79-626: Mallwyd ( Welsh pronunciation ) is a small village at the most southern end of Gwynedd , Wales, in the Mawddwy community, in the valley of the River Dyfi . It lies on the A470 approximately halfway between Dolgellau and Machynlleth , and forms the junction of the A458 towards Welshpool . The nearest villages are Dinas Mawddwy , two miles to the north, and Aberangell a similar distance to
158-527: A basal Permian unconformity into at least the western part of the Caernarfon Bay Basin. The timing of gas generation presents the greatest exploration risk. Maximum burial of, and primary gas migration from, the source rocks could have terminated as early as the Jurassic , whereas many of the tilted fault blocks were reactivated or created during Paleogene inversion of the basin. However, it
237-604: A continuation into British waters of Ireland's North Celtic Sea Basin, which has two producing gas fields. The basin comprises a south-easterly deepening half-graben near the Welsh coastline, although its internal structure becomes increasingly complex towards the southwest. Permian to Triassic, syn-rift sediments within the basin are less than 3 km (1.9 mi) thick and are overlain by up to 4 km (2.5 mi) of Jurassic strata, and locally also by up to 2 km (1.2 mi) of Paleogene fluvio-deltaic sediments. The basin has
316-459: A corresponding dosage of radioactivity naturally occurring in the seafood consumed by this group of 148 μSv (0.0148 rem) and a total average dosage in Ireland from all sources of 3,620 μSv (0.362 rem). In terms of risk to this group, heavy consumption of seafood generates a 1 in 18 million chance of causing cancer. The general risk of contracting cancer in Ireland is 1 in 522. In
395-459: A large extent on whether the seabed is composed of rock , boulders , gravel , sand , mud or even peat . In the soft sediments seven types of community have been provisionally identified, variously dominated by brittle-stars , sea urchins , worms, mussels , tellins , furrow-shells , and tower-shells. Parts of the bed of the Irish Sea are very rich in wildlife. The seabed southwest of
474-665: A plan to reintroduce grey whales by airlifting 50 of them from the Pacific Ocean to the Irish Sea was claimed to be logically and ethically feasible; it has not been implemented as of 2013. The common or harbour seal and the grey seal are both resident in the Irish Sea. Common seals breed in Strangford Lough, grey seals in southwest Wales and, in small numbers, on the Isle of Man. Grey seals haul out, but do not breed, off Hilbre and Walney islands, Merseyside ,
553-577: A proven petroleum system, with potentially producible gas reserves at the Dragon discovery near the UK/ROI median line, and oil shows in a further three wells. The Cardigan Bay Basin contains multiple reservoir targets, which include the Lower Triassic (Sherwood Sandstone), Middle Jurassic shallow marine sandstones and limestone (Great Oolite ), and Upper Jurassic fluvial sandstone, the reservoir for
632-533: A series of dramatic changes over the last 20,000 years as the last glacial period ended and was replaced by warmer conditions. At the height of the glaciation, the central part of the modern sea was probably a long freshwater lake. As the ice retreated 10,000 years ago, the lake reconnected to the sea. The Irish Sea was formed in the Neogene era. Notable crossings include several invasions from Britain. The Norman invasion of Ireland took place in stages during
711-626: A year. Holyhead port handles most of the passenger traffic from Dublin and Dún Laoghaire ports, as well as 3.3 million tonnes (3,200,000 long tons; 3,600,000 short tons) of freight. Ports in the Republic handle 3,600,000 travellers crossing the sea each year, amounting to 92% of all Irish Sea travel. Ferry connections from Wales to Ireland across the Irish Sea include Fishguard Harbour and Pembroke to Rosslare , Holyhead to Dún Laoghaire and Holyhead to Dublin. From Scotland , Cairnryan connects with both Belfast and Larne . There
790-712: Is also a connection between Liverpool and Belfast via the Isle of Man or direct from Birkenhead . The world's largest car ferry , Ulysses , is operated by Irish Ferries on the Dublin Port–Holyhead route; Stena Line also operates between Britain and Ireland. "Irish Sea" is also the name of one of the BBC 's Shipping Forecast areas defined by the coordinates: Iarnród Éireann , Irish Ferries , Northern Ireland Railways , ScotRail , Stena Line and Transport for Wales Rail promote SailRail with through rail tickets for
869-503: Is also possible that a secondary gas charge occurred during regional heating associated with intrusion of Paleogene dykes , such as those that crop out nearby on the coastline of north Wales. (Floodpage et al., 1999) have invoked this second phase of Paleogene hydrocarbon generation as an important factor in the charging of the East Irish Sea Basin's oil and gas fields. It is not clear as yet whether aeromagnetic anomalies in
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#1732783289035948-489: Is also very important for the local economy, including Bangor University and Further Education colleges, Coleg Meirion-Dwyfor and Coleg Menai , both now part of Grŵp Llandrillo Menai . Gwynedd has the highest proportion of people in Wales who can speak Welsh . According to the 2021 census , 64.4% of the population aged three and over stated that they could speak Welsh, while 64.4% noted that they could speak Welsh in
1027-489: Is based on tourism: many visitors are attracted by the many beaches and the mountains. A significant part of the county lies within the Snowdonia National Park , which extends from the north coast down to the district of Meirionnydd in the south. But tourism provides seasonal employment and thus there is a shortage of jobs in the winter. Agriculture is less important than in the past, especially in terms of
1106-692: Is bounded to the north and south by Lower Paleozoic massifs . Only two exploration wells have been drilled so far, and there remain numerous undrilled targets in tilted fault block plays . As in the East Irish Sea Basin, the principal target reservoir is the Lower Triassic, Sherwood Sandstone, top-sealed by younger Triassic mudstones and evaporites. Wells in the Irish Sector to the west have demonstrated that pre-rift, Westphalian coal measures are excellent hydrocarbon source rocks, and are at peak maturity for gas generation (Maddox et al., 1995). Seismic profiles clearly image these strata continuing beneath
1185-518: Is closely associated with sediment activity, with muddy deposits on the seabed acting as sinks, soaking up an estimated 200 kg (440 lb) of plutonium . The highest concentration is found in the eastern Irish Sea in sediment banks lying parallel to the Cumbrian coast. This area acts as a significant source of wider contamination as radionuclides are dissolved once again. Studies have revealed that 80% of current seawater contamination by caesium
1264-517: Is no top-seal for reservoirs sub cropping the regional base Permian unconformity in the east of the basin, and Carboniferous strata crop out at the sea bed in the west. Previous exploration drilling in the Kish Bank Basin has confirmed the potential for petroleum generation with oil shows seen in a number of wells together with natural hydrocarbon seeps recorded from airborne surveys. New analysis of vintage 2-D seismic data has revealed
1343-560: Is protected by the Llŷn AONB . Gwynedd also contains several of Wales's largest lakes and reservoirs, including the largest, Bala Lake ( Llyn Tegid ). The area which is now the county has played a prominent part in the history of Wales. It formed part of the core of the Kingdom of Gwynedd and the native Principality of Wales , which under the House of Aberffraw remained independent from
1422-465: Is sourced from sediment banks, whilst plutonium levels in the western sediment banks between the Isle of Man and the Irish coast are being maintained by contamination redistributed from the eastern sediment banks. The consumption of seafood harvested from the Irish Sea is the main pathway for exposure of humans to radioactivity. The environmental monitoring report for the period 2003 to 2005 published by
1501-470: The 2011 census . It is estimated that 83% of the county's Welsh-speakers are fluent, the highest percentage of all counties in Wales. The age group with the highest proportion of Welsh speakers in Gwynedd were those between ages 5 and 15, of whom 92.3% stated that they could speak Welsh in 2011. The proportion of Welsh speakers in Gwynedd declined between 1991 and 2001, from 72.1% to 68.7%, even though
1580-541: The Bahama and King William Banks to the east and north of the Isle of Man and the Kish Bank , Codling Bank, Arklow Bank and Blackwater Bank near the coast of Ireland. The Irish Sea, at its greatest width, is 200 km (120 mi) and narrows to 75 km (47 mi). The International Hydrographic Organization defines the limits of the Irish Sea (with St George's Channel) as follows, The Irish Sea has undergone
1659-691: The Celtic Sea in the south by St George's Channel and to the Inner Seas off the West Coast of Scotland in the north by the North Channel . Anglesey , North Wales , is the largest island in the Irish Sea, followed by the Isle of Man . The term Manx Sea may occasionally be encountered ( Welsh : Môr Manaw , Irish : Muir Meann Manx : Mooir Vannin , Scottish Gaelic : Muir Mhanainn ). On its shoreline are Scotland to
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#17327832890351738-873: The Douglas Complex the gas is piped by subsea pipeline to the Point of Ayr gas terminal for further processing. The gas is then sent by onshore pipeline to PowerGen 's combined cycle gas turbine power station at Connah's Quay . PowerGen is the sole purchaser of gas from the Liverpool Bay development. The Liverpool Bay development comprises four offshore platforms. Offshore storage and loading facilities. The onshore gas processing terminal at Point of Ayr. Production first started at each field as follows: Hamilton North in 1995, Hamilton in 1996, Douglas in 1996, Lennox (oil only) in 1996 and Hamilton East 2001. The first contract gas sales were in 1996. The quality of
1817-614: The Kingdom of England until Edward I 's conquest between 1277 and 1283. Edward built the castles at Caernarfon and Harlech , which form part of the Castles and Town Walls of King Edward in Gwynedd World Heritage Site . During the Industrial Revolution the slate industry rapidly developed; in the late nineteenth century the neighbouring Penrhyn and Dinorwic quarries were the largest in
1896-576: The Local Government Act 1972 . It covered the entirety of the historic counties of Anglesey and Caernarfonshire , and all of Merionethshire apart from Edeirnion Rural District (which went to Clwyd ); and also a few parishes of Denbighshire : Llanrwst , Llansanffraid Glan Conwy , Eglwysbach , Llanddoged, Llanrwst and Tir Ifan. The county was divided into five districts : Aberconwy , Arfon , Dwyfor , Meirionnydd and Anglesey . The Local Government (Wales) Act 1994 abolished
1975-705: The North Atlantic at both its northern and southern ends. To the north, the connection is through the North Channel between Scotland and Northern Ireland and the Malin Sea . The southern end is linked to the Atlantic through the St George's Channel between Ireland and Pembrokeshire , and the Celtic Sea . It is composed of a deeper channel about 300 km (190 mi) long and 30–50 km (20–30 mi) wide on its western side and shallower bays to
2054-537: The North Channel to see if a tunnel between Ireland and Scotland was viable. Sixty years later, Harford Montgomery Hyde , Unionist MP for North Belfast, called for the building of such a tunnel. A tunnel project has been discussed several times in the Irish parliament . The idea for a 34-kilometre (21 mi) long rail bridge or tunnel continues to be mooted. Several potential projects have been proposed, including one between Dublin and Holyhead put forward in 1997 by
2133-504: The Radiological Protection Institute of Ireland (RPII) reported that in 2005 average quantities of radioactive contamination found in seafood ranged from less than 1 Bq/kg (12 pCi/lb) for fish to under 44 Bq/kg (540 pCi/lb) for mussels. Doses of man-made radioactivity received by the heaviest consumers of seafood in Ireland in 2005 was 1.10 μSv (0.000110 rem). This compares with
2212-453: The Wirral , St Annes, Barrow-in-Furness Borough, and Cumbria. The Irish Sea has been described by Greenpeace as the most radioactively contaminated sea in the world with some "eight million litres of nuclear waste " discharged into it each day from Sellafield reprocessing plants, contaminating seawater, sediments and marine life. Low-level radioactive waste has been discharged into
2291-783: The sea duck , common scoter , spend winters feeding in shallow waters off eastern Ireland, Lancashire and North Wales . Whales, dolphins and porpoises all frequent the Irish Sea, but knowledge of how many there may be and where they go is somewhat sketchy. About a dozen species have been recorded since 1980, but only three are seen fairly often. These are the harbour porpoise , bottlenose dolphin and common dolphin . The more rarely seen species are minke whale , fin whale , sei whale , humpback whale , North Atlantic right whales which are now considered to be almost extinct in eastern North Atlantic, sperm whale , northern bottlenose whale , long-finned pilot whale , orca , white-beaked dolphin , striped dolphin and Risso's dolphin . In 2005,
2370-462: The 1974 county (and the five districts) on 1 April 1996, and its area was divided: the Isle of Anglesey became an independent unitary authority, and Aberconwy (which included the former Denbighshire parishes) passed to the new Conwy County Borough . The remainder of the county was constituted as a principal area, with the name Caernarfonshire and Merionethshire , as it covers most of the areas of those two historic counties. As one of its first actions,
2449-573: The British engineering firm Symonds. At 80 km (50 mi), it would have been by far the longest rail tunnel on earth with an estimated cost approaching £20 billion. An offshore wind farm was developed on the Arklow Bank, Arklow Bank Wind Park , about 10 km (6.2 mi) off the coast of County Wicklow in the south Irish Sea. The site currently has seven GE 3.6 MW turbines , each with 104-metre (341 ft) diameter rotors ,
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2528-523: The Council renamed itself Gwynedd on 2 April 1996. The present Gwynedd local government area is governed by Gwynedd Council . As a unitary authority , the modern entity no longer has any districts, but Arfon, Dwyfor and Meirionnydd remain as area committees . The pre-1996 boundaries were retained as a preserved county for a few purposes such as the Lieutenancy . In 2003, the boundary with Clwyd
2607-575: The Dee Estuary and the estuaries are also important as nurseries for flatfish , herring and sea bass . Muddy seabeds in deeper waters are home to populations of the Dublin Bay prawn , also known as "scampi". The open sea is a complex habitat in its own right. It exists in three spatial dimensions and also varies over time and tide. For example, where freshwater flows into the Irish Sea in river estuaries its influence can extend far offshore as
2686-478: The Dragon discovery. The most likely hydrocarbon source rocks are Early Jurassic marine mudstones. These are fully mature for oil generation in the west of the British sector and are mature for gas generation nearby in the Irish sector. Gas-prone, Westphalian pre-rift coal measures may also be present at depth locally. The Cardigan Bay Basin was subjected to two Tertiary phases of compressive uplift, whereas maximum burial that terminated primary hydrocarbon generation
2765-715: The East Irish Sea Basin is at a mature exploration phase. Early Namurian basinal mudstones are the source rocks for these hydrocarbons. Production from all fields is from fault-bounded traps of the Lower Triassic formation, principally the aeolian Sherwood Sandstone reservoir, top-sealed by younger Triassic continental mudstones and evaporites . Future mineral exploration will initially concentrate on extending this play , but there remains largely untested potential also for gas and oil within widespread Carboniferous fluvial sandstone reservoirs. This play requires intraformational mudstone seal units to be present, as there
2844-762: The Irish Sea and its surrounding coastline, ranging from flower-like fan-worms to predatory swimming crabs to large chameleon -like cuttlefish . Some of the most significant for other wildlife are the reef-building species like the inshore horse mussel of Strangford Lough, the inter-tidal honeycomb worm of Morecambe Bay, Cumbria and Lancashire , and the sub-tidal honeycomb worm of the Wicklow Reef . These build up large structures over many years and, in turn, provide surfaces, nooks and crannies where other marine animals and plants may become established and live out some or all of their lives. There are quite regular records of live and stranded leatherback turtles in and around
2923-453: The Irish Sea are of international importance for birds. They are vital feeding grounds on migration flyways for shorebirds travelling between the Arctic and Africa. Others depend on the milder climate as a refuge when continental Europe is in the grip of winter. Twenty-one species of seabird are reported as regularly nesting on beaches or cliffs around the Irish Sea. Huge populations of
3002-408: The Irish Sea as part of operations at Sellafield since 1952. The rate of discharge began to accelerate in the mid- to late 1960s, reaching a peak in the 1970s and generally declining significantly since then. As an example of this profile, discharges of plutonium (specifically Pu ) peaked in 1973 at 2,755 terabecquerels (74,500 Ci) falling to 8.1 TBq (220 Ci) by 2004. Improvements in
3081-473: The Irish Sea. This species travels north to the waters off the British Isles every year following the swarms of jellyfish that form its prey. Loggerhead turtle, ridley sea turtle and green turtle are found very occasionally in the Irish Sea but are generally unwell or dead when discovered. They have strayed or been swept out of their natural range further south into colder waters. The estuaries of
3160-477: The Isle of Man is particularly noted for its rarities and diversity, as are the horse mussel beds of Strangford Lough. Scallops and queen scallops are found in more gravelly areas. In the estuaries, where the bed is more sandy or muddy, the number of species is smaller but the size of their populations is larger. Brown shrimp , cockles and edible mussels support local fisheries in Morecambe Bay and
3239-786: The Middle Jurassic section. The Liverpool Bay Development was BHP 's largest operated asset. It comprises the integrated development of five offshore oil and gas fields in the Irish Sea: Oil is produced from the Lennox and Douglas fields. It is then treated at the Douglas Complex and piped 17 km (11 mi) to an oil storage barge ready for export by tankers. Gas is produced from the Hamilton, Hamilton North and Hamilton East reservoirs. After initial processing at
Mallwyd - Misplaced Pages Continue
3318-474: The North Channel of around six months with peak concentrations off the northeast Irish coast occurring 18–24 months after peak discharge. Less soluble elements such as plutonium are subject to much slower redistribution. Whilst concentrations have declined in line with the reduction in discharges they are markedly higher in the eastern Irish Sea compared to the western areas. The dispersal of these elements
3397-610: The Snowdonia National Park Authority; Conwy County Borough Council appoints three; and the Welsh Government appoints the remaining six. There has been considerable inwards migration to Gwynedd, particularly from England. According to the 2021 census, 66.6% of residents had been born in Wales whilst 27.1% were born in England. The county has a mixed economy. An important part of the economy
3476-537: The UK, the heaviest seafood consumers in Cumbria received a radioactive dosage attributable to Sellafield discharges of 220 μSv (0.022 rem) in 2005. This compares to average annual dose of naturally sourced radiation received in the UK of 2,230 μSv (0.223 rem). Discussions of linking Britain to Ireland began in 1895, with an application for £15,000 towards the cost of carrying out borings and soundings in
3555-400: The adjoining shores , the seabed and the open sea itself. The information on the invertebrates of the seabed of the Irish Sea is rather patchy because it is difficult to survey such a large area, where underwater visibility is often poor and information often depends upon looking at material brought up from the seabed in mechanical grabs. However, the groupings of animals present depend to
3634-430: The administrative centre is Caernarfon . The preserved county of Gwynedd, which is used for ceremonial purposes, includes the Isle of Anglesey . Gwynedd is the second largest county in Wales but sparsely populated, with an area of 979 square miles (2,540 km ) and a population of 117,400. After Bangor (18,322), the largest settlements are Caernarfon (9,852), Bethesda (4,735), and Pwllheli (4,076). The county has
3713-588: The bowl 1734, was a gift of Sir John Mytton of Dinas Mawddwy . Gwynedd Gwynedd ( Welsh: [ˈɡwɨnɛð] ) is a county in the north-west of Wales . It borders Anglesey across the Menai Strait to the north, Conwy , Denbighshire , and Powys to the east, Ceredigion over the Dyfi estuary to the south, and the Irish Sea to the west. The city of Bangor is the largest settlement, and
3792-448: The church which was put up to commemorate the 200th anniversary of his death. Outside the church are several great yew trees. The timber bell tower of the church is inscribed: SOLI DEO SACRUM ANNI CHRISTI MDCXL. It formerly also read VENITE CANTEM[us domino] A.D.1640 HONOR DEO IN EXCELSIS. The portals of the church, found between the church and the river, are decorated with fossil mammal bones. The black marble, octagonal font, dated below
3871-426: The east. The depth of the western channel ranges from 80 m (260 ft) to 275 m (900 ft). Cardigan Bay in the south, and the waters to the east of the Isle of Man , are less than 50 m (160 ft) deep. With a total water volume of 2,430 km (580 cu mi) and a surface area of 47,000 km (18,000 sq mi), 80% is to the west of the Isle of Man. The largest sandbanks are
3950-408: The freshwater is lighter and "floats" on top of the much larger body of salt water until wind and temperature changes mix it in. Similarly, warmer water is less dense and seawater warmed in the inter-tidal zone may "float" on the colder offshore water. The amount of light penetrating the seawater also varies with depth and turbidity. This leads to differing populations of plankton in different parts of
4029-753: The greatest wildlife resource of the Irish Sea lies in its estuaries : particularly the Dee Estuary , the Mersey Estuary , the Ribble Estuary , Morecambe Bay , the Solway Firth , the Firth of Clyde , Belfast Lough , Strangford Lough , Carlingford Lough , Dundalk Bay , Dublin Bay and Wexford Harbour . However, a lot of wildlife also depends on the cliffs, salt marshes and sand dunes of
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#17327832890354108-511: The highest percentage of Welsh speakers in Wales, at 64.4%, and is considered a heartland of the language . The geography of Gwynedd is mountainous, with a long coastline to the west. The county contains much of Snowdonia ( Eryri ), a national park which contains Wales's highest mountain, Snowdon ( Yr Wyddfa ; 3,560 feet, 1,090 m). To the west, the Llŷn Peninsula is flatter and renowned for its scenic coastline, part of which
4187-649: The late 12th century from Porthclais near St. Davids , Wales , in Hulks , Snekkars , Keels and Cogs to Wexford Harbour , Leinster . The Tudors crossed the Irish Sea to invade in 1529 in caravels and carracks . In 1690 the English fleet set sail for the Williamite War in Ireland from Hoylake , Wirral , the departure becoming permanently known as King's Gap as a result. Because Ireland has neither tunnel nor bridge to connect it with Great Britain ,
4266-927: The name and the Irish Féni , an early ethnonym for the Irish themselves, related to fían , 'company of hunting and fighting men, company of warriors under a leader'. Perhaps *u̯en-, u̯enə ('strive, hope, wish') is the Indo-European stem. The Irish settled in NW Wales, and in Dyfed , at the end of the Roman era. Venedotia was the Latin form, and in Penmachno there is a memorial stone from c. AD 500 which reads: Cantiori Hic Iacit Venedotis ('Here lies Cantiorix, citizen of Gwynedd'). The name
4345-478: The neighbouring community of Llanymawddwy to become the new community of Mawddwy. In 1867, the Mawddwy Railway was opened, connecting Dinas Mawddwy with Cemmaes Road . A small station was provided to serve Mallwyd, though it was nearly a mile from the village. Passenger services on the railway were withdrawn in 1931, and the railway closed and was lifted in 1952. According to tradition, Mallwyd church
4424-560: The north, England to the east, Wales to the southeast, Northern Ireland and the Republic of Ireland to the west. The Irish Sea is of significant economic importance to regional trade, shipping and transport, as well as fishing and power generation in the form of wind power and nuclear power plants . Annual traffic between Great Britain and Ireland is over 12 million passengers and 17 million tonnes (17,000,000 long tons; 19,000,000 short tons) of traded goods. The Irish Sea joins
4503-425: The number of people who earn their living on the land, but it remains an important element of the economy. The most important of the traditional industries is the slate industry, but these days only a small percentage of workers earn their living in the slate quarries. Industries which have developed more recently include TV and sound studios: the record company Sain has its HQ in the county. The education sector
4582-447: The partners are currently advancing a focused work programme in order to better understand and hopefully mitigate these risks. However, given its location in shallow water and close proximity to shore, the prospect is of great interest as exploration drilling, together with any future development costs, are likely to be low. Below is a list of cities and towns around the Irish Sea coasts in order of size: The most accessible and possibly
4661-654: The presence of a large undrilled structural closure at Lower Triassic level situated about 10 kilometres (6 mi) offshore Dublin. This feature, known as the Dalkey Island exploration prospect, may be prospective for oil, as there are prolific oil productive Lower Triassic reservoirs nearby in the eastern Irish Sea offshore Liverpool. Whilst the Dalkey Island exploration prospect could contain about 870 million barrels (140,000,000 m ) of oil in place, this undrilled prospect still has significant risk and
4740-405: The proportion of Welsh speakers in Wales as a whole increased during that decade to 20.5%. The Annual Population Survey estimated that as of March 2023, 77.0% of those in Gwynedd aged three years and above could speak Welsh. Irish Sea The Irish Sea is a 46,007 km (17,763 sq mi) body of water that separates the islands of Ireland and Great Britain . It is linked to
4819-401: The sea and varying communities of animals that feed on these populations. However, increasing seasonal storminess leads to greater mixing of water and tends to break down these divisions, which are more apparent when the weather is calm for long periods. Plankton includes bacteria, plants ( phytoplankton ) and animals ( zooplankton ) that drift in the sea. Most are microscopic, but some, such as
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#17327832890354898-536: The south. The River Dugoed flows into the River Dyfi near the village. The Cambrian Way long-distance walk passes through the village. The village is near the boundary between the historic counties of Merioneth and Montgomeryshire , in the parish of Mallwyd in the district of Mawddwy. This was the region of the Red Bandits of Mawddwy , which is remembered in name of the village pub, The Brigands. Mallwyd
4977-460: The southeast of Caernarfon Bay are imaging a continuation of the dyke swarm into this area too, or whether they are instead associated with deeply buried Permian syn-rift volcanics . Alternatively, the fault block traps could have been recharged by exsolution of methane from formation brines as a direct result of the Tertiary uplift (cf. Doré and Jensen, 1996). The Cardigan Bay Basin forms
5056-587: The train and the ferry. The British ship LCT 326 sank in the Irish sea and was discovered in March 2020. In September 2021, the British Navy ship HMS Mercury was discovered; it sank in 1940. The British ship SS Mesaba was sunk by the Imperial German Navy U-118 in 1918 and discovered in 2022. This ship is well known for sailing near the Titanic and for attempting to warn the Titanic about dangerous icebergs. The Caernarfon Bay basin contains up to 7 cubic kilometres (1.7 cu mi) of Permian and Triassic syn-rift sediments in an asymmetrical graben that
5135-469: The treatment of waste in 1985 and 1994 resulted in further reductions in radioactive waste discharge although the subsequent processing of a backlog resulted in increased discharges of certain types of radioactive waste. Discharges of technetium in particular rose from 6.1 TBq (160 Ci) in 1993 to a peak of 192 TBq (5,200 Ci) in 1995 before dropping back to 14 TBq (380 Ci) in 2004. In total 22 petabecquerels (590 kCi) of Pu
5214-460: The various species of jellyfish and sea gooseberry , can be much bigger. Diatoms and dinoflagellates dominate the phytoplankton. Although they are microscopic plants, diatoms have hard shells and dinoflagellates have little tails that propel them through the water. Phytoplankton populations in the Irish Sea have a spring "bloom" every April and May, when the seawater is generally at its greenest. Crustaceans , especially copepods , dominate
5293-531: The vast majority of heavy goods trade is done by sea. Northern Ireland ports handle 10 million tonnes (9,800,000 long tons; 11,000,000 short tons) of goods trade with the rest of the United Kingdom annually; the ports in the Republic of Ireland handle 7.6 million tonnes (7,500,000 long tons; 8,400,000 short tons), representing 50% and 40% respectively of total trade by weight. The Port of Liverpool handles 32 million tonnes (31,000,000 long tons; 35,000,000 short tons) of cargo and 734,000 passengers
5372-464: The water in Liverpool Bay was historically contaminated by dumping of sewage sludge at sea but this practice became illegal in December 1988 and no further sludge was deposited after that date. With 210 billion cubic metres (7.5 trillion cubic feet) of natural gas and 176 million barrels (28,000,000 m ) of petroleum estimated by the field operators as initially recoverable hydrocarbon reserves from eight producing fields (DTI, 2001),
5451-411: The world, and the Slate Landscape of Northwest Wales is now a World Heritage Site. Gwynedd covers the majority of the historic counties of Caernarfonshire and Merionethshire . In the past, historians such as J. E. Lloyd assumed that the Celtic source of the word Gwynedd meant 'collection of tribes' – the same root as the Irish fine , meaning 'tribe'. Further, a connection is recognised between
5530-465: The zooplankton. However, many animals of the seabed, the open sea and the seashore spend their juvenile stages as part of the zooplankton. The whole plankton "soup" is vitally important, directly or indirectly, as a food source for most species in the Irish Sea, even the largest. The enormous basking shark , for example, lives entirely on plankton and the leatherback turtle 's main food is jellyfish. A colossal diversity of invertebrate species live in
5609-399: Was adjusted to match the modern local government boundary, so that the preserved county now covers the two local government areas of Gwynedd and Anglesey. Conwy county borough is now entirely within Clwyd. A Gwynedd Constabulary was formed in 1950 by the merger of the Anglesey, Caernarfonshire and Merionethshire forces. A further amalgamation took place in the 1960s when Gwynedd Constabulary
5688-571: Was an ancient parish , which straddled the historic counties of Merioneth and Montgomeryshire. Under the Local Government Act 1894 parishes were no longer allowed to straddle county boundaries, and so the parts of the parish in Montgomeryshire became a separate parish called Caerinion Fechan, which later became part of Glantwymyn , leaving a smaller Mallwyd parish entirely in Merioneth. The parish of Mallwyd (which included Dinas Mawddwy)
5767-510: Was discharged over the period 1952 to 1998. Current rates of discharge for many radionuclides are at least 100 times lower than they were in the 1970s. Analysis of the distribution of radioactive contamination after discharge reveals that mean sea currents result in much of the more soluble elements such as caesium being flushed out of the Irish Sea through the North Channel about a year after discharge. Measurements of technetium concentrations post-1994 has produced estimated transit times to
5846-407: Was formed in 1951. After the 1974 local authority reorganisation, the park fell entirely within the boundaries of Gwynedd, and was run as a department of Gwynedd County Council. After the 1996 local government reorganisation, part of the park fell under Conwy County Borough , and the park's administration separated from the Gwynedd council. Gwynedd Council still appoints nine of the eighteen members of
5925-405: Was founded in the 6th century by Saint Tydecho after he came to the area from Cornwall . The present building dates from the 14th century and is unusual in form, being long and narrow with a balcony at each end. There are many wooden fixtures dating from the 17th century. The scholar John Davies was rector of Mallwyd for 40 years at the beginning of the 17th century. There is a memorial to him in
6004-493: Was made an urban district in 1895. The Mallwyd Urban District Council included Edward Hurst Davies in 1899 and 1900. It had an unusually small population for an urban district, with just 679 people in 1931. It was downgraded to a rural parish within Dolgellau Rural District in 1934. Rural parishes were converted into communities in 1974. Mallwyd community was subsequently abolished in 1985, merging with
6083-630: Was merged with the Flintshire and Denbighshire county forces, retaining the name Gwynedd. In one proposal for local government reform in Wales, Gwynedd had been proposed as a name for a local authority covering all of north Wales, but the scheme as enacted divided this area between Gwynedd and Clwyd. To prevent confusion, the Gwynedd Constabulary was therefore renamed the North Wales Police . The Snowdonia National Park
6162-588: Was probably around the end of the Cretaceous , or earlier if Cretaceous strata, now missing, were never deposited in the basin. Despite the Tertiary structuration, the Dragon discovery has proved that potentially commercial volumes of hydrocarbons were retained at least locally in Cardigan Bay. In addition to undrilled structural traps, the basin contains the untested potential for stratigraphic entrapment of hydrocarbons near synsedimentary faults, especially in
6241-528: Was retained by the Brythons when the kingdom of Gwynedd was formed in the 5th century, and it remained until the invasion of Edward I. This historical name was revived when the new county was formed in 1974. Gwynedd was an independent kingdom from the end of the Roman period until the 13th century, when it was conquered by England . The modern Gwynedd was one of eight Welsh counties created on 1 April 1974 under
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