96-533: The Afon Cennen is a river in the county of Carmarthenshire , south Wales . It rises on the northern slopes of the Black Mountain to the east of the summit of Tair Carn Uchaf and flows north to Blaencennen Farm, then westwards past Carreg Cennen Castle , continuing through the village of Trap where it exits the Brecon Beacons National Park . Near the hamlet of Derwydd it turns northwest for
192-434: A tin-plating industry in the eighteenth century, with Llanelli following not long after, so that by the end of the nineteenth century, Llanelli was the world-centre of the industry. There is little trace of these industrial activities today. Llanelli and Burry Port served at one time for the export of coal , but trade declined, as it did from the ports of Kidwelly and Carmarthen as their estuaries silted up. Country towns in
288-564: A few decades. Cooling in Greenland was particularly rapid, taking place over just 3 years or less. At the same time, the Southern Hemisphere experienced warming. This period ended as rapidly as it began, with dramatic warming over ~50 years, which transitioned the Earth from the glacial Pleistocene epoch into the current Holocene . The Younger Dryas onset was not fully synchronized; in
384-502: A high latitude volcanic eruption could have accelerated North Atlantic sea ice growth, finally tipping the AMOC sufficiently to cause the Younger Dryas. Cave deposits and glacial ice cores both contain evidence of at least one major volcanic eruption taking place in the northern hemisphere at a time close to Younger Dryas onset, perhaps even completely matching the stalagmite-derived date for
480-570: A mile then northeast to run through the village of Ffairfach to its confluence with the River Towy opposite Llandeilo . The name could derive either from 'cen' meaning lichen or else from a personal name. 51°52′34″N 3°59′22″W / 51.87617°N 3.98941°W / 51.87617; -3.98941 Carmarthenshire Carmarthenshire ( / k ər ˈ m ɑːr ð ən ʃ ər , - ʃ ɪər / ; Welsh : Sir Gaerfyrddin [siːr gɑːɨrˈvərðɪn] or informally Sir Gâr )
576-596: A number of medieval castles, hillforts and standing stones . The Dylan Thomas Boathouse is at Laugharne . Stone tools found in Coygan Cave , near Laugharne indicate the presence of hominins , probably neanderthals , at least 40,000 years ago, though, as in the rest of the British Isles , continuous habitation by modern humans is not known before the end of the Younger Dryas , around 11,500 years BP . Before
672-501: A pathway along the Mackenzie River in present-day Canada, and sediment cores show that the strongest outburst had occurred right before the onset of Younger Dryas. Other factors are also likely to have played a major role in the Younger Dryas climate. For instance, some research suggests climate in Greenland was primarily affected by the melting of then-present Fennoscandian ice sheet , which could explain why Greenland experienced
768-468: A plant which only thrives in glacial conditions, began to dominate where forests were able to grow during the preceding B-A Interstadial. This makes the Younger Dryas a key example of how biota responded to abrupt climate change . For instance, in what is now New England , cool summers, combined with cold winters and low precipitation, resulted in a treeless tundra up to the onset of the Holocene, when
864-818: A productive coast with estuaries providing a range of foods that motivate many home cooks and chefs. Younger Dryas The Younger Dryas (YD, Greenland Stadial GS-1) was a period in Earth's geologic history that occurred circa 12,900 to 11,700 years Before Present (BP). It is primarily known for the sudden or "abrupt" cooling in the Northern Hemisphere, when the North Atlantic Ocean cooled and annual air temperatures decreased by ~3 °C (5.4 °F) over North America , 2–6 °C (3.6–10.8 °F) in Europe and up to 10 °C (18 °F) in Greenland , in
960-745: A scenic route through mid-Wales and links Llanelli with Craven Arms , from where passengers can travel on the Welsh Marches Line to Shrewsbury . Two heritage railways, the Gwili Railway and the Teifi Valley Railway , use the track of the Carmarthen and Cardigan Railway that at one time ran from Carmarthen to Newcastle Emlyn, but did not reach Cardigan . The A40 , A48 , A484 and A485 converge on Carmarthen. The M4 route that links South Wales with London , terminates at junction 49,
1056-630: Is a Roman amphitheatre nearby, so this probably makes Carmarthen the oldest continually occupied town in Wales. Carmarthenshire has its early roots in the region formerly known as Ystrad Tywi ('Vale of [the river] Tywi') and part of the Kingdom of Deheubarth during the High Middle Ages, with the court at Dinefwr . After the Normans had subjugated England they tried to subdue Wales. Carmarthenshire
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#17328772411611152-514: Is a county in the south-west of Wales . The three largest towns are Llanelli , Carmarthen and Ammanford . Carmarthen is the county town and administrative centre. The county is known as the "Garden of Wales" and is also home to the National Botanic Garden of Wales . Carmarthenshire has been inhabited since prehistoric times. The county town was founded by the Romans, and the region
1248-530: Is bounded to the north by Ceredigion , to the east by Powys (historic county Brecknockshire ), Neath Port Talbot (historic county Glamorgan ) and Swansea (also Glamorgan), to the south by the Bristol Channel and to the west by Pembrokeshire . Much of the county is upland and hilly. The Black Mountain range dominates the east of the county, with the lower foothills of the Cambrian Mountains to
1344-399: Is by far the largest town in the county, the county town remains Carmarthen, mainly due to its central location. Carmarthenshire is predominantly an agricultural county, with only the southeastern area having any significant amount of industry. The best agricultural land is in the broad Tywi Valley, especially its lower reaches. With its fertile land and agricultural produce, Carmarthenshire
1440-529: Is hypothesized to be the result of a northward shift in the jet stream, combined with an increase in summer insolation as well as a winter snow pack that was higher than today, with prolonged and wetter spring seasons. The Younger Dryas is often linked to the Neolithic Revolution , with the adoption of agriculture in the Levant . The cold and dry Younger Dryas arguably lowered the carrying capacity of
1536-465: Is known as the "Garden of Wales". The lowest bridge over the river is at Carmarthen, and the Towi Estuary cuts the southwesterly part of the county, including Llansteffan and Laugharne, off from the more urban southeastern region. This area is also bypassed by the main communication routes into Pembrokeshire. A passenger ferry service used to connect Ferryside with Llansteffan until the early part of
1632-675: Is made. On upland pastures and marginal land, livestock rearing of cattle and sheep is the main agricultural activity. The estuaries of the Loughor and Towy provide pickings for the cockle industry. Llanelli, Ammanford and the upper parts of the Gwendraeth Valley are situated on the South Wales Coalfield . The opencast mining activities in this region have now ceased but the old mining settlements with terraced housing remain, often centred on their nonconformist chapels. Kidwelly had
1728-465: Is reconstructed through proxy data such as traces of pollen , ice cores and layers of marine and lake sediments . Collectively, this evidence shows that significant cooling across the Northern Hemisphere began around 12,870 ± 30 years BP. It was particularly severe in Greenland , where temperatures declined by 4–10 °C (7.2–18.0 °F), in an abrupt fashion. Temperatures at the Greenland summit were up to 15 °C (27 °F) colder than at
1824-543: Is served by the main line railway service operated by Transport for Wales Rail which links London Paddington , Cardiff Central and Swansea to southwest Wales. The main hub is Carmarthen railway station where some services from the east terminate. The line continues westwards with several branches which serve Pembroke Dock , Milford Haven and Fishguard Harbour (for the ferry to Rosslare Europort and connecting trains to Dublin Connolly ). The Heart of Wales Line takes
1920-625: Is the largest historic county by area in Wales. The county is drained by several important rivers which flow southwards into the Bristol Channel , especially the River Towy, and its several tributaries, such as the River Cothi . The Towy is the longest river flowing entirely within Wales. Other rivers include the Loughor (which forms the eastern boundary with Glamorgan ), the River Gwendraeth and
2016-555: The 2001 census , 50.3 per cent of people living in Carmarthenshire could speak Welsh, with 39 per cent being able to read and write the language as well. The 2011 census showed a further decline, with 43.9 per cent speaking Welsh, making it a minority language in the county for the first time. However, the 2011 census also showed that 3,000 more people could understand spoken Welsh than in 2001 and that 60% of 5-14-year-olds could speak Welsh (a 5% increase since 2001). A decade later,
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#17328772411612112-592: The A486 and A487 to Aberystwyth , and the A485 links Carmarthen to Lampeter . Bus services run between the main towns within the county and are operated by First Cymru under their "Western Welsh" or "Cymru Clipper" livery. Bus services from Carmarthenshire are also run to Cardiff. A bus service known as " fflecsi Bwcabus" (formerly just "Bwcabus") operates in the north of the county, offering customised transport to rural dwellers. Carmarthenshire has rich, fertile farmland and
2208-494: The Court of Great Sessions in Wales in the town. The Normans transformed Carmarthen into an international trading port, the only staple port in Wales. Merchants imported food and French wines and exported wool, pelts, leather, lead and tin. In the late medieval period the county's fortunes varied, as good and bad harvests occurred, increased taxes were levied by England, there were episodes of plague , and recruitment for wars removed
2304-830: The Cymru Premier . They won the Welsh Football League Cup in the 1995–96 season, and since then have won the Welsh Cup once and the Welsh League Cup twice. Llanelli Town A.F.C. play in the Welsh Football League Division Two . The club won the Welsh premier league and Loosemores challenge cup in 2008 and won the Welsh Cup in 2011, but after experiencing financial difficulties, were wound up and reformed under
2400-665: The Heineken Cup . West Wales Raiders , based in Llanelli, represent the county in Rugby league . Some sporting venues utilise disused industrial sites. Ffos Las racecourse was built on the site of an open cast coal mine after mining operations ceased. Opened in 2009, it was the first racecourse built in the United Kingdom for eighty years and has regular race-days. Machynys is a championship golf course opened in 2005 and built as part of
2496-593: The Llanelli Waterside regeneration plan. Pembrey Circuit is a motor racing circuit near Pembrey village, considered the home of Welsh motorsport, providing racing for cars, motorcycles, karts and trucks. It was opened in 1989 on a former airfield, is popular for testing and has hosted many events including the British Touring Car Championship twice. The 2018 Tour of Britain cycling race started at Pembrey on 2 September 2018. Carmarthenshire
2592-648: The Nahanagan Stadial , and 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 (GS-1). The preceding Allerød warm period (interstadial) is subdivided into three events: Greenland Interstadial-1c to 1a (GI-1c to GI-1a). As with the other geologic periods, paleoclimate during the Younger Dryas
2688-630: The Pendine Museum of Speed and the West Wales Museum of Childhood all provide opportunities to delve into the past. Dylan Thomas Boathouse where the author wrote many of his works can be visited, as can the Roman-worked Dolaucothi Gold Mines . Activities available in the county include rambling, cycling, fishing, kayaking, canoeing, sailing, horse riding, caving, abseiling and coasteering. Carmarthen Town A.F.C. plays in
2784-649: The Pont Abraham services , to continue northwest as the dual carriageway A48 , and to finish with its junction with the A40 in Carmarthen. Llanelli is linked to M4 junction 48 by the A4138 . The A40 links Carmarthen to Llandeilo , Llandovery and Brecon to the east, and with St Clears , Whitland and Haverfordwest to the west. The A484 links Llanelli with Carmarthen by a coastal route and continues northwards to Cardigan , and via
2880-677: The Puerto Princesa cave complex in the Philippines shows that the onset of the Younger Dryas in East Asia was delayed by several hundred years relative to the North Atlantic. Further, the cooling was uniform throughout the year, but had a distinct seasonal pattern. In most places in the Northern Hemisphere, winters became much colder than before, but springs cooled by less, while there was either no temperature change or even slight warming during
2976-559: The River Taf . The River Teifi forms much of the border between Carmarthenshire and Ceredigion, and there are a number of towns in the Teifi Valley which have communities living on either side of the river and hence in different counties. Carmarthenshire has a long coastline which is deeply cut by the estuaries of the Loughor in the east and the Gwendraeth, Tywi and Taf, which enter the sea on
Afon Cennen - Misplaced Pages Continue
3072-671: The Romans arrived in Britain, the land now forming the county of Carmarthenshire was part of the kingdom of the Demetae who gave their name to the county of Dyfed ; it contained one of their chief settlements, Moridunum , now known as Carmarthen . The Romans established two forts in South Wales, one at Caerwent to control the southeast of the country, and one at Carmarthen to control the southwest. The fort at Carmarthen dates from around 75 AD, and there
3168-462: The Scandinavian ice sheet advanced. Notably, ice sheet advance in this area appears to have begun about 600 years before the global onset of the Younger Dryas. Underwater, the deposits of methane clathrate - methane frozen into ice - remained stable throughout the Younger Dryas, including during the rapid warming as it ended. As the Northern Hemisphere cooled and the Southern Hemisphere warmed,
3264-536: The Siskiyou Mountains suggests a lag in timing of the Younger Dryas, indicating a greater influence of warmer Pacific conditions on that range. Effects in the Rocky Mountain region were varied. Several sites show little to no changes in vegetation. In the northern Rockies, a significant increase in pines and firs suggests warmer conditions than before and a shift to subalpine parkland in places. That
3360-915: The Swiss Alps and the Dinaric Alps in the Balkans , northern ranges of North America's Rocky Mountains , Two Creeks Buried Forest in Wisconsin and western parts of the New York State , and in the Pacific Northwest, including the Cascade Range . The entire Laurentide ice sheet had advanced between west Lake Superior and southeast Quebec , leaving behind a layer of rock debris ( moraine ) dated to this period. Southeastern Alaska appears to have escaped glaciation; speleothem calcite deposition continued in
3456-570: The Vale of Glamorgan . The Welsh Assembly Government is aware of this, and helped by government initiatives and local actions, opportunities for farmers to diversify have emerged. These include farm tourism, rural crafts, specialist food shops, farmers' markets and added-value food products. In 2015, in an attempt to boost the local economy, Carmarthenshire County Council produced a fifteen-year plan that highlighted six projects which it hoped would create five thousand new jobs. The sectors involved would be in
3552-800: The WWT Llanelli Wetlands Centre and the Carmel National Nature Reserve . There are large stretches of golden sands and the Wales Coast Path now provides a continuous walking route around the whole of Wales. The National Botanic Garden of Wales displays plants from Wales and from all around the world, and the Carmarthenshire County Museum , the National Wool Museum , the Parc Howard Museum ,
3648-481: The boreal forests shifted north. Along the southern margins of the Great Lakes, spruce dropped rapidly, while pine increased, and herbaceous prairie vegetation decreased in abundance, but increased west of the region. The central Appalachian Mountains remained forested during the Younger Dryas, but they were covered in spruce and tamarack boreal forests, switching to temperate broadleaf and mixed forests during
3744-624: The thermal equator would have shifted to the south. Because trade winds from either hemisphere cancel each other out above the thermal equator in a calm, heavily clouded area known as the Intertropical Convergence Zone (ITCZ), a change in its position affects wind patterns elsewhere. For instance, in East Africa , the sediments of Lake Tanganyika were mixed less strongly during this period, indicating weaker wind systems in this area. Shifts in atmospheric patterns are believed to be
3840-541: The "creative industries, tourism, agri-food, advanced manufacturing, energy and environment, and financial and professional services". Under the Local Government Act 1888 , Carmarthenshire became an administrative county with a county council taking over functions from the Quarter Sessions . Under the Local Government Act 1972 , the administrative county of Carmarthenshire was abolished on 1 April 1974 and
3936-619: The 2021 census, showed further decrease, to 39.9% Welsh speakers—the largest percentage drop in all of Wales. With its strategic location and history, the county is rich in archaeological remains such as forts, earthworks and standing stones. Carn Goch is one of the most impressive Iron Age forts and stands on a hilltop near Llandeilo. The Bronze Age is represented by chambered cairns and standing stones on Mynydd Llangyndeyrn , near Llangyndeyrn . Castles that can be easily accessed include Carreg Cennen , Dinefwr , Kidwelly , Laugharne , Llansteffan and Newcastle Emlyn Castle . There are
Afon Cennen - Misplaced Pages Continue
4032-430: The AMOC on timescales of decades or centuries. The Younger Dryas is the best known and best understood because it is the most recent, but it is fundamentally similar to the previous cold phases over the past 120,000 years. This similarity makes the impact hypothesis very unlikely, and it may also contradict the Lake Agassiz hypothesis. On the other hand, some research links volcanism with D–O events, potentially supporting
4128-416: The AMOC. Once the Younger Dryas began, lowered temperatures would have elevated snowfall across the Northern Hemisphere, increasing the ice-albedo feedback . Further, melting snow would be more likely to flood back into the North Atlantic than rainfall would, as less water would be absorbed into the frozen ground. Other modelling shows that sea ice in the Arctic Ocean could have been tens of meters thick by
4224-409: The Holocene. Conversely, pollen and macrofossil evidence from near Lake Ontario indicates that cool, boreal forests persisted into the early Holocene. An increase of pine pollen indicates cooler winters within the central Cascades. Speleothems from the Oregon Caves National Monument and Preserve in southern Oregon 's Klamath Mountains yield evidence of climatic cooling contemporaneous to
4320-444: The Marine Isotope Stage 6, ~130,000 years BP), III (the end of Marine Isotope Stage 8, ~243,000 years BP) and Termination IV (the end of Marine Isotope Stage 10, ~337,000 years BP. When combined with additional evidence from ice cores and paleobotanical data, some have argued that YD-like events inevitably occur during every deglaciation. The 2004 film, The Day After Tomorrow depicts catastrophic climatic effects following
4416-400: The Northern Hemisphere, the length of the growing season declined. Land ice cover experienced little net change, but sea ice extent had increased, contributing to ice–albedo feedback . This increase in albedo was the main reason for net global cooling of 0.6 °C (1.1 °F). During the preceding period, the Bølling–Allerød Interstadial , rapid warming in the Northern Hemisphere
4512-485: The Senedd since 2021 being: In the UK Parliament , the county covers two UK Parliament constituencies in Wales , with its Members of Parliament since 2024 being: Prior to the Industrial Revolution , Carmarthen and Wrexham were the two most populous towns in Wales. In 1931, the county's population was 171,445 and in 1951, 164,800. At the census in 2011, Carmarthenshire had a population of 183,777. Population levels have thus dipped and then increased again over
4608-431: The Younger Dryas with a significant reduction or shutdown of the thermohaline circulation , which circulates warm tropical waters northward through the Atlantic meridional overturning circulation (AMOC). This is consistent with climate model simulations, as well as a range of proxy evidence, such as the decreased ventilation (exposure to oxygen from the surface) of the lowest layers of North Atlantic water. Cores from
4704-403: The Younger Dryas. On the Olympic Peninsula, a mid-elevation site recorded a decrease in fire, but forest persisted and erosion increased during the Younger Dryas, which suggests cool and wet conditions. Speleothem records indicate an increase in precipitation in southern Oregon, the timing of which coincides with increased sizes of pluvial lakes in the northern Great Basin. Pollen record from
4800-467: The amount of dust blown by wind had also increased. Other areas became wetter including northern China (possibly excepting the Shanxi region) The Younger Dryas was initially discovered around the start of the 20th century, through paleobotanical and lithostratigraphic studies of Swedish and Danish bog and lake sites, particularly the Allerød clay pit in Denmark. The analysis of fossilized pollen had consistently shown how Dryas octopetala ,
4896-449: The area and forced the sedentary early Natufian population into a more mobile subsistence pattern. Further climatic deterioration is thought to have brought about cereal cultivation. While relative consensus exists regarding the role of the Younger Dryas in the changing subsistence patterns during the Natufian, its connection to the beginning of agriculture at the end of the period is still being debated. The scientific consensus links
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#17328772411614992-426: The area of Carmarthenshire became three districts within the new county of Dyfed : Carmarthen , Dinefwr and Llanelli . Until 1974, Carmarthenshire had been governed locally by civil parishes ; these in large part equated to ecclesiastical parishes , most of which still exist as part of the Church in Wales. Under the Local Government (Wales) Act 1994 , Dyfed was abolished on 1 April 1996 and Carmarthenshire
5088-415: The cause, and joined the Royalists . In 1648, Carmarthen Castle was recaptured by the Parliamentarians, and Oliver Cromwell ordered it to be slighted. The first industrial canal in Wales was built in 1768 to convey coal from the Gwendraeth Valley to the coast, and the following year, the earliest tramroad bridge was on the tramroad built alongside the canal. During the Napoleonic Wars (1799–1815) there
5184-430: The coastal waters. It was originally hypothesized that the massive outburst from paleohistorical Lake Agassiz had flooded the North Atlantic via the Saint Lawrence Seaway , but little geological evidence had been found. For instance, the salinity in the Saint Lawrence Seaway did not decline, as would have been expected from massive quantities of meltwater. More recent research instead shows that floodwaters followed
5280-581: The continental interior. The Southeastern United States became warmer and wetter than before. There was warming in and around the Caribbean Sea , and in West Africa . It was once believed that the Younger Dryas cooling started at around the same time across the Northern Hemisphere. However, varve (sedimentary rock) analysis carried out in 2015 suggested that the cooling proceeded in two stages: first along latitude 56–54°N, 12,900–13,100 years ago, and then further north, 12,600–12,750 years ago. Evidence from Lake Suigetsu cores in Japan and
5376-425: The cooling to the impact of a disintegrating comet or asteroid. Because there is no impact crater dating to the Younger Dryas period, the proponents usually suggest the impact had struck the Laurentide ice sheet , so that the crater would have disappeared when the ice sheet melted during the Holocene, or that it was an airburst, which would only leave micro- and nanoparticles behind as evidence. Most experts reject
5472-597: The course of eighty years. The population density in Carmarthenshire is 0.8 persons per hectare compared to 1.5 per hectare in Wales as a whole. Carmarthenshire was the most populous of the five historic counties of Wales to remain majority Welsh-speaking throughout the 20th century. According to the 1911 Census , 84.9 per cent of the county's population were Welsh-speaking (compared with 43.5 per cent in all of Wales), with 20.5 per cent of Carmarthenshire's overall population being monolingual Welsh-speakers. In 1931, 82.3 per cent could speak Welsh and in 1951, 75.2 per cent. By
5568-404: The date of the eruption back to 13,006 years BP, or over a century before the Younger Dryas began. This analysis was also challenged in 2023, with some researchers suggesting that the radiocarbon analysis was tainted by magmatic carbon dioxide. For now, the debate continues without a conclusive proof or rejection of the volcanic hypothesis. The Younger Dryas impact hypothesis (YDIH) attributes
5664-488: The east side of Carmarthen Bay . The coastline includes notable beaches such as Pendine Sands and Cefn Sidan sands, and large areas of foreshore are uncovered at low tide along the Loughor and Towy estuaries. The principal towns in the county are Ammanford , Burry Port , Carmarthen , Kidwelly , Llanelli , Llandeilo , Newcastle Emlyn , Llandovery , St Clears , and Whitland . The principal industries are agriculture, forestry, fishing and tourism. Although Llanelli
5760-415: The eastern and central areas. While the Pacific Northwest region cooled by 2–3 °C (3.6–5.4 °F), cooling in western North America was generally less intense. While the Orca Basin in the Gulf of Mexico still experienced a drop in sea surface temperature of 2.4 ± 0.6°C, land areas closer to it, such as Texas , the Grand Canyon area and New Mexico , ultimately did not cool as much as
5856-437: The exception was in tropical Atlantic areas such as Costa Rica , where temperature change was similar to Greenland's. The Holocene warming then proceeded across the globe, following an increase in carbon dioxide levels during the YD period (from ~210 ppm to ~275 ppm ). Younger Dryas cooling was often accompanied by glacier advance and lowering of the regional snow line , with evidence found in areas such as Scandinavia,
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#17328772411615952-422: The glaciers retreat, and it drops if glaciers grow. Altogether, there appears to have been little change in sea level throughout the Younger Dryas. This is in contrast to rapid increases before and after, such as the Meltwater Pulse 1A . On the coasts, glacier advance and retreat also affects relative sea level . Western Norway experienced a relative sea level rise of 10 m ( 32 + 2 ⁄ 3 ft) as
6048-482: The hypothesis, and argue that all of the microparticles are adequately explained by the terrestrial processes. For instance, mineral inclusions from YD-period sediments in Hall's Cave, Texas, have been interpreted by YDIH proponents as extraterrestrial in origin, but a paper published in 2020 argues that they are more likely to be volcanic. Opponents argue that there is no evidence for massive wildfires which would have been caused by an airburst of sufficient size to affect
6144-417: The lack of sea level rise during this period, so other theories have also emerged. An extraterrestrial impact into the Laurentide ice sheet (where it would have left no impact crater) was proposed as an explanation, but this hypothesis has numerous issues and no support from mainstream science. A volcanic eruption as an initial trigger for cooling and sea ice growth has been proposed more recently, and
6240-410: The lack of sea level rise during the Younger Dryas onset by connecting it with a volcanic eruption. Eruptions often deposit large quantities of sulfur dioxide particles in the atmosphere, where they are known as aerosols , and can have a large cooling effect by reflecting sunlight. This phenomenon can also be caused by anthropogenic sulfur pollution, where it is known as global dimming . Cooling from
6336-432: The last and the strongest of these events. However, there is some debate over what caused the AMOC to become so weak in the first place. The hypothesis historically most supported by scientists was an interruption from an influx of fresh, cold water from North America's Lake Agassiz into the Atlantic Ocean. While there is evidence of meltwater travelling via the Mackenzie River , this hypothesis may not be consistent with
6432-466: The low profitability of the livestock sector. Carmarthenshire, as a tourist destination, offers a wide range of outdoor activities. Much of the coast is fairly flat; it includes the Millennium Coastal Park , which extends for 10 miles (16 km) to the west of Llanelli; the National Wetlands Centre ; a championship golf course; and the harbours of Burry Port and Pembrey . The sandy beaches at Llansteffan and Pendine are further west. Carmarthenshire has
6528-426: The main reason why Northern Hemisphere summers generally did not cool during the Younger Dryas. Since winds carry moisture in the form of clouds, these changes also affect precipitation . Thus, evidence from the pollen record shows that some areas have become very arid, including Scotland, the North American Midwest , Anatolia and southern China . As North Africa, including the Sahara Desert , became drier,
6624-415: The more agricultural part of the county still hold regular markets where livestock is traded. In the north of the county, in and around the Teifi Valley, there was a thriving woollen industry in the nineteenth and early twentieth centuries. Here water-power provided the energy to drive the looms and other machinery at the mills . The village of Dre-fach Felindre at one time contained twenty-four mills and
6720-455: The most abrupt climatic changes during the YD. Climate models also indicate that a single freshwater outburst, no matter how large, would not have been able to weaken the AMOC for over 1,000 years, as required by the Younger Dryas timeline, unless other factors were also involved. Some modelling explains this by showing that the melting of Laurentide Ice Sheet led to greater rainfall over the Atlantic Ocean, freshening it and so helping to weaken
6816-438: The north across the valley of the River Towy . The south coast contains many fishing villages and sandy beaches. The highest point ( county top ) is the minor summit of Fan Foel , height 781 metres (2,562 ft), which is a subsidiary top of the higher mountain of Fan Brycheiniog , height 802.5 metres (2,633 ft) (the higher summit, as its name suggests, is actually across the border in Brecknockshire/Powys). Carmarthenshire
6912-576: The onset of the Younger Dryas event. It has been suggested that this eruption would have been stronger than any during the Common Era , some of which have been able to cause several decades of cooling. According to 1990s research, the Laacher See eruption (present-day volcanic lake in Rhineland-Palatinate , Germany ) would have matched the criteria, but radiocarbon dating done in 2021 pushes
7008-408: The onset of the Younger Dryas, so that it would have been able to shed icebergs into the North Atlantic, which would have been able to weaken the circulation consistently. Notably, changes in sea ice cover would have had no impact on sea levels, which is consistent with the absence of significant sea level rise during the Younger Dryas, and particularly during its onset. Some scientists also explain
7104-463: The opposite happens when it is weak. The scientific consensus is that severe AMOC weakening explains the climatic effects of the Younger Dryas. It also explains why the Holocene warming had proceeded so rapidly once the AMOC change was no longer counteracting the increase in carbon dioxide levels. AMOC weakening causing polar seesaw effects is also consistent with the accepted explanation for Dansgaard–Oeschger events , with YD likely to have been
7200-481: The presence of anomalously high levels of volcanism immediately preceding the onset of the Younger Dryas has been confirmed in both ice cores and cave deposits. The Younger Dryas is named after the alpine – tundra wildflower Dryas octopetala , because its fossils are abundant in the European (particularly Scandinavian ) sediments dating to this timeframe. The two earlier geologic time intervals where this flower
7296-606: The present title in 2013. Scarlets is the regional professional rugby union team that plays in the Pro14 , they play their home matches at their ground, Parc y Scarlets . Honours include winning the 2003/04 and 2016/17 Pro12. Llanelli RFC is a semi-professional rugby union team that play in the Welsh Premier Division , also playing home matches at Parc y Scarlets . Among many honours, they have been WRU Challenge Cup winners on fourteen occasions and frequently taken part in
7392-454: The region despite being retarded, indicating the absence of permafrost and glaciation. On the other hand, the warming of the Southern Hemisphere led to ice loss in Antarctica, South America and New Zealand. Moreover, while Greenland as a whole had cooled, glaciers had only grown in the north of the island, and they had retreated from the rest of Greenland's coasts. This was likely driven by
7488-563: The ruinous remains of Talley Abbey , and the coastal village of Laugharne is for ever associated with Dylan Thomas . Stately homes in the county include Aberglasney House and Gardens , Golden Grove and Newton House . There are plenty of opportunities in the county for hiking, observing wildlife and admiring the scenery. These include Brechfa Forest , the Pembrey Country Park , the Millennium Coastal Park at Llanelli,
7584-551: The southeastern part which was once heavily industrialised with coal mining, steel-making and tin-plating. In the north of the county, the woollen industry was very important in the 18th century. The economy depends on agriculture, forestry, fishing and tourism. West Wales was identified in 2014 as the worst-performing region in the United Kingdom along with the South Wales Valleys with the decline in its industrial base, and
7680-412: The start of the 21st century. Strong cooling of around 2–6 °C (3.6–10.8 °F) had also taken place in Europe. Icefields and glaciers formed in upland areas of Great Britain , while many lowland areas developed permafrost , implying a cooling of −5 °C (23 °F) and a mean annual temperature no higher than −1 °C (30 °F). North America also became colder, particularly in
7776-544: The strengthened Irminger Current . The Jabllanica mountain range in the Balkans also experienced ice loss and glacial retreat: this was likely caused by the drop in annual precipitation, which would have otherwise frozen and helped to maintain the glaciers. Unlike now, the glaciers were still present in northern Scotland , but they had thinned during the Younger Dryas. The amount of water contained within glaciers directly influences global sea levels - sea level rise occurs if
7872-498: The summer. An exception appears to have taken place in what is now Maine , where winter temperatures remained stable, yet summer temperatures decreased by up to 7.5 °C (13.5 °F). While the Northern Hemisphere cooled, considerable warming occurred in the Southern Hemisphere. Sea surface temperatures were warmer by 0.3–1.9 °C (0.54–3.42 °F), and Antarctica , South America (south of Venezuela ) and New Zealand all experienced warming. The net temperature change
7968-408: The thermohaline circulation, mineralogical and geochemical evidence or for simultaneous human population declines and mass animal extinctions which would have been required by this hypothesis. Statistical analysis shows that the Younger Dryas is merely the last of 25 or 26 Dansgaard–Oeschger events (D–O events) over the past 120,000 years. These episodes are characterized by abrupt changes in
8064-451: The tropics, the cooling was spread out over several centuries, and the same was true of the early-Holocene warming. Even in the Northern Hemisphere, temperature change was highly seasonal, with much colder winters, cooler springs, yet no change or even slight warming during the summer. Substantial changes in precipitation also took place, with cooler areas experiencing substantially lower rainfall, while warmer areas received more of it. In
8160-401: The twentieth century. Agriculture and forestry are the main sources of income over most of the county of Carmarthenshire. On improved pastures, dairying is important and in the past, the presence of the railway enabled milk to be transported to the urban areas of England. The creamery at Whitland is now closed but milk processing still takes place at Newcastle Emlyn where mozzarella cheese
8256-534: The volcanic hypothesis. Events similar to the Younger Dryas appear to have occurred during the other terminations - a term used to describe a comparatively rapid transition from cold glacial conditions to warm interglacials. The analysis of lake and marine sediments can reconstruct past temperatures from the presence or absence of certain lipids and long chain alkenones , as these molecules are very sensitive to temperature. This analysis provides evidence for YD-like events during Termination II (the end of
8352-547: The western subtropical North Atlantic show that the "bottom water" lingered there for 1,000 years, twice the age of Late Holocene bottom waters from the same site around 1,500 BP. Further, the otherwise anomalous warming of the southeastern United States matches the hypothesis that as the AMOC weakened and transported less heat from the Caribbean towards Europe through the North Atlantic Gyre , more of it would stay trapped in
8448-622: The young men. Carmarthen was particularly susceptible to plague as it was brought in by flea-infested rats on board ships from southern France. In 1405, Owain Glyndŵr captured Carmarthen Castle and several other strongholds in the neighbourhood. However, when his support dwindled, the principal men of the county returned their allegiance to King Henry V . During the English Civil War , Parliamentary forces under Colonel Roland Laugharne besieged and captured Carmarthen Castle but later abandoned
8544-603: Was a relatively modest cooling of 0.6 °C (1.1 °F). Temperature changes of the Younger Dryas lasted 1,150–1,300 years. According to the International Commission on Stratigraphy , the Younger Dryas ended around 11,700 years ago, although some research places it closer to 11,550 years ago. The end of Younger Dryas was also abrupt: in previously cooled areas, warming to previous levels took place over 50–60 years. The tropics experienced more gradual temperature recovery over several centuries;
8640-686: Was abundant in Europe are the Oldest Dryas (approx. 18,500-14,000 BP) and Older Dryas (~14,050–13,900 BP), respectively. On the contrary, Dryas octopetala was rare during the Bølling–Allerød Interstadial . Instead, European temperatures were warm enough to support trees in Scandinavia, as seen at the Bølling and Allerød sites in Denmark . In Ireland , the Younger Dryas has also been known as
8736-525: Was disputed between the Normans and the Welsh lords and many of the castles built around this time, first of wood and then stone, changed hands several times. Following the Conquest of Wales by Edward I , the region was reorganized by the Statute of Rhuddlan in 1284 into Carmarthenshire. Edward I made Carmarthen the capital of this new county, establishing his courts of chancery and his exchequer there, and holding
8832-511: Was increased demand for coal, iron and agricultural goods, and the county prospered. The landscape changed as much woodland was cleared to make way for more food production, and mills, power stations, mines and factories sprang up between Llanelli and Pembrey . Carmarthenshire was at the centre of the Rebecca Riots around 1840, when local farmers and agricultural workers dressed as women and rebelled against higher taxes and tolls. The county
8928-467: Was known as the "Huddersfield of Wales". The demand for woollen cloth declined in the twentieth century and so did the industry. In 2014, West Wales was identified as the worst-performing region in the United Kingdom along with the South Wales Valleys. The gross value added economic indicator showed a figure of £14,763 per head in these regions, as compared with a GVA of £22,986 for Cardiff and
9024-509: Was offset by the equivalent cooling in the Southern Hemisphere. This "polar seesaw" pattern is consistent with changes in thermohaline circulation (particularly the Atlantic meridional overturning circulation or AMOC), which greatly affects how much heat is able to go from the Southern Hemisphere to the North. The Southern Hemisphere cools and the Northern Hemisphere warms when the AMOC is strong, and
9120-514: Was part of the Kingdom of Deheubarth in the High Middle Ages . After invasion by the Normans in the 12th and 13th centuries it was subjugated , along with other parts of Wales, by Edward I of England . There was further unrest in the early 15th century, when the Welsh rebelled under Owain Glyndŵr , and during the English Civil War . Carmarthenshire is mainly an agricultural county, apart from
9216-471: Was re-established as a county. The three districts united to form a unitary authority which had the same boundaries as the traditional county of Carmarthenshire. In 2003, the Clynderwen community council area was transferred to the administrative county of Pembrokeshire . As of 2024, the council leader is Darren Price of Plaid Cymru . The county covers three Senedd constituencies , with its Members of
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