The Eemian (also called the last interglacial, Sangamonian Stage, Ipswichian, Mikulin, Kaydaky, penultimate, Valdivia or Riss-Würm) was the interglacial period which began about 130,000 years ago at the end of the Penultimate Glacial Period and ended about 115,000 years ago at the beginning of the Last Glacial Period. It corresponds to Marine Isotope Stage 5e. Although sometimes referred to as the "last interglacial" (in the "most recent previous" sense of "last"), it was the second-to-latest interglacial period of the current Ice Age, the most recent being the Holocene which extends to the present day (having followed the last glacial period). The prevailing Eemian climate was, on average, around 1 to 2 degrees Celsius (1.8 to 3.6 Fahrenheit) warmer than that of the Holocene. However, due to global warming, the past few July global temperatures likely surpassed the (long-term average) July temperatures of the Eemian period. During the Eemian, the proportion of CO
2 in the atmosphere was about 280 parts per million.
The Eemian is known as the Ipswichian in the UK, the Mikulin interglacial in Russia, the Valdivia interglacial in Chile and the Riss-Würm interglacial in the Alps. Depending on how a specific publication defines the Sangamonian Stage of North America, the Eemian is equivalent to either all or part of it.
The Eemian climate is believed to have been about as stable as that of the Holocene. Changes in the Earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as Milankovitch cycles, probably led to greater seasonal temperature variations in the Northern Hemisphere. Although global annual mean temperatures were probably several degrees warmer than today, during summer months, temperatures in the Arctic region were about 2-4 °C higher than today. The warmest peak of the Eemian was around 125,000 years ago, when forests reached as far north as North Cape, Norway (which is now tundra) well above the Arctic Circle at . Hardwood trees such as hazel and oak grew as far north as Oulu, Finland.
At the peak of the Eemian, the Northern Hemisphere winters were generally warmer and wetter than now, though some areas were actually slightly cooler than today. The hippopotamus was distributed as far north as the rivers Rhine and Thames. Trees grew as far north as southern Baffin Island in the Canadian Arctic Archipelago: currently, the northern limit is further south at Kuujjuaq in northern Quebec. Coastal Alaska was warm enough during the summer due to reduced sea ice in the Arctic Ocean to allow Saint Lawrence Island (now tundra) to have boreal forest, although inadequate precipitation caused a reduction in the forest cover in interior Alaska and Yukon Territory despite warmer conditions. The prairie-forest boundary in the Great Plains of the United States lay further west near Lubbock, Texas, whereas the current boundary is near Dallas. The period closed as temperatures steadily fell to conditions cooler and drier than the present, with a 468-year-long aridity pulse in central Europe at about 116,000 BC, and by 112,000 BC, a glacial period had returned.
Kaspar et al. (GRL, 2005) performed a comparison of a coupled general circulation model (GCM) with reconstructed Eemian temperatures for Europe. Central Europe (north of the Alps) was found to be 1–2 °C (1.8–3.6 °F) warmer than present; south of the Alps, conditions were 1–2 °C cooler than today. The model (generated using observed greenhouse gas concentrations and Eemian orbital parameters) generally reproduces these observations, leading them to conclude that these factors are enough to explain the Eemian temperatures.
A 2018 study based on soil samples from Sokli in northern Finland identified abrupt cold spells ca. 120,000 years ago caused by shifts in the North Atlantic Current, lasting hundreds of years and causing temperature drops of a few degrees and vegetation changes in these regions.
Sea level at peak was probably 6 to 9 metres (20 to 30 feet) higher than today, with Greenland contributing 0.6 to 3.5 m (2.0 to 11.5 ft), thermal expansion and mountain glaciers contributing up to 1 m (3.3 ft), and an uncertain contribution from Antarctica. Recent research on marine sediment cores offshore of the West Antarctic Ice Sheet suggest that the sheet melted during the Eemian, and that ocean waters rose as fast as 2.5 meters per century. Global mean sea surface temperatures are thought to have been higher than in the Holocene, but not by enough to explain the rise in sea level through thermal expansion alone, and so melting of polar ice caps must also have occurred. Because of the sea level drop since the Eemian, exposed fossil coral reefs are common in the tropics, especially in the Caribbean and along the Red Sea coastlines. These reefs often contain internal erosion surfaces showing significant sea level instability during the Eemian.
A 2007 study found evidence that the Greenland ice core site Dye 3 was glaciated during the Eemian, which implies that Greenland could have contributed at most 2 m (6.6 ft) to sea level rise. Scandinavia was an island due to the inundation of vast areas of northern Europe and the West Siberian Plain.
The Eemian Stage was first recognized from boreholes in the area of the city of Amersfoort, Netherlands, by Harting (1875). He named the beds "Système Eémien", after the river Eem on which Amersfoort is located. Harting noticed the marine molluscan assemblages to be very different from the modern fauna of the North Sea. Many species from the Eemian layers nowadays show a much more southern distribution, ranging from South of the Strait of Dover to Portugal (Lusitanian faunal province) and even into the Mediterranean (Mediterranean faunal province). More information on the molluscan assemblages is given by Lorié (1887), and Spaink (1958). Since their discovery, Eemian beds in the Netherlands have mainly been recognized by their marine molluscan content combined with their stratigraphical position and other palaeontology. The marine beds there are often underlain by tills that are considered to date from the Saalian, and overlain by local fresh water or wind-blown deposits from the Weichselian. In contrast to e.g. the deposits in Denmark, the Eemian deposits in the type area have never been found overlain by tills, nor in ice-pushed positions.
Van Voorthuysen (1958) described the foraminifera from the type site, whereas Zagwijn (1961) published the palynology, providing a subdivision of this stage into pollen stages. At the end of the 20th century, the type site was re-investigated using old and new data in a multi-disciplinary approach (Cleveringa et al., 2000). At the same time a parastratotype was selected in the Amsterdam glacial basin in the Amsterdam-Terminal borehole and was the subject of a multidisciplinary investigation (Van Leeuwen, et al., 2000). These authors also published a U/Th age for late Eemian deposits from this borehole of 118,200 ± 6,300 years ago. A historical review of Dutch Eemian research is provided by Bosch, Cleveringa and Meijer, 2000.
The Baltic Ice Lake is a name given by geologists to a freshwater lake that gradually formed in the Baltic Sea basin as glaciation retreated from that region at the end of the Pleistocene. The lake, dated to 12,600-10,300 BP, is roughly contemporaneous with the three Pleistocene Blytt-Sernander periods. The lake followed a period of massive glaciation in the region, which followed the end of the Eemian Sea. The post-glacial Yoldia Sea was immediately subsequent to the Baltic Ice Lake.Barrington Pit
Barrington Pit is a 3.8 hectare geological Site of Special Scientific Interest near Barrington in Cambridgeshire. It is a Geological Conservation Review site.This site is described by Natural England as of national importance for its mammal fossils, most of which were found around 1900. Species include hippopotamuses, straight-tusked elephants, lions, aurochs and spotted hyenas. They probably date to the warm Eemian period, around 130,000 to 115,000 years ago.The site is private land, part of which is now covered by housing.Bolshoy Lyakhovsky Island
Bolshoy Lyakhovsky Island (Russian: Большой Ляховский), or Great Lyakhovsky, is the largest of the Lyakhovsky Islands belonging to the New Siberian Islands archipelago between the Laptev Sea and the East Siberian Sea in northern Russia. It has an area of 4,600 km², and a maximum altitude of 270 m (Emy Tas).
The peninsula projecting towards the west of the island is the Kigilyakh Peninsula (Poluostrov Kigilyakh).
Off Bolshoy Lyakhovsky Island's southwestern cape lies a small islet called Ostrov Khopto-Terer.
The Lyakhovsky Islands are named in honour of Ivan Lyakhov, who explored them in 1773.Eemian Sea
The Eemian Sea was a body of water located approximately where the Baltic Sea is now during the last interglacial, or Eemian Stage, Marine isotopic stage (MIS) 5e, roughly 130,000 to 115,000 years BP. Sea level was 5 to 7 metres higher globally than it is today, due to the release of glacial water in the early stage of the interglacial. Although “Eemian” rightly applies only to the northern European glacial system, some scientists use the term in a wider sense to mean any high-level body of water in the last interglacial.
The early Eemian Sea connected with the White Sea along the line of the present White Sea-Baltic Canal. Karelia was inundated and Lakes Ladoga and Onega were mere depressions in the shallow eastern end of the Eemian sea. At the other end the sea connected to the North Sea more broadly than its presently does. Much of northern Europe was under shallow water. Scandinavia was an island. The salinity of the Eemian Sea was comparable to that of the Atlantic. Scientists reach these conclusions from a study of types of micro-organisms fossilized in the clay sediments laid down in the Eemian Sea, and from the included pollen of Corylus, Carpinus and Betula.
During MIS 5e, the mean annual temperature was 3°C higher than today. At its end, during the cooler prelude of MIS 5d, c, b and a, the region continued to rise isostatically. Some water was recaptured in ice. Levels in the Eemian Sea dropped, and the opening to the White Sea was blocked. The post-Eemian brackish lake did not last long geologically speaking, but was covered totally with ice. The Weichselian glaciation starting fully in MIS 4, with an interstadial in 3 and a greatest extent in 2, produced, at its maximum in 20,000-18,000 BP, an ice sheet more than 3 kilometres (1.9 mi) high. As the lake bed was only a few hundred metres deep, no lake could have existed. The ice extended southward into northern Europe as far as France and eastward as far as Poland. At its recession, the Baltic Ice Lake appeared.Eye Gravel Pit
Eye Gravel Pit is a 0.4 hectare geological Site of Special Scientific Interest in Eye Green in Cambridgeshire. It is a Geological Conservation Review site, and part of it overlaps Eye Green Local Nature Reserve.This former gravel quarry in the East Anglian Fens has marine and a few non-marine shells laid down when the area was under the North Sea, probably during the warm Eemian period, 130,000 to 115,000 years ago. It is described by Natural England as important because it lies at the junction between fluvial and glacial deposits.The site is private land with no public access.Geology of the British Indian Ocean Territory
The geology of the British Indian Ocean Territory comprises the Chagos Archipelago—the above water portion of the Chagos Bank. Formed from hotspot volcanism, the Chagos Bank was separated from the Nazareth Bank, which is administered by Mauritius, 36 million years ago by activity on the Central Indian Ridge. Aside from plate boundaries, the region is one of the most seismically active and earthquakes have caused subsidence of some islands.
Described by Charles Darwin as "a ledge of brecciated coral rocks projecting seawards from the outer shore," the Chagos Archipelago has unusual conglomerate platforms. The islands lack Eemian age carbonates, which are present in the Seychelles for reasons that are not clear—hypothesized to include local storm erosion.The offshore waters around the archipelago contain deep-sea ferromanganese nodules, with globular, dendritic and laminated microstructures formed from iron-manganese oxide.
Due to the US military presence on the island the US Geological Survey has conducted water resource analysis since 1984.
The islands of the Chagos Archipelago are mainly low and flat, mainly not reaching two meters above sea level.Greenland ice core project
The Greenland Ice Core Project (GRIP) was a multinational European research project, organized through the European Science Foundation. Funding came from 8 nations (Belgium, Denmark, France, Germany, Iceland, Italy, Switzerland, and United Kingdom), and from the European Union.
The project ran from 1989 to 1995, with drilling seasons from 1990 to 1992. GRIP successfully drilled a 3029-metre ice core to the bed of the Greenland ice sheet at Summit, Central Greenland from 1989 to 1992 at 72°34.74′N 37°33.92′W.
Studies of isotopes and various atmospheric constituents in the core have revealed a detailed record of climatic variations reaching more than 100,000 years back in time. The results indicate that Holocene climate has been remarkably stable and have confirmed the occurrence of rapid climatic variation during the last ice age (the Wisconsin). Delta-O-18 variations observed in the core part believed to date from the Eemian Stage have not been confirmed by other records including the NGRIP core and are now believed not to represent climate events: the interglacial climate of Eemian Stage appears to have been as stable as the Holocene.Histon Road SSSI
Histon Road is a 0.6 hectare geological Site of Special Scientific Interest in Cambridge. It is a Geological Conservation Review site.Histon Road is described by Natural England as a "key Pleistocene stratigraphic site". It is one of only two sites in East Anglia which has an almost complete sequence of the second half of the warm Eemian interglacial, around 120,000 years ago. There are many deposits of molluscs and pollen.The site has been filled in and is now allotments. There is no public access.Interglacial
An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene interglacial began at the end of the Pleistocene, about 11,700 years ago.Knud Jessen
Knud Jessen (29 November 1884 – 14 April 1971) was a Danish botanist and quaternary geologist.
He was state geologist 1917–1931. In 1931, he succeeded C.H. Ostenfeld as professor of botany at the University of Copenhagen and director of the Copenhagen Botanical Garden, a position he held until his retirement in 1955. His scientific works mainly concern vegetation history during the Eemian interglacial, the late glacial period of the Wisconsin glaciation and in the Holocene investigated using pollen analysis.Jessen had come into contact with the Irish naturalist Robert Lloyd Praeger and made field-work on the quaternary geology of Ireland during 1934-1935. Together with his assistant, Frank Mitchell, he was able to describe both the post-glacial vegetation development of Ireland and that of the Eemian interglacial, with the presence in Ireland of such plants as Rhododendron ponticum, Abies alba, Erica scoparia and Buxus sempervirens.Jessen was acknowledged by honorary doctorates at the University of Cambridge and University of Dublin. He was a member of the Royal Danish Academy of Sciences and Letters and served on the board of directors of the Carlsberg Foundation.Late Pleistocene
The Late Pleistocene is a geochronological age of the Pleistocene Epoch and is associated with Upper Pleistocene (or Tarantian) stage rocks. The beginning of the stage is defined by the base of the Eemian interglacial phase before the final glacial episode of the Pleistocene 126,000 ± 5,000 years ago. Its end is defined at the end of the Younger Dryas, some 11,700 years ago. The age represents the end of the Pleistocene epoch and is followed by the Holocene epoch.
Much of the Late Pleistocene age was dominated by glaciations, such as the Wisconsin glaciation in North America and the Weichselian glaciation and Würm glaciation in Eurasia. Many megafauna became extinct during this age, a trend that continued into the Holocene. The Late Pleistocene contains the Upper Paleolithic stage of human development, including the out-of-Africa migration and dispersal of anatomically modern humans and the extinction of the last remaining archaic human species.Micoquien
The Micoquien is an early middle paleolithic industry, that is found in the Eemian and in an early episode of the Würm glaciation (about 130,000 to 60,000 BCE). The Micoquien is distinguished technologically by the appearance of distinctly asymmetrical bifaces. Its discoverer and namer was the archeologist and art trader Otto Hauser. Hauser then sold a great number of so-called Micoque-wedges that he found in excavations in La Micoque (in Les Eyzies-de-Tayac-Sireuil, Dordogne, France) to museums and collectors.
The specially formed handaxes from La Micoque exhibited an often a rounded base. The problem with the term Micoquien is that later excavations have revealed an older time placement for the La Micoque axes, which are now dated in the Riss glaciation.
A wider artifact from the Micoquien is the Keilmesser (bifacially worked knife), which has a clearer chronology in Central Europe. From this some archeologists have proposed substituting the term Keilmesser group for Micoquien.Micoquien artifacts are distributed across all of Eastern Europe and Central Europe. In Germany they can be found at Balver Höhle and Lonetal.NEEM Camp
NEEM Camp was a small research facility on the northern Greenland Ice Sheet, used as a base for ice core drilling. It is located about 313 km east of the closest coast, Peabody Bay in northern Greenland, 275 km northwest of the historical ice sheet camp North Ice, and 484 km ENE of Siorapaluk, the closest settlement. There is only one heavy-duty tent for accommodation of the researchers during summer. Access is by skiway (snow runway).
The acronym NEEM stands for North Greenland Eemian Ice Drilling. The ice at the NEEM coring location (77°27'N 51°3.6'W) was predicted to be 2545 m thick.
Drilling started at NEEM in June 2009 and drillers expected to hit bedrock in 2010. The drilling progressed well and reached through the brittle zone (~800 m) in mid-July 2009. The plan was to process the ice below the brittle zone, per decision at the steering committee meeting in November 2008 in Copenhagen.By September 1, 2009, the coring had reached 1757.84 m for this season, setting a single-season deep ice core drilling record in 100 days.On July 26, 2010, drilling reached bedrock at 2537.36 m.The November/December 2007 issue of Technology Review magazine and its website carried a report on early efforts to establish this camp. The research goal is to seek preserved ice from the Eemian, which included a warming period in Earth's history. http://www.technologyreview.com/Energy/19504/
After the conclusion of the drilling activities, the machinery and dome of the NEEM camp was moved to a new location in the NEEM-EastGRIP traverse, forming the EastGRIP camp at location 75.63°N 35.99°W / 75.63; -35.99 in 2015.North Greenland Ice Core Project
The drilling site of the North Greenland Ice Core Project (NGRIP or NorthGRIP) is near the center of Greenland (75.1 N, 42.32 W, 2917 m, ice thickness 3085). Drilling began in 1999 and was completed at bedrock in 2003. The cores are cylinders of ice 11 centimeters in diameter that were brought to the surface in 3.5-meter lengths. The NGRIP site was chosen to extract a long and undisturbed record stretching into the last glacial, and it succeeded. The site was chosen for a flat basal topography to avoid the flow distortions that render the bottom of the GRIP and GISP cores unreliable. Unusually, there is melting at the bottom of the NGRIP core - believed to be due to a high geothermal heat flux locally. This has the advantage that the bottom layers are less compressed by thinning than they would otherwise be: NGRIP annual layers at 105 kyr age are 1.1 cm thick, twice the GRIP thicknesses at equal age.
The NGRIP record helps to resolve a problem with the GRIP and GISP2 records - the unreliability of the Eemian Stage portion of the record. NGRIP covers 5 kyr of the Eemian, and shows that temperatures then were roughly as stable as the pre-industrial Holocene temperatures were. This is confirmed by sediment cores, in particular MD95-2042.In 2003, NGRIP recovered what seem to be plant remnants nearly two miles below the surface, and they may be several million years old."Several of the pieces look very much like blades of grass or pine needles," said University of Colorado at Boulder geological sciences Professor James White, an NGRIP principal investigator. "If confirmed, this will be the first organic material ever recovered from a deep ice-core drilling project," he said.Penultimate Glacial Period
The Penultimate Glacial Period (PGP) is the glacial period that occurred before the Last Glacial Period. It began ~194,000 years ago, and ended 135,000 years ago with the beginning of the Eemian interglacial. It roughly coincides with Marine Isotope Stage 6 (see Marine Isotope Stage) and the Illinoian Stage. The penultimate glacial period is one of a series of glacial and interglacial periods of the Quaternary Ice Age/Quaternary Glaciation. The Quaternary Ice Age began 2.58 million years ago and is ongoing. It began with the formation of the Arctic Ice Cap. The Quaternary Ice Age is part of an even longer ice age called the Late Cenozoic Ice Age. It began 33.9 million years ago and is also ongoing. It began with the formation of the Antarctic Ice Cap.Just like the Last Glacial Period, the penultimate glacial period has no name. The word penultimate means second to last.
The penultimate glacial period was at least the second glacial period that Neanderthals, Denisovans, and Homo sapiens experienced.
Penultimate Glacial Period was more severe than the Last Glacial Period.Sangamonian
The Sangamonian Stage (or Sangamon interglacial) is the term used in North America to designate the last interglacial period. In its most common usage, it is used for the period of time between 75,000 and 125,000 BP. This period of time is equivalent to all of Marine Isotope Stage 5 and the combined Eemian period and early part of the Weichselian glaciation in Europe. Less commonly, the Sangamonian Stage is restricted to the period between 122,000 and 132,000 BP, which is equivalent to Marine Oxygen Isotope Substage 5e and the Eemian period of Europe. It preceded the Wisconsinan (Wisconsin) Stage and followed the Illinoian Stage in North America.Selsey, East Beach
Selsey, East Beach is a 1.7-hectare (4.2-acre) geological Site of Special Scientific Interest in Selsey in West Sussex. It is a Geological Conservation Review site.This site exposes a sequence of marine estuary and freshwater deposits dating to the warm Eemian interglacial. The site has fossils of fauna dating to the early Eemian around 130 thousand years ago, such as straight-tusked elephant, an extinct species of rhinoceros, Dicerorhinus hemitoechus, European pond tortoise, beaver and horse.This short stretch of shingle beach is open to the public but no geology is visible.Weichselian glaciation
Weichselian glaciation was the last glacial period and its associated glaciation in Northern Europe. In the Alpine region it corresponds to the Würm glaciation. It was characterized by a large ice sheet (the Fenno-Scandian ice sheet) that spread out from the Scandinavian Mountains and extended as far as the east coast of Schleswig-Holstein, the March of Brandenburg and Northwest Russia.
In Northern Europe it was the youngest of the glacials of the Pleistocene ice age. The preceding warm period in this region was the Eemian interglacial. The last cold period began about 115,000 years ago and ended 11,700 years ago. Its end corresponds with the end of the Pleistocene epoch and start of the Holocene. The name Weichselian glaciation was given by German geologist Konrad Keilhack.Wolstonian Stage
The Wolstonian Stage is a middle Pleistocene stage of the geological history of Earth that precedes the Ipswichian Stage (Eemian Stage in Europe) and follows the Hoxnian Stage in the British Isles. The Wolstonian Stage apparently includes three periods of glaciation. The Wolstonian Stage is temporally analogous to the Warthe Stage and Saalian Stage in northern Europe and the Riss glaciation in the Alps, and temporally equivalent to all of the Illinoian Stage and the youngest part of the Pre-Illinoian Stage in North America. It is contemporaneous with the North American Pre-Illinoian A, Early Illinoian, and Late Illinoian glaciations. The Wolstonian Stage is equivalent to Marine Isotope stages 6 through 10. It started 352,000 years ago and ended 130,000 years ago.The Wolstonian Stage was named after the site of Wolston in the English county of Warwickshire where corresponding deposits were first identified. Acheulian flint tools have been found in Wolstonian deposits.
The cold and warm periods of the Quaternary in North Germany
The cold and warm periods of the Quaternary in the Alpine region