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111-689: The Larsen Ice Shelf is a long ice shelf in the northwest part of the Weddell Sea , extending along the east coast of the Antarctic Peninsula from Cape Longing to Smith Peninsula . It is named after Captain Carl Anton Larsen , the master of the Norwegian whaling vessel Jason , who sailed along the ice front as far as 68°10' South during December 1893. In finer detail, the Larsen Ice Shelf

222-415: A "hotspot of global warming". It broke over a period of three weeks or less, with a factor in this fast break-up being the powerful effects of water; ponds of meltwater formed on the surface during the near 24 hours of daylight in the summertime, flowed down into cracks and, acting like a multitude of wedges, levered the shelf apart. Other likely factors in the break-up were the higher ocean temperatures and

333-700: 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

444-403: A factor in this fast break-up being the powerful effects of water; ponds of meltwater formed on the surface during the near 24 hours of daylight in the summertime, flowed down into cracks and, acting like a multitude of wedges, levered the shelf apart. Other likely factors in the break-up were the higher ocean temperatures and the decline of the ice of the peninsula. In the austral winter of 2011,

555-515: A huge ice island in 2017. From 31 January 2002 to March 2002 the Larsen B sector partially collapsed and parts broke up, 3,250 km (1,250 sq mi) of ice 220 m (720 ft) thick, an area comparable to the US state of Rhode Island . In 2015, a study concluded that the remaining Larsen B ice-shelf would disintegrate by 2020, based on observations of faster flow and rapid thinning of glaciers in

666-594: A large crack in the Ward Hunt shelf had begun to form, and in 2003 it was announced that the ice sheet had split completely in two in 2002, releasing a huge pool of freshwater from the largest epishelf lake in the Northern Hemisphere, located in Disraeli Fjord. In April 2008, scientists discovered that the shelf fractured into dozens of deep, multi-faceted cracks. On August 13, 2005, The Ayles Ice Shelf , which

777-558: A large expanse of sea ice formed over the embayment that was once covered by the land-fast shelf of fresh-water glacial ice of Larsen B. This enormous ice pack persisted through January 2022 when it suddenly broke-up over the course of a few days, "taking with it a Philadelphia-sized piece of the Scar Inlet Ice Shelf ," according to NASA scientists examining images from the Terra and Aqua satellites. As of July 2017, Larsen C

888-593: 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

999-552: 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

1110-414: A mile) below the sea. The discovery was accidental. U.S. Antarctic Program scientists were in the north-western Weddell Sea investigating the sediment record in a deep glacial trough of roughly 1,000,000 square kilometres (390,000 sq mi) (twice the size of Texas or France ). Methane and hydrogen sulfide associated with cold seeps is suspected as the source of the chemical energy powering

1221-643: 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

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1332-567: 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

1443-596: 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

1554-467: 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

1665-399: A shelf front will extend forward for years or decades between major calving events (calving is the sudden release and breaking away of a mass of ice from a glacier , iceberg , ice front , ice shelf, or crevasse ). Snow accumulation on the upper surface and melting from the lower surface are also important to the mass balance of an ice shelf. Ice may also accrete onto the underside of

1776-536: A slow melt rate, in contrast to the undefended western portion. According to the American Geophysical Union in a 2021 study, the Thwaites Eastern Ice Shelf (TEIS) buttresses one-third of Thwaites glacier . Removal of the shelf has the potential to increase the contribution of Thwaites glacier to sea level rise by up to 25%. As of 2021 , the ice shelf appears to be losing its grip on

1887-454: A submarine shoal that acts as a pinning point and the shear margin that separates the Thwaites Eastern Ice Shelf from the Thwaites glacier Tongue has extended, further weakening the ice shelf connection to the pinning point. A sequence of Sentinel-1 radar imagery shows that parallel wing and comb cracks have recently formed rifts at high angles to the main shear margin and are propagating into

1998-440: A trillion tons and is more than 200 m (700 ft) thick. Project MIDAS updated their blog information on 19 July 2017 regarding Larsen C by revealing that a possible new rift appeared to be extending northwards from the point where A-68 had broken off in mid-July. The project researchers felt this questionable new rift might turn towards the shelf edge, compounding the risk that it would "continue on to Bawden ice rise" which

2109-501: 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 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

2220-475: Is a series of shelves that occupy (or occupied) distinct embayments along the coast. From north to south, the segments are called Larsen A (the smallest), Larsen B, and Larsen C (the largest) by researchers who work in the area. Further south, Larsen D and the much smaller Larsen E, F and G are also named. The breakup of the ice shelf since the mid-1990s has been widely reported, with the collapse of Larsen B in 2002 being particularly dramatic. A large section of

2331-516: Is about 1028 kg/m and that of glacial ice from about 850 kg/m to well below 920 kg/m , the limit for very cold ice without bubbles. The height of the shelf above the sea can be even larger, if there is much less dense firn and snow above the glacier ice. A large portion of the Antarctic coastline has ice shelves attached. Their aggregate area is over 1,550,000 square kilometers (600,000 square miles). It has been found that of all

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2442-500: Is all that prevents the birth of an enormous iceberg. "The rift tip appears also to have turned significantly towards the ice front, indicating that the time of calving is probably very close," Adrian Luckman and Martin O'Leary wrote on Wednesday in a blog post for the Impact of Melt on Ice Shelf Dynamics and Stability project, or MIDAS. "There appears to be very little to prevent the iceberg from breaking away completely." The larger swath of

2553-422: Is considered "a crucial point of stabilization for Larsen C Ice Shelf." As is true of all floating ice shelves, A68's departure from Antarctica had no immediate effect on global sea levels . However, a number of glaciers discharge onto the shelf from the land behind it, and they may now flow faster due to reduced support from the ice shelf. If all the ice that the Larsen C shelf currently holds back were to enter

2664-510: Is fast ice along the entire front. This makes it difficult to interpret the ice front because the semi-permanent sea ice varies in thickness and may be nearly indistinguishable from shelf ice. 67°30′S 62°30′W  /  67.500°S 62.500°W  / -67.500; -62.500 Ice shelf Ice shelves are found in Antarctica and the Arctic ( Greenland , Northern Canada , and

2775-548: Is formed on water, is much thinner (typically less than 3 m (9.8 ft)), and forms throughout the Arctic Ocean . It is also found in the Southern Ocean around the continent of Antarctica . The term captured ice shelf has been used for the ice over a subglacial lake , such as Lake Vostok . Ice shelves are thick plates of ice, formed continuously by glaciers, that float atop an ocean. The shelves act as "brakes" for

2886-604: Is one of the biggest ice shelves in West Antarctica , though it is highly unstable and disintegrating rapidly. Since the 1980s, the Thwaites Glacier , nicknamed the "Doomsday glacier", has had a net loss of over 600 billion tons of ice, though pinning of the Thwaites Ice Shelf has served to slow the process. The Thwaites Ice Shelf has acted like a dam for the eastern portion of glacier, bracing it and allowing for

2997-644: 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 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

3108-547: 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

3219-603: 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,

3330-717: 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

3441-584: The Karpinsky Ice Cap to the south and the Rusanov Ice Cap to the north. In 2012 it ceased to exist. In the last several decades, glaciologists have observed consistent decreases in ice shelf extent through melt, calving , and complete disintegration of some shelves. Well studied examples include disruptions of the Thwaites Ice Shelf , Larsen Ice Shelf , Filchner–Ronne Ice Shelf (all three in

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3552-634: The Markham Ice Shelf broke up in 2008. The remaining ice shelves have also lost a significant amount of their area over time, with the Milne Ice Shelf being the last to be affected, with it breaking off in August 2020. The Matusevich Ice Shelf was a 222 square kilometers (86 square miles) ice shelf located in Severnaya Zemlya being fed by some of the largest ice caps on October Revolution Island ,

3663-664: 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 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)

3774-628: 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

3885-644: The Russian Arctic ), and can range in thickness from about 100–1,000 m (330–3,280 ft). The world's largest ice shelves are the Ross Ice Shelf and the Filchner-Ronne Ice Shelf in Antarctica. The movement of ice shelves is principally driven by gravity -induced pressure from the grounded ice. That flow continually moves ice from the grounding line to the seaward front of the shelf. Typically,

3996-565: 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

4107-965: 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, 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

4218-535: 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,

4329-604: The Antarctic) and the disruption of the Ellesmere Ice Shelf in the Arctic. An ice shelf is "a floating slab of ice originating from land of considerable thickness extending from the coast (usually of great horizontal extent with a very gently sloping surface), resulting from the flow of ice sheets , initially formed by the accumulation of snow, and often filling embayments in the coastline of an ice sheet." In contrast, sea ice

4440-488: The Antarctic) and the disruption of the Ellesmere Ice Shelf in the Arctic. The effects of climate change are visible in the changes to the cryosphere , such as reduction in sea ice and ice sheets , and disruption of ice shelves. Thwaites Ice Shelf (), is an Antarctic ice shelf in the Amundsen Sea . It was named by ACAN after Fredrik T. Thwaites, a glacial geologist and geomorphologist . The Thwaites Ice Shelf

4551-648: 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

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4662-537: The Ellesmere Ice Shelf had been in place for at least 3,000 years. During the twentieth century, the Ellesmere Ice Shelf broke up into six separate shelves. From west to east, these were the Serson Ice Shelf , Petersen Ice Shelf , Milne Ice Shelf , Ayles Ice Shelf , Ward Hunt Ice Shelf , and Markham Ice Shelf . The smaller pieces continued to disintegrate. In April 2000, satellite images revealed that

4773-576: 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

4884-474: 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

4995-480: 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

5106-658: The International Union of Geological Sciences later formally confirmed, by 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

5217-425: The Larsen B sector partially collapsed and parts broke up, 3,250 km (1,250 sq mi) of ice 220 m (720 ft) thick, an area comparable to the US state of Rhode Island . In 2015, a study concluded that the remaining Larsen B ice-shelf would disintegrate by 2020, based on observations of faster flow and rapid thinning of glaciers in the area. Larsen B was stable for at least 10,000 years, essentially

5328-480: The Larsen C ice shelf that sat behind the calved iceberg "will be less stable than it was prior to the rift" and may rapidly disintegrate in the same manner as Larsen B did in 2002. In June 2017 the speed of the imminent Larsen C iceberg accelerated, with the eastern end moving at 10 metres (33 ft) per day away from the main shelf. As discussed by the Project MIDAS researchers on their site: "In another sign that

5439-475: The Larsen C shelf broke away in July 2017 to form an iceberg known as A-68 . The ice shelf originally covered an area of 85,000 square kilometres (33,000 sq mi), but following the disintegration in the north and the break away of iceberg A-17 , it now covers an area of 67,000 square kilometres (26,000 sq mi). The collapse of Larsen B has revealed a thriving chemotrophic ecosystem 800 m (half

5550-437: 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

5661-476: 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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5772-454: 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

5883-625: 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

5994-507: The Milne Ice Shelf, also ultimately experienced a major breakup at the end of July 2020, losing over 40% of its area. The Ellesmere Ice Shelf was the largest ice shelf in the Arctic, encompassing about 9,100 square kilometres (3,500 square miles) of the north coast of Ellesmere Island , Nunavut , Canada. The ice shelf was first documented by the British Arctic Expedition of 1875–76, in which Lieutenant Pelham Aldrich 's party went from Cape Sheridan to Cape Alert . The continuous mass of

6105-407: The November 2006 sighting of several large icebergs from the coast of the South Island of New Zealand , the first time since 1931 that any icebergs had been observed from the New Zealand mainland. A large group of small icebergs (the largest some 1000 metres in length), were seen off the south-east coast of the island, with one of them drifting close enough to shore to be visible from the hills above

6216-400: The area. Larsen B was stable for at least 10,000 years, essentially the entire Holocene period since the last glacial period. By contrast, Larsen A was absent for a significant part of that period, reforming about 4,000 years ago. Despite its great age, the Larsen B was clearly in trouble at the time of the collapse. With warm currents eating away the underside of the shelf, it had become

6327-471: 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

6438-453: The central part of the ice shelf at rates as high as 2 km per year. Satellite data, ground-penetrating radar, and GPS measurements taken in 2021 indicate that collapse of the ice shelf may be initiated by intersection of rifts with hidden basal crevasse zones as soon as 2026. Two sections of Antarctica's Larsen Ice Shelf broke apart into hundreds of unusually small fragments (hundreds of meters wide or less) in 1995 and 2002, Larsen C calved

6549-647: The city of Dunedin . If these were indeed the remnants of this calving, then over the course of five and a half years they had travelled slowly north and also east around over half the globe, a journey of some 13,500 km. From January 12 and January 13, 2010, an area of sea ice larger than the state of Rhode Island , or one-seventh the size of Wales , broke away from the Ronne–Filchner Ice Shelf and shattered into many smaller pieces. The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua and Terra satellites captured this event in this series of photo-like images. In May 2021, Iceberg A-76 broke off

6660-409: The decline of the ice of the peninsula. In October 1998, the iceberg A-38 broke off the Filchner–Ronne ice shelf. It had an extent of roughly 150 by 50 km and was thus larger than Delaware . It later broke up again into three parts. A similar-sized calving in May 2000 created an iceberg 167 by 32 km in extent, dubbed A-43 – the disintegration of this is thought to have been responsible for

6771-402: 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

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6882-473: 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

6993-541: The ecosystem. The area had been protected by the overlying ice shelf from debris and sediment which was seen to be building up on the white microbial mats after the breakup of the ice shelf. Clams were observed clustered about the vents. The former Larsen A region, which was the farthest north and was just outside the Antarctic Circle , had previously broken up in the middle of the present interglacial and reformed only about 4,000 years ago. The former Larsen B, by contrast, had been stable for at least 10,000 years. The ice of

7104-427: 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

7215-484: 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

7326-410: The entire Holocene period since the last glacial period. By contrast, Larsen A was absent for a significant part of that period, reforming about 4,000 years ago. Despite its great age, the Larsen B was clearly in trouble at the time of the collapse. With warm currents eating away the underside of the shelf, it had become a "hotspot of global warming". It broke over a period of three weeks or less, with

7437-424: 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

7548-509: The floating ice is above the ocean surface, depending on how much pressurized air is contained in the bubbles within the glacial ice, stemming from compressed snow. The formula for the denominators above is 1 / [ ( ρ seawater − ρ glacial ice ) / ρ seawater ] {\textstyle 1/[(\rho _{\text{seawater}}-\rho _{\text{glacial ice}})/\rho _{\text{seawater}}]} , density of cold seawater

7659-410: The following decade. The breakaway process for the iceberg had begun by mid-2016. On 10 November 2016 scientists photographed the growing rift running along the Larsen C ice shelf, showing it running about 110 kilometres (68 mi) long with a width of more than 91 m (299 ft), and a depth of 500 m (1,600 ft). By December 2016, the rift had extended another 21 km (13 mi) to

7770-461: 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 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

7881-595: The glaciers. These shelves serve another important purpose—"they moderate the amount of melting that occurs on the glaciers' surfaces. Once their ice shelves are removed, the glaciers increase in speed due to meltwater percolation and/or a reduction of braking forces, and they may begin to dump more ice into the ocean than they gather as snow in their catchments. Glacier ice speed increases are already observed in Peninsula areas where ice shelves disintegrated in prior years." The density contrast between glacial ice and liquid water means that at least ⁠ 1 / 9 ⁠ of

7992-473: The ice shelf. The Ellesmere ice shelf was reduced by 90% in the twentieth century, leaving the separate Alfred Ernest , Ayles , Milne , Ward Hunt , and Markham ice shelves. A 1986 survey of Canadian ice shelves found that 48 km (3.3 cubic kilometres) of ice calved from the Milne and Ayles ice shelves between 1959 and 1974. The Ayles Ice Shelf calved entirely on August 13, 2005. The Ward Hunt Ice Shelf,

8103-422: The ice shelves on Earth, nearly all of them are in Antarctica. In steady state, about half of Antarctica's ice shelf mass is lost to basal melt and half is lost to calving , but the relative importance of each process varies significantly between ice shelves. In recent decades, Antarctica's ice shelves have been out of balance, as they have lost more mass to basal melt and calving than has been replenished by

8214-423: The iceberg calving is imminent, the soon-to-be-iceberg part of Larsen C ice shelf has tripled in speed to more than 10 meters per day between 24 and 27 June 2017. The iceberg remains attached to the ice shelf, but its outer end is moving at the highest speed ever recorded on this ice shelf." On 7 July the Project MIDAS blog report stated: "The latest data from 6th July reveal that, in a release of built-up stresses,

8325-448: The influx of new ice and snow. The Ross Ice Shelf is the largest ice shelf of Antarctica (as of 2013 , an area of roughly 500,809 square kilometres (193,363 sq mi) and about 800 kilometres (500 mi) across: about the size of France). It is several hundred metres thick. The nearly vertical ice front to the open sea is more than 600 kilometres (370 mi) long, and between 15 and 50 metres (50 and 160 ft) high above

8436-550: The largest remaining section of thick (>10 meters (33 feet)) landfast sea ice along the northern coastline of Ellesmere Island, lost 600 square kilometers (230 square miles) of ice in a massive calving in 1961–1962. It further decreased by 27% in thickness (13 meters (43 feet)) between 1967 and 1999. In the summer of 2002, the Ward Ice Shelf experienced another major breakup, and other instances of note happened in 2008 and 2010 as well. The last remnant to remain mostly intact,

8547-489: 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 the present. The human impact on modern-era Earth and its ecosystems may be considered of global significance for

8658-547: The late 1940s. According to a paper published in Journal of Climate in 2006, the peninsula at Faraday station warmed by 2.94˚C (5.3˚F) from 1951 to 2004, much faster than Antarctica as a whole and faster than the global trend; anthropogenic global warming causes this localized warming through a strengthening of the winds circling the Antarctic. The Larsen A ice shelf disintegrated in January 1995. From 31 January 2002 to March 2002

8769-522: 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

8880-698: 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

8991-618: 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

9102-481: The northwest corner of the shelf. At 4320 km , it is larger than Majorca , several times larger than Iceberg A-74 which calved in the same year, or approximately 14% the size of Belgium . The ice of the Filchner–Ronne ice shelf can be as thick as 600 m; the water below is about 1400 m deep at the deepest point. The international Filchner–Ronne Ice Shelf Programme (FRISP) was initiated in 1973 to study

9213-571: 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

9324-539: 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

9435-422: The overall ice-sheet mass balance in Antarctica is increasingly negative. The Larsen disintegration events were unusual by past standards. Typically, ice shelves lose mass by iceberg calving and by melting at their upper and lower surfaces. The disintegration events were linked by The Independent newspaper in 2005 to ongoing climate warming in the Antarctic Peninsula , about 0.5˚C (0.9˚F) per decade since

9546-553: 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

9657-503: The point where only 20 km (12 mi) of unbroken ice remained and calving was considered to be a certainty in 2017. This was predicted to cause the calving of between nine and twelve percent of the ice shelf, 6,000 km (2,300 sq mi), an area greater than the US state of Delaware , or twice the size of Luxembourg . The calved fragment was predicted to be 350 m (1,150 ft) thick and to have an area of about 5,000 km (1,900 sq mi). The resulting iceberg

9768-508: 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 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

9879-500: 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,

9990-597: 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

10101-628: 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

10212-500: The rift branched several times. Using data from ESA's Sentinel-1 satellites, we can see that there are multiple rift tips now within 5 km (3.10 miles) of the ice edge. We expect that these rifts will lead to the formation of several smaller icebergs." On 12 July 2017, Project MIDAS announced that a large, 5,800-square-kilometre (2,200 sq mi) portion of Larsen C had broken from the main ice shelf at some point between 10 and 12 July. The iceberg, designated A-68 , weighs more than

10323-453: The sea, global waters would rise by an estimated 10 cm (4 in). The Larsen D Ice Shelf is between Smith Peninsula in the south and Gipps Ice Rise . It is considered to be generally stable. Over roughly the past fifty years it has advanced (expanded) whereas comparable George VI , Bach , Stange , and Larsen C ice shelves have retreated (to a much greater net extent). The most recent survey of Larsen D measured it at 22,600 km. There

10434-400: 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

10545-403: The shelf is renewed on a much shorter time-scale and the oldest ice on the current shelf dates from only two hundred years ago. The speed of Crane Glacier increased threefold after the collapse of the Larsen B, likely due to the removal of a buttressing effect of the ice shelf. Data collected in 2007 by an international team of investigators through satellite-based radar measurements suggests that

10656-474: The shelf. The effects of climate change are visible in the changes to the cryosphere , such as reduction in sea ice and ice sheets , and disruption of ice shelves. In the last several decades, glaciologists have observed consistent decreases in ice shelf extent through melt, calving , and complete disintegration of some shelves. Well studied examples include disruptions of the Thwaites Ice Shelf , Larsen Ice Shelf , Filchner–Ronne Ice Shelf (all three in

10767-721: 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

10878-453: 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 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

10989-537: The water surface. Ninety percent of the floating ice, however, is below the water surface. All Canadian ice shelves are attached to Ellesmere Island and lie north of 82°N. Ice shelves that are still in existence are the Alfred Ernest Ice Shelf , Ward Hunt Ice Shelf , Milne Ice Shelf and Smith Ice Shelf . The M'Clintock Ice Shelf broke up from 1963 to 1966; the Ayles Ice Shelf broke up in 2005; and

11100-563: 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

11211-417: 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

11322-513: 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

11433-592: 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

11544-414: 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 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

11655-460: 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

11766-626: 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' 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

11877-526: Was located approximately 800 km (500 mi) south of the North Pole , broke away from the coast forming the giant Ayles Ice Island 37 metres (121 ft) thick and measuring around 14 by 5 km (8.7 by 3.1 mi) in size with an area of approximately 66 km (25 sq mi) or 2.6 km (0.62 cu mi) in volume. Holocene The Holocene ( / ˈ h ɒ l . ə s iː n , - oʊ -, ˈ h oʊ . l ə -, - l oʊ -/ )

11988-550: Was never a formally defined geological unit. The Subcommission on Quaternary Stratigraphy (SQS) of 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

12099-560: Was predicted to be among the largest icebergs ever recorded , unless it would break into multiple pieces. On 1 May 2017 members of MIDAS reported that satellite images showed a new crack, around 15 km (9 mi) long, branching off the main crack approximately 10 km (6 mi) behind the previous tip, heading toward the ice front. Scientists with Swansea University in the UK say the crack lengthened 18 km (11 mi) from 25 May to 31 May, and that less than 13 km (8 mi) of ice

12210-599: Was still to be determined, after which the recommendation also had to be approved by 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

12321-408: Was the fourth largest ice shelf in Antarctica, with an area of about 44,200 km (17,100 sq mi). Satellite radar altimeter measurements show that between 1992 and 2001, the Larsen Ice Shelf thinned by up to 0.27 ± 0.11 meters per year. In 2004, a report concluded that although the remaining Larsen C region appeared to be relatively stable, continued warming could lead to its breakup within

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