Wedde ( Dutch pronunciation: [ˈʋɛdə] ) is a village in the municipality Westerwolde in the province Groningen in the Netherlands . It is located 9 km southeast of Winschoten . The castle Wedderborg is located in the village.
95-537: Most of Westerwolde was a raised bog with few inhabitants, however it formed a natural border between Groningen , East Frisia and the Prince-Bishopric of Münster , and therefore changed ownership many times during its history. Wedde was located on the road between Groningen and Germany, and dates from the 12th century. The Westerwoldsche Aa [ nl ] flows through the village. In 1316, Westerwolde became part of Münster. In 1362, Egge I Addinga
190-732: A broad trend of very gradual cooling known as Neoglaciation , which lasted from the end of the HCO to before the Industrial Revolution . From the 10th-14th century, the climate was similar to that of modern times during a period known as the Mediaeval Warm Period (MWP), also known as the Mediaeval Climatic Optimum (MCO). It was found that the warming that is taking place in current years is both more frequent and more spatially homogeneous than what
285-415: A distinction is made between lake mires or 'siltation-formed raised bogs' ( Verlandungshochmoore ) and 'mire-formed raised bogs' ( wurzelechte Hochmoore ). The former emerged in a secondary process after the silting up of lakes or oxbows (see illustration on the right in the sequence). At first, fens emerged under the influence of groundwater ( minerotrophy ). Oxygen deficiencies and high acidity in
380-604: A larger effect on the mid-to-low latitudes and mid-to-high latitudes after ~5600 B.P. Human activity through land use changes already by the Mesolithic had major ecological impacts; it was an important influence on Holocene climatic changes, and is believed to be why the Holocene is an atypical interglacial that has not experienced significant cooling over its course. From the start of the Industrial Revolution onwards, large-scale anthropogenic greenhouse gas emissions caused
475-564: A marine transgression occurred in southeastern Africa; in the Lake Lungué basin, this sea level highstand occurred from 740 to 910 AD, or from 1,210 to 1,040 BP, as evidenced by the lake's connection to the Indian Ocean at this time. This transgression was followed by a period of transition that lasted until 590 BP, when the region experienced significant aridification and began to be extensively used by humans for livestock herding. In
570-524: A moist, balanced climate in which to grow. The quantity of precipitation has to be greater than the water losses through discharge and evaporation. In addition, the precipitation must be evenly spread through the year. Raised bogs in Europe have been developing for about 11,000 years, since the beginning of the Holocene and after the retreat of the last ice sheet . As far as their origins are concerned,
665-650: A more sustainable sedentary lifestyle . This form of lifestyle change allowed humans to develop towns and villages in centralized locations, which gave rise to the world known today. It is believed that the domestication of plants and animals began in the early part of the Holocene in the tropical areas of the planet. Because these areas had warm, moist temperatures, the climate was perfect for effective farming. Culture development and human population change, specifically in South America, has also been linked to spikes in hydroclimate resulting in climate variability in
760-584: A much wetter climate from 11,400 to 11,100 BP due to intensification of the ISM. Over the Early Holocene, the region was very wet, but during the Middle Holocene from 6,200 to 3,900 BP, aridification occurred, with the subsequent Late Holocene being relatively arid as a whole. Coastal southwestern India experienced a stronger ISM from 9,690 to 7,560 BP, during the HCO. From 3,510 to 2,550 BP, during
855-535: A near unanimous vote, the rejection of the working group's Anthropocene Epoch proposal for inclusion in the Geologic Time Scale. The Holocene is a geologic epoch that follows directly after the Pleistocene . Continental motions due to plate tectonics are less than a kilometre over a span of only 10,000 years. However, ice melt caused world sea levels to rise about 35 m (115 ft) in
950-608: A negative excursion in the δ O record lasting 400 years, is the most prominent climatic event occurring in the Holocene Epoch, and may have marked a resurgence of ice cover. It has been suggested that this event was caused by the final drainage of Lake Agassiz , which had been confined by the glaciers, disrupting the thermohaline circulation of the Atlantic . This disruption was the result of an ice dam over Hudson Bay collapsing sending cold lake Agassiz water into
1045-457: A raised bog on neighbouring mineral soil. The formation of a typical raised bog is a very slow process, which lasts from centuries to a thousand years even in favourable, undisturbed conditions. Furthermore, there are a number of transitional and intermediate bogs , which in different ways combine characteristics of both raised bogs and fens. (See bog .) The main constituents of the peat are rootless peat mosses that grow slowly in height whilst at
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#17328012091731140-542: A result of freeze-thaw processes of the surrounding water. The low temperatures prevent full decomposition of the organic material. Polygonal bogs ( Polygonmoore ) are widespread on the Arctic and sub-Arctic plains of Siberia and North America and cover vast areas. They are associated with patterned peatland and ice wedges . A scanty layer of peat-forming vegetation can occur in the inner honeycomb-shaped areas of this frost pattern terrain ( cryoturbation ) and are fed during
1235-475: A role. Drangajökull, Iceland's northernmost glacier, melted shortly after 9,200 BP. In Northern Germany , the Middle Holocene saw a drastic increase in the amount of raised bogs, most likely related to sea level rise. Although human activity affected geomorphology and landscape evolution in Northern Germany throughout the Holocene, it only became a dominant influence in the last four centuries. In
1330-498: Is a contraction of Bellingwolde and Wedde . In 2018, it became part of the new municipality of Westerwolde . Geselberg (literally: Scourge Mountain) is a hill near Wedde. Between 1587 and 1597, witch trials were held at Wedderborg, and 21 women and 1 man were burned at the stake at Geselberg. In 1597, witch trials were outlawed in the Dutch Republic, and Geselberg was only used for hangings and flagellation . Wedde
1425-464: Is a succession of raised bog types along the line of descent towards the ocean, from northwest to southeast. As a result of peat use, raised bogs have been harvested for peat and cultivated, apart from a few remnants (less than 10% of the original area). The largest contiguous raised bog in central Europe was the Bourtange Moor , which originally covered an area of about 2,300 km including
1520-634: Is located centeṛ̣ west of the municipality Westerwolde , in the east of the province Groningen , in the northeast of the Netherlands . Wedde is an administrative neighbourhood ( Dutch : buurt ) in the district (Dutch: wijk ) of Blijham . Raised bog Raised bogs , also called ombrotrophic bogs , are acidic, wet habitats that are poor in mineral salts and are home to flora and fauna that can cope with such extreme conditions. Raised bogs, unlike fens , are exclusively fed by precipitation ( ombrotrophy ) and from mineral salts introduced from
1615-411: Is low in salt. By contrast, mire-formed raised bogs are created directly on the mineral substrate of low-salt areas without having been initially formed as fens (see figure on the left in the sequence). They are formed either as a primary bog due to the erosion of previously dry mineral soils, for example due to clearing, climate change or infiltration, or as a secondary process as a result of the growth of
1710-459: Is not yet clear how these bogs have emerged as mosses are entirely absent here. Coastal bogs ( Planregenmoore ) or Atlantic bogs, as their names suggest, tend to form close to the sea. In addition, in regions covered by blanket bog, there are also lightly convex coastal bogs with low energy surface relief in level locations. The distribution of coastal bogs in Europe extends from Ireland to the east via South Norway to Southwest Sweden and north to
1805-428: Is strongly decomposed, and an overlying white peat layer which is less decomposed. This difference is a result of changes in the hydrology of the bog. The white peat grew more rapidly under humid conditions than the black peat. This is attributed to a climate change with high precipitation and low evaporation around 1000 to 500 BC. As a result, the peat moss growth grew locally and the black peat/white peat boundary layer
1900-504: Is used for all the seven epochs of the Cenozoic Era. The International Commission on Stratigraphy has defined the Holocene as starting approximately 11,700 years before 2000 CE (11,650 cal years BP , or 9,700 BCE). The Subcommission on Quaternary Stratigraphy (SQS) regards the term 'recent' as an incorrect way of referring to the Holocene, preferring the term 'modern' instead to describe current processes. It also observes that
1995-634: The Amazon Basin . In these regions, bogs of all kinds and peat deposits of four million square kilometres have been formed, covering three percent of the Earth's surface. In the southern hemisphere low-mineral-rich bogs are rarely formed from peat mosses. Only in the Tierra del Fuego do peat moss raised bogs exist. The most peaty countries in the tropics are found in Southeast Asia. In many cases it
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#17328012091732090-599: The Annex 1 habitats : active raised bog, turlough (both priority habitats), degraded raised bog (capable of regeneration) and vegetation of depressions (rhynchosporion). These habitats are considered to be among the best examples in Ireland due to their relatively large size and the generally low levels of disturbance. In the Natura form compiled for the site active raised bog was given a rating of A (Excellent value) which emphasises
2185-637: The Black Forest the Wildseemoor has been protected and, in the Vosges on le Tanet , north of the Col de la Schlucht a large area has been protected. The Alpine Foreland , which was formed by ice-age glaciation, is also rich in peatland. The Wurzacher Ried (Haidgauer Regenmoorschild) is considered the largest and best preserved raised bog in central Europe. Other raised bogs and peatland areas include
2280-734: The Federsee , the High Fens on the Germano-Belgian border, the Ewiges Meer near Aurich and the Lengener Meer near Wiesmoor. In 2003, Estonia exported 3.6 million m³ of peat for west European garden use, more than 60% of the state production. In Lithuania 60% of the usable peat area has been prepared for extraction or is already exhausted. Lough Lurgeen Bog and Glenamaddy Turlough Bog contains very good examples of
2375-629: The French Alps , geochemistry and lithium isotope signatures in lake sediments have suggested gradual soil formation from the Last Glacial Period to the Holocene climatic optimum , and this soil development was altered by the settlement of human societies. Early anthropogenic activities such as deforestation and agriculture reinforced soil erosion, which peaked in the Middle Ages at an unprecedented level, marking human forcing as
2470-552: The International Commission on Stratigraphy (ICS) had a working group to determine whether it should be. In May 2019, members of the working group voted in favour of recognizing the Anthropocene as formal chrono-stratigraphic unit, with stratigraphic signals around the mid-twentieth century CE as its base. The exact criteria was still to be determined, after which the recommendation also had to be approved by
2565-625: The Intertropical Convergence Zone (ITCZ) produced increased monsoon rainfall over North Africa. The lush vegetation of the Sahara brought an increase in pastoralism . The AHP ended around 5,500 BP, after which the Sahara began to dry and become the desert it is today. A stronger East African Monsoon during the Middle Holocene increased precipitation in East Africa and raised lake levels. Around 800 AD, or 1,150 BP,
2660-738: The Kalahari Desert , Holocene climate was overall very stable and environmental change was of low amplitude. Relatively cool conditions have prevailed since 4,000 BP. In the Middle East, the Holocene brought a warmer and wetter climate, in contrast to the preceding cold, dry Younger Dryas . The Early Holocene saw the advent and spread of agriculture in the Fertile Crescent — sheep , goat , cattle , and later pig were domesticated, as well as cereals, like wheat and barley , and legumes —which would later disperse into much of
2755-768: The Llanquihue in Chile and the Otiran in New Zealand. The Holocene can be subdivided into five time intervals, or chronozones , based on climatic fluctuations: Geologists working in different regions are studying sea levels, peat bogs, and ice-core samples, using a variety of methods, with a view toward further verifying and refining the Blytt–Sernander sequence . This is a classification of climatic periods initially defined by plant remains in peat mosses . Though
2850-590: The Lofoten . In North America there are coastal bogs in the area of the Great Lakes (especially in Minnesota and Ontario ). Coastal bogs are also fed exclusively by rain. In the less oceanically influenced climatic regions of North-West Europe (lower precipitation), raised bogs take on the classical lens shape and are called plateau bogs or plateau raised bogs ( Plateauregenmoore ). They grow more strongly in
2945-650: The North Atlantic ocean . Furthermore, studies show that the melting of Lake Agassiz led to sea-level rise which flooded the North American coastal landscape. The basal peat plant was then used to determine the resulting local sea-level rise of 0.20-0.56m in the Mississippi Delta . Subsequent research, however, suggested that the discharge was probably superimposed upon a longer episode of cooler climate lasting up to 600 years and observed that
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3040-690: The Quaternary period. The Holocene is an interglacial period within the ongoing glacial cycles of the Quaternary, and is equivalent to Marine Isotope Stage 1 . The Holocene correlates with the last maximum axial tilt of the Earth towards the Sun, and corresponds with the rapid proliferation, growth, and impacts of the human species worldwide, including all of its written history , technological revolutions , development of major civilizations , and overall significant transition towards urban living in
3135-581: The Tien Shan , sedimentological evidence from Swan Lake suggests the period between 8,500 and 6,900 BP was relatively warm, with steppe meadow vegetation being predominant. An increase in Cyperaceae from 6,900 to 2,600 BP indicates cooling and humidification of the Tian Shan climate that was interrupted by a warm period between 5,500 and 4,500 BP. After 2,600 BP, an alpine steppe climate prevailed across
3230-535: The sixth mass extinction or Anthropocene extinction , is an ongoing extinction event of species during the present Holocene epoch (with the more recent time sometimes called Anthropocene) as a result of human activity . The included extinctions span numerous families of fungi , plants , and animals , including mammals , birds , reptiles , amphibians , fish and invertebrates . With widespread degradation of highly biodiverse habitats such as coral reefs and rainforests , as well as other areas,
3325-957: The Dutch portion, but only small sections remain. The largest remaining raised bog in northern Europe is the 76 km Lille Vildmose . Other large raised bogs are the Teufelsmoor northeast of Bremen, the Vehnemoor (exhausted) and the Esterweger Dose (formerly about 80 km , exhausted) between Oldenburg and Papenburg. The raised bogs of the Central Uplands of the Harz , Solling , Thuringian Forest ( Großer Beerberg , Schneekopf - Teufelsbad, Fichtenkopf, Saukopf), Giant Mountains , Ore Mountains , Fichtel and Rhön ( Black Moor , Red Moor ) are, by contrast, comparatively small. In
3420-616: The Earth to warm. Likewise, climatic changes have induced substantial changes in human civilisation over the course of the Holocene. During the transition from the last glacial to the Holocene, the Huelmo–Mascardi Cold Reversal in the Southern Hemisphere began before the Younger Dryas, and the maximum warmth flowed south to north from 11,000 to 7,000 years ago. It appears that this was influenced by
3515-590: The Holocene Epoch. A 1,500-year cycle corresponding to the North Atlantic oceanic circulation may have had widespread global distribution in the Late Holocene. From 8,500 BP to 6,700 BP, North Atlantic climate oscillations were highly irregular and erratic because of perturbations from substantial ice discharge into the ocean from the collapsing Laurentide Ice Sheet. The Greenland ice core records indicate that climate changes became more regional and had
3610-474: The Holocene has shown significant variability despite ice core records from Greenland suggesting a more stable climate following the preceding ice age. Marine chemical fluxes during the Holocene were lower than during the Younger Dryas, but were still considerable enough to imply notable changes in the climate. The temporal and spatial extent of climate change during the Holocene is an area of considerable uncertainty, with radiative forcing recently proposed to be
3705-480: The Holocene, however, the domestication of plants and animals allowed humans to develop villages and towns in centralized locations. Archaeological data shows that between 10,000 and 7,000 BP rapid domestication of plants and animals took place in tropical and subtropical parts of Asia , Africa , and Central America . The development of farming allowed humans to transition away from hunter-gatherer nomadic cultures, which did not establish permanent settlements, to
3800-437: The Late Holocene, the ISM became weaker, although this weakening was interrupted by an interval of unusually high ISM strength from 3,400 to 3,200 BP. Southwestern China experienced long-term warming during the Early Holocene up until ~7,000 BP. Northern China experienced an abrupt aridification event approximately 4,000 BP. From around 3,500 to 3,000 BP, northeastern China underwent a prolonged cooling, manifesting itself with
3895-476: The Late Holocene. Animal and plant life have not evolved much during the relatively short Holocene, but there have been major shifts in the richness and abundance of plants and animals. A number of large animals including mammoths and mastodons , saber-toothed cats like Smilodon and Homotherium , and giant sloths went extinct in the late Pleistocene and early Holocene. These extinctions can be mostly attributed to people. In America, it coincided with
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3990-458: The Middle Holocene was notable for its warmth, with rhythmic temperature fluctuations every 400-500 and 1,000 years. Before 7,500 BP, the Gulf of Thailand was exposed above sea level and was very arid. A marine transgression occurred from 7,500 to 6,200 BP amidst global warming. During the Middle Holocene, western North America was drier than present, with wetter winters and drier summers. After
4085-642: The Middle to Late Holocene, the coastline of the Levant and Persian Gulf receded, prompting a shift in human settlement patterns following this marine regression. Central Asia experienced glacial-like temperatures until about 8,000 BP, when the Laurentide Ice Sheet collapsed. In Xinjiang , long-term Holocene warming increased meltwater supply during summers, creating large lakes and oases at low altitudes and inducing enhanced moisture recycling. In
4180-474: The Scandinavian hills, central Finland, Karelia and north Siberia. In North America, Alaska is the main location for string bogs, thanks to its cold continental climate. Frost action plays an important role in these bogs. On the ridges or hummocks, ground ice is found until early summer. Palsa bogs ( Palsamoore or Palsenmoore ) are found on the margins of the Arctic permafrost soils ( tundra ). Here
4275-425: The air. They thus represent a special type of bog , hydrologically , ecologically and in terms of their development history, in which the growth of peat mosses over centuries or millennia plays a decisive role. They also differ in character from blanket bogs which are much thinner and occur in wetter, cloudier climatic zones. Raised bogs are very threatened by peat cutting and pollution by mineral salts from
4370-524: The arrival of the Clovis people; this culture was known for " Clovis points " which were fashioned on spears for hunting animals. Shrubs, herbs, and mosses had also changed in relative abundance from the Pleistocene to Holocene, identified by permafrost core samples. Throughout the world, ecosystems in cooler climates that were previously regional have been isolated in higher altitude ecological "islands". The 8.2-ka event , an abrupt cold spell recorded as
4465-434: The bog 'floor'. Here fresh organic substances (peat formation horizon) are created by the growth and dying of plant elements. The "catotelm" (Greek: kato = below) is the underlying water-saturated part with less biological activity. This layer is counted as a geological subsoil due to the small earth-forming processes that are still going on and is known as the peat preservation horizon ( Torferhaltungshorizont ). In raised bogs,
4560-476: The central area of these bogs, there are always large kolks. In northern Russia and western Siberia, kermis frequently occur in giant complexes where the bogs have grown into one another. Kermis are also found in Finland in the central and northern boreal forest zone. String bogs or aapa fens ( Aapamoore or Strangmoore ) are typically found on the northern fringes of the distribution area for raised bogs, in
4655-433: The centre than at the margins. This results in the centre of the bog bulging, hence the name "raised bog". This bulging can be several metres high. As a result, the perimeter of the bog is more or less inclined, and is known as the rand . The sloping bog sides of larger bogs are traversed by drainage channels or soaks ( Rüllen ) through which excess water is discharged. Other characteristic structures of these raised bogs are
4750-509: The classical, lens-shaped bogs of northwest Germany . The bogs are not influenced by mineral-rich groundwater or surface water, but are fed exclusively by precipitation — mainly rainwater, hence their alternative German designation of Regenmoor or "rain-fed bog". Thus the latter refers to all bogs, not just those that are arched or only slightly arched, but which nevertheless are characterized by an extreme mineral salt deficiency and other resulting ecological properties. A living raised bog needs
4845-484: The climate, Greenlandian (11,700 years ago to 8,200 years ago), Northgrippian (8,200 years ago to 4,200 years ago) and Meghalayan (4,200 years ago to the present), as proposed by International Commission on Stratigraphy . The oldest age, the Greenlandian, was characterized by a warming following the preceding ice age. The Northgrippian Age is known for vast cooling due to a disruption in ocean circulations that
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#17328012091734940-433: The constantly moist substrate inhibited the decomposition of dead plant parts and led to peat formation. Thus the raised bog rises very slowly above the groundwater level, hence its name. As the resulting peat slowly rises above the influence of mineral salts in the groundwater, it reaches a point where the development of the raised bog begins to change in nature; that is, the bog now becomes fed solely by rainwater, which
5035-454: The disruption of Bronze Age civilisations in the region. Eastern and southern China, the monsoonal regions of China, were wetter than present in the Early and Middle Holocene. Lake Huguangyan's TOC, δ C wax , δ C org , δ N values suggest the period of peak moisture lasted from 9,200 to 1,800 BP and was attributable to a strong East Asian Summer Monsoon (EASM). Late Holocene cooling events in
5130-473: The early part of the Holocene and another 30 m in the later part of the Holocene. In addition, many areas above about 40 degrees north latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 m (590 ft) due to post-glacial rebound over the late Pleistocene and Holocene, and are still rising today. The sea-level rise and temporary land depression allowed temporary marine incursions into areas that are now far from
5225-427: The end of the last strong phase. Ice core measurements imply that the sea surface temperature (SST) gradient east of New Zealand, across the subtropical front (STF), was around 2 degrees Celsius during the HCO. This temperature gradient is significantly less than modern times, which is around 6 degrees Celsius. A study utilizing five SST proxies from 37°S to 60°S latitude confirmed that the strong temperature gradient
5320-617: The end of the thermal maximum of the HCO around 4,500 BP, the East Greenland Current underwent strengthening. A massive megadrought occurred from 2,800 to 1,850 BP in the Great Basin . Eastern North America underwent abrupt warming and humidification around 10,500 BP and then declined from 9,300 to 9,100 BP. The region has undergone a long term wettening since 5,500 BP occasionally interrupted by intervals of high aridity. A major cool event lasting from 5,500 to 4,700 BP
5415-485: The entire system is very important from both a hydrological and ecological perspective. A region of peatland extends from Alaska in the west to the coast of the Atlantic in the east, and is comparable in size to that of West Siberia. A zone of domed raised bogs adjoins the zones of palsa bogs and string fens. In the direction of descent towards the ocean, blanket bogs occur east of Hudson Bay. These are superseded towards
5510-596: The extent of the area affected was unclear. The beginning of the Holocene corresponds with the beginning of the Mesolithic age in most of Europe . In regions such as the Middle East and Anatolia , the term Epipaleolithic is preferred in place of Mesolithic, as they refer to approximately the same time period. Cultures in this period include Hamburgian , Federmesser , and the Natufian culture , during which
5605-571: The flat, treeless raised bog core with its characteristic microrelief of shallow wet depressions or flarks ( Schlenken ) alternating with hummocks ( Bülten ) of drier peat moss. Larger accumulations of water in the middle of the bogs are called kolks or bog ponds (of humic acid -rich water); the wet area on the outer margins is known as a moat or lagg . Genuine ombrotrophic bogs on the North German Plain are usually sharply divided into two layers: an underlying black peat layer, which
5700-458: The importance of the site. Raised bog habitats are now very rare in Europe and it has recently been estimated that the Republic of Ireland contains 50% of the relatively intact oceanic raised bog systems in Europe. The site contains the second largest area of intact raised bog surface in Ireland. The combination of raised bog, oligotrophic lake and turlough habitats is unique in Ireland and thus
5795-564: The kermi bog type. They represent probably the most important type of raised bog on earth. The Vasyugan Swamp in this region, is the largest bog system on earth and covers more than 50,000 km (19,000 sq mi). It is estimated to contain over 14 billion tonnes of peat deposits. The largest central European raised bog areas are the southern North Sea coastal area and the Alpine Foreland . As in North America there
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#17328012091735890-423: The last glacial period and then classify climates of more recent prehistory . Paleontologists have not defined any faunal stages for the Holocene. If subdivision is necessary, periods of human technological development, such as the Mesolithic , Neolithic , and Bronze Age , are usually used. However, the time periods referenced by these terms vary with the emergence of those technologies in different parts of
5985-477: The margins of lowland bogs i.e. fens , or transition into them. Kermi bogs ( Kermimoore, Schildhochmoore, Strangmoore or Blankenmoore ) or kermi raised bogs have only a slightly domed shape. The surface of the bog rises steadily from the broad lagg zone. Kermis have ridge-shaped hummocks of peat moss, that are aligned with the contours of the bog. The flarks or elongated depressions are generally tub-shaped and hardly distinguishable externally from kolks . In
6080-411: The method was once thought to be of little interest, based on C dating of peats that was inconsistent with the claimed chronozones, investigators have found a general correspondence across Eurasia and North America . The scheme was defined for Northern Europe , but the climate changes were claimed to occur more widely. The periods of the scheme include a few of the final pre-Holocene oscillations of
6175-531: The mid-19th century. The LIA was the coldest interval of time of the past two millennia. Following the Industrial Revolution, warm decadal intervals became more common relative to before as a consequence of anthropogenic greenhouse gases, resulting in progressive global warming. In the late 20th century, anthropogenic forcing superseded variations in solar activity as the dominant driver of climate change, though solar activity has continued to play
6270-537: The mid-Holocene (8.2 - 4.2 k cal BP). Climate change on seasonality and available moisture also allowed for favorable agricultural conditions which promoted human development for Maya and Tiwanaku regions. In the Korean Peninsula , climatic changes fostered a population boom during the Middle Chulmun period from 5,500 to 5,000 BP, but contributed to a subsequent bust during the Late and Final Chulmun periods, from 5,000 to 4,000 BP and from 4,000 to 3,500 BP respectively. The Holocene extinction , otherwise referred to as
6365-453: The most powerful factor affecting surface processes. The sedimentary record from Aitoliko Lagoon indicates that wet winters locally predominated from 210 to 160 BP, followed by dry winter dominance from 160 to 20 BP. North Africa, dominated by the Sahara Desert in the present, was instead a savanna dotted with large lakes during the Early and Middle Holocene, regionally known as the African Humid Period (AHP). The northward migration of
6460-459: The oldest inhabited places still existing on Earth were first settled, such as Tell es-Sultan (Jericho) in the Middle East . There is also evolving archeological evidence of proto-religion at locations such as Göbekli Tepe , as long ago as the 9th millennium BC . The preceding period of the Late Pleistocene had already brought advancements such as the bow and arrow , creating more efficient forms of hunting and replacing spear throwers . In
6555-539: The origin of cycles identified in the North Atlantic region. Climate cyclicity through the Holocene ( Bond events ) has been observed in or near marine settings and is strongly controlled by glacial input to the North Atlantic. Periodicities of ≈2500, ≈1500, and ≈1000 years are generally observed in the North Atlantic. At the same time spectral analyses of the continental record, which is remote from oceanic influence, reveal persistent periodicities of 1,000 and 500 years that may correspond to solar activity variations during
6650-444: The period exceeds any likely tectonic uplift of non-glacial origin. Post-glacial rebound in the Scandinavia region resulted in a shrinking Baltic Sea . The region continues to rise, still causing weak earthquakes across Northern Europe. An equivalent event in North America was the rebound of Hudson Bay , as it shrank from its larger, immediate post-glacial Tyrrell Sea phase, to its present boundaries. The climate throughout
6745-422: The present. The human impact on modern-era Earth and its ecosystems may be considered of global significance for the future evolution of living species, including approximately synchronous lithospheric evidence, or more recently hydrospheric and atmospheric evidence of the human impact. In July 2018, the International Union of Geological Sciences split the Holocene Epoch into three distinct ages based on
6840-507: The region were dominantly influenced by solar forcing, with many individual cold snaps linked to solar minima such as the Oort, Wolf , Spörer , and Maunder Minima . A notable cooling event in southeastern China occurred 3,200 BP. Strengthening of the winter monsoon occurred around 5,500, 4,000, and 2,500 BP. Monsoonal regions of China became more arid in the Late Holocene. In the Sea of Japan,
6935-612: The region. Sand dune evolution in the Bayanbulak Basin shows that the region was very dry from the Holocene's beginning until around 6,500 BP, when a wet interval began. In the Tibetan Plateau, the moisture optimum spanned from around 7,500 to 5,500 BP. The Tarim Basin records the onset of significant aridification around 3,000-2,000 BP. After 11,800 BP, and especially between 10,800 and 9,200 BP, Ladakh experienced tremendous moisture increase most likely related to
7030-656: The residual glacial ice remaining in the Northern Hemisphere until the later date. The first major phase of Holocene climate was the Preboreal . At the start of the Preboreal occurred the Preboreal Oscillation (PBO). The Holocene Climatic Optimum (HCO) was a period of warming throughout the globe but was not globally synchronous and uniform. Following the HCO, the global climate entered
7125-478: The ridges of the string bogs can grow into hummocks several metres high. Like string bogs, the so-called palsas frequently lie within peatlands fed by mineral soil water. Some are surrounded by water-filled, ditch-like hollows. Peat formation is limited; these bogs are peat deposits from warmer, interglacial periods and did not experience frost heaving of their inner core of ice until the climate became colder. These ice lenses increase in size from year to year as
7220-407: The same time the lower layer becomes peat as the air is excluded. Depending on the geographical location, various species of peat moss are involved in making a raised bog. The growth rate of the peat layer is only about a millimetre per year. Growing bogs can be divided into two layers. The ' acrotelm ' ( Greek : akros = highest; telma = bog) is the upper part and includes the vegetation layer and
7315-400: The sea. For example, marine fossils from the Holocene epoch have been found in locations such as Vermont and Michigan . Other than higher-latitude temporary marine incursions associated with glacial depression, Holocene fossils are found primarily in lakebed, floodplain , and cave deposits. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during
7410-400: The short summers with sufficient moisture, because the meltwater is prevented from draining away by the raised polygonal margins. The peat layers can attain a thickness of 0.3 to 1 m (1.0–3.3 ft). The west Siberian raised bog area covers 700,000 km (270,000 sq mi). The large bogs have domes in the centre up to 10 m (33 ft) high. They are predominantly of
7505-749: The strengthening of the Indian Summer Monsoon (ISM). From 9,200 to 6,900 BP, relative aridity persisted in Ladakh. A second major humid phase occurred in Ladakh from 6,900 to 4,800 BP, after which the region was again arid. From 900 to 1,200 AD, during the MWP, the ISM was again strong as evidenced by low δ O values from the Ganga Plain. The sediments of Lonar Lake in Maharashtra record dry conditions around 11,400 BP that transitioned into
7600-503: The sub-polar zone, north of the 66th latitude in the northern hemisphere. Here, raised bogs only occur as islands within wetlands supplied by mineral soil water. On level ground these islands are irregularly distributed; on hillsides they form ridges parallel to the contours and at right angles to line of slope. The ridges separate boggy hollows of mineral soil known by the Finnish word, rimpis . The main distribution area for string bogs are
7695-465: The surrounding land (due to agriculture and industry ). The last great raised bog regions are found in western Siberia and Canada . The term raised bog derives from the fact that this type of bog rises in height over time as a result of peat formation. They are like sponges of peat moss, full of water, that form a more or less dome shape in the landscape. In Germany, the term Hochmoor ( lit. ' high bog ' ) strictly refers only to
7790-413: The temperature. In addition, the relief of the terrain has an influence on the water discharge behaviour and thus the shape of a raised bog. This results in geographical limitations to the formation of raised bogs. Favourable conditions for the development of raised bogs are found mainly in North America ( Canada and Alaska ), Northern Europe and Western Siberia , South America , Southeast Asia and in
7885-765: The term 'Flandrian' may be used as a synonym for Holocene, although it is becoming outdated. The International Commission on Stratigraphy, however, considers the Holocene to be an epoch following the Pleistocene and specifically following the last glacial period . Local names for the last glacial period include the Wisconsinan in North America , the Weichselian in Europe, the Devensian in Britain,
7980-412: The upper peat layer is called white peat, since it consists of largely undecomposed light brown peat mosses. The lower layer is black peat, which is already well humified and has a black-brown colour with still recognizable plant remains. The formation of raised bogs is dependent on the climate, that is to say the amount of precipitation and rate of evaporation, which in turn are decisively determined by
8075-436: The west by plateau bogs in the area of the large lakes and, eventually, by kermi bogs. Holocene The Holocene ( / ˈ h ɒ l . ə s iː n , - oʊ -, ˈ h oʊ . l ə -, - l oʊ -/ ) is the current geological epoch , beginning approximately 11,700 years ago. It follows the Last Glacial Period , which concluded with the Holocene glacial retreat . The Holocene and the preceding Pleistocene together form
8170-680: The working group's parent bodies (ultimately the International Union of Geological Sciences ). In March 2024, after 15 years of deliberation, the Anthropocene Epoch proposal of the working group was voted down by a wide margin by the SQS, owing largely to its shallow sedimentary record and extremely recent proposed start date. The ICS and the International Union of Geological Sciences later formally confirmed, by
8265-531: The world. Some scholars have argued that a third epoch of the Quaternary, the Anthropocene , has now begun. This term has been used to denote the present time-interval in which many geologically significant conditions and processes have been profoundly altered by human activities. The 'Anthropocene' (a term coined by Paul J. Crutzen and Eugene Stoermer in 2000) was never a formally defined geological unit. The Subcommission on Quaternary Stratigraphy (SQS) of
8360-577: The world. This ' Neolithic Revolution ', likely influenced by Holocene climatic changes, included an increase in sedentism and population, eventually resulting in the world's first large-scale state societies in Mesopotamia and Egypt . During the Middle Holocene, the Intertropical Convergence Zone , which governs the incursion of monsoon precipitation through the Arabian Peninsula, shifted southwards, resulting in increased aridity. In
8455-417: Was around 2.1 metres above present and occurred about 5,800 to 5,000 BP. Sea levels at Rocas Atoll were likewise higher than present for much of the Late Holocene. The Northwest Australian Summer Monsoon was in a strong phase from 8,500 to 6,400 BP, from 5,000 to 4,000 BP (possibly until 3,000 BP), and from 1,300 to 900 BP, with weak phases in between and the current weak phase beginning around 900 BP after
8550-477: Was caused by the melting of glaciers. The most recent age of the Holocene is the present Meghalayan, which began with extreme drought that lasted around 200 years. The word Holocene was formed from two Ancient Greek words. Hólos ( ὅλος ) is the Greek word for "whole". "Cene" comes from the Greek word kainós ( καινός ), meaning "new". The concept is that this epoch is "entirely new". The suffix '-cene'
8645-524: Was coeval with a major humidification before being terminated by a major drought and warming at the end of that interval. During the Early Holocene, relative sea level rose in the Bahia region, causing a landward expansion of mangroves. During the Late Holocene, the mangroves declined as sea level dropped and freshwater supply increased. In the Santa Catarina region, the maximum sea level highstand
8740-603: Was confined to the area immediately south of the STF, and is correlated with reduced westerly winds near New Zealand. Since 7,100 BP, New Zealand experienced 53 cyclones similar in magnitude to Cyclone Bola . Evidence from the Galápagos Islands shows that the El Niño–Southern Oscillation (ENSO) was significantly weaker during the Middle Holocene, but that the strength of ENSO became moderate to high over
8835-467: Was experienced during the MWP. A warming of +1 degree Celsius occurs 5–40 times more frequently in modern years than during the MWP. The major forcing during the MWP was due to greater solar activity, which led to heterogeneity compared to the greenhouse gas forcing of modern years that leads to more homogeneous warming. This was followed by the Little Ice Age (LIA) from the 13th or 14th century to
8930-427: Was formed, although this did not develop simultaneously in all raised bogs. Raised bogs also occur in precipitation-rich upland regions at the montane and, more rarely, alpine levels (i.e. above the tree line ). As a result of the sloping terrain, they often have a characteristic, asymmetric or non-concentric appearance. Mountain or upland bogs may be topographically divided into: All these bog types may occur on
9025-511: Was given the heerlijkheid Westerwolde by the bishop of Münster, and started constructing the Wedderborg , a castle, in Wedde around 1370. In 1619, Westerwolde was purchased by the city of Groningen , and Wedde remained subordinate to the city until 1798. It remained a separate municipality until 1968, when it was merged with Bellingwolde to form Bellingwedde . The new name Bellingwedde
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