Ballylinian Warm Stage]], some half a million years ago. At this time, most of what are now considered to be native Irish trees were already established on the island. The action of the ice during the cold stages was the major factor in bringing the Irish landscape to its current form.
Obvious impacts of the ice on the landscape include the formation of glacial valleys such as [[Glendalough]] in Wicklow and of [[corrie]]s, or glacial lakes. The depositing of mounds of debris under the melting ice created [[drumlin]]s, a common feature of the landscape across the north midlands. Streams also formed under the ice and the material deposited by these formed [[esker]]s ([[Irish language|Irish]] ''eiscir''). The greatest of these, the Esker Riada, divides the northern and southern halves of the island and its ridge once server as the main highway connecting the east and west coasts.
====Rocks and soil types====
[[Image:Ireland-CliffsofMoher.jpg|right|framed|Layers of [[siltstone]], [[shale]] and [[sandstone]] can be seen in the [[Cliffs of Moher]], near [[Doolin]] in [[County Clare]]]]
The large central lowland is of [[limestone]] covered with glacial deposits of clay and sand, with widespread bogs and lakes. The [[Bog of Allen]] is one of the largest bogs. The coastal mountains vary greatly in geological structure. In the south, the mountains are composed of old red [[sandstone]] with limestone river valleys. In [[Galway]], [[County_Mayo|Mayo]], [[Donegal]], [[Down]] and [[Wicklow]], the mountains are mainly [[granite]], while much of the north-east of the country is a [[basalt]] plateau. An area of particular note is the [[Giant's Causeway]], in [[County Antrim]], a mainly basalt formation.
The soils of the north and west tend to be poorly drained peats and [[gley]]s, including peaty [[podzol]]s. In contrast, in the south and east the soils are free-draining brown earths and brown and grey-brown podzols. This is reflected in the rainfall distribution on the island, with the poorly-drained regions being those with the highest rainfalls.
A rather unique environment is present in north [[County Clare]], in an area known as [[The Burren]]. This [[karst|karst-like]] landscape consists of [[limestone]] bedrock, with little or no soil in the inner-most areas. There are numerous sink-holes, where surface water disappears through the porous rock surface, and extensive cave systems have been formed in some areas.
[[Image:Ireland_physical_medium.png|frame|right|Mountains, lakes, rivers and other physical features of [[Ireland]] are shown on this map ([[:Image:Ireland_physical_large.png|large version]]).]]
===Mountain Ranges===
Ireland consists of a mostly flat low-lying area in the midlands, ringed by mountain ranges such as (beginning in County Kerry and working anti-clockwise) the [[Macgillycuddy's Reeks]], [[Comeragh Mountains]], [[Blackstair Mountains]], [[Wicklow Mountains]], [[Mourne Mountains|the Mournes]], [[Glens of Antrim]], [[Sperrin Mountains]], [[Bluestack Mountains]], [[Derryveagh Mountains]], [[Ox Mountains]], [[Nephinbeg Mountains]] and the [[Twelve Bens]]/[[Maumturks]] group. Some mountain ranges are further inland in the south of Ireland, such as the [[Galtee Mountains]], [[Silvermines]] and [[Slieve Bloom Mountains]]. The highest peak is [[Carrauntuohill]], which is 1041 m (3414 feet) high. It is in the Macgillycuddy's Reeks, a range of [[glacier]]-carved [[sandstone]] mountains in [[County Kerry]], in the south-west of the island. The mountains are not high - only three peaks are over 1000m (just) and another 455 exceed 500m. [http://www.mountaineering.ie/features/list600/l600main.htm]
<!-- expand list to be a tour around the perimeter of the county, describing each range. Or add text in a topic for each chain.-->
===Rivers and lakes===
The main river in Ireland is the [[River Shannon]], 386 km (240 mi), the longest river in either [[Britain]] or [[Ireland]], which separates the boggy midlands of Ireland from the West of Ireland. The river develops into three lakes along its course, [[Lough Allen]], [[Lough Ree]] and [[Lough Derg (Munster)|Lough Derg]]. Of these, Lough Derg is the biggest. The River Shannon enters the [[Atlantic Ocean]] after [[Limerick city]] at the Shannon Estuary. Other major rivers include the [[River Liffey]], [[River Lee (Ireland)|River Lee]], [[River Blackwater]], [[River Nore]], [[River Suir]], [[River Barrow]] and [[River Boyne]]. See the [[list of rivers in Ireland]].
[[Lough Neagh]], in [[Ulster]] is the biggest lake in Ireland. Legend has it that a giant was fighting with another in Scotland, and enraged, scooped out a lump of earth, which he threw. It fell into the ocean, creating the [[Isle of Man]], while the hole filled up with water to become Lough Neagh. Other large lakes include [[Lough Erne]] and [[Lough Corrib]]. See the [[list of Irish loughs]].
===Inlets===
Beginning with [[County Donegal]], [[Lough Swilly]] separates one side of the Malin peninsula. [[Lough Foyle]] on the other side, is one of Ireland's larger inlets, situated between [[County Donegal]] and [[County Derry]]. Further round the coast is [[Belfast Lough]], between [[County Antrim]] and [[County Down]]. Also in County Down is [[Strangford Lough]], actually an inlet partially separating the [[Ards peninsula]] from the mainland. Further down the coast, [[Carlingford Lough]] is situated between Down and [[County Louth]].
[[Dublin Bay]] is the next sizable inlet, while the eastern coast of Ireland is mostly uniform until [[Wexford Harbour]] at the mouth of the [[River Slaney]]. On the southern coast, [[Waterford Harbour]] is situated at the mouth of the [[River Suir]] (into which the other two of the [[The Three Sisters (Ireland)|Three Sisters]] ([[River Nore]] and [[River Barrow]]) flow). The next major inlet is [[Cork Harbour]], at the mouth of the River Lee, in which [[Great Island]] is situated.
[[Dunmanus Bay]], [[Bantry Bay]], [[Kenmare River|Kenmare estuary]] and [[Dingle Bay]] are all inlets between the peninsulas of [[County Kerry]]. North of these is the [[River Shannon|Shannon estuary]]. Between north [[County Clare]] and [[County Galway]] is [[Galway Bay]].
[[Clew Bay]] is located on the coast of [[County Mayo]], south of [[Achill]], while [[Blacksod Bay]] is north of the island. [[Killala Bay]] is on the north coast of Mayo. [[Donegal Bay]] is a major inlet between [[County Donegal]] and [[County Sligo]].
===Headlands===
[[Malin Head]], [[County Donegal]] is the most northern point in Ireland, while [[Mizen Head]] is one of the most southern points, hence the term "Malin head to Mizen head" (or the reverse) is used for anything applying to the island of Ireland as a whole. [[Carnsore Point]], [[County Wexford]] is another [[extreme points of Ireland|extreme point of Ireland]], being the southeasternmost point of Ireland.
Further along the coast is [[Hook Head]], also in [[County Wexford]], while the [[Old Head of Kinsale]] in [[County Cork]] is one of many headlands along the south coast of Ireland.
[[Loop Head]] is the headland at which [[County Clare]] comes to a point on the west coast of Ireland, with the [[Atlantic Ocean|Atlantic]] on the north, and further inland on the south, the [[River Shannon|Shannon estuary]]. [[Hags Head]] is another headland further up Clare's north/western coastline, with the [[Cliffs of Moher]] along the coastline north of the point.
[[Erris Head]], [[County Mayo]] is the northwesternmost point of [[Connacht]].
===Islands and peninsulas===
[[Image:Dingle_Peninsula.jpg|thumb|left| Dingle Peninsula as viewed from [[Banna Strand]]]]
[[Achill Island]], [[County Mayo]] in the northwest of Ireland is the largest island off Ireland's coast. The island is inhabited, and is connected to the mainland by a bridge. Some of the next largest islands are the [[Aran Islands]], off the coast of [[County Galway]], host to an Irish-speaking community, or [[Gaeltacht]]. [[Valencia Island]] off the [[Iveragh peninsula]] in [[County Kerry]] is also one of Ireland's larger islands, and is relatively settled, as well as being connected by bridge at its southeastern end.
Some of the best-known peninsulas in Ireland are in [[County Kerry]]; the [[Dingle peninsula]], the aforementioned [[Iveragh peninsula]] and the [[Beara peninsula]]. The [[Ards peninsula]] in [[County Down]], is one of the larger peninsulas outside Kerry. The [[Inishowen]] Peninsula in [[Donegal]] includes Ireland's most northerly point, [[Malin Head]] and several important towns including [[Buncrana]] on [[Lough Swilly]], Carndonagh and Moville on [[Lough Foyle]].
Ireland's most northerly land feature is Inishtrahull island, off Malin Head, although [[Rockall]] Island may deserve this honour but its status is disputed, being claimed by the United Kingdom, Republic of Ireland, Denmark (for the Faroe Islands) and Iceland. Its most southerly is the [[Fastnet Rock]].
== Climate ==
Ireland's climate is [[temperate]], though significantly warmer than some other locations at similar [[latitude]], such as [[Poland]] (on the continent) or [[Newfoundland]] (on the opposite edge of the Atlantic), due to the warming influence of the [[North Atlantic drift]]. The prevailing wind blows from the south-west to the north-east, breaking on the high mountains of the west coast. [[Rain]]fall is therefore a particularly prominent part of western Irish life, with [[Valentia]], off the west coast of [[County Kerry]], getting almost twice as much annual rainfall as [[Dublin]] on the east (1400 [[millimetre|mm]] vs. 762 mm). Across the country, about 60% of the annual rainfall occurs betwen August and January.
January and February are the coldest months of the year, and mean daily air temperatures fall between 4°C and 7°C during these months. July and August are the warmest, with a range of 14°C to 16°C. The sunniest months are May and June, with an average of five to seven hours sunshine per day.
The table shows mean climate figures for the Dublin Airport weather station for the period [[1961]] to [[1990]]. Temperatures are in degrees [[Celsius]].
{|
| 