{{Short description|Ancient warm and cool periods}} [[File:Five Myr Climate Change.svg|400px|thumb|5-million-year history, representing the Lisiecki and Raymo (2005) LR04 Benthic Stack]] [[File:PS1920-1 0-750 sediment-core hg.jpg|thumb|Sections of sedimentary cores from off [[Greenland]]]]
'''Marine isotope stages''' ('''MIS'''), '''marine oxygen-isotope stages''', or '''oxygen isotope stages''' ('''OIS'''), are alternating warm and cool periods in the Earth's [[paleoclimate]], deduced from [[Oxygen isotope ratio cycle|oxygen isotope data]] derived from deep sea [[core sample]]s. Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of [[oxygen-18]] and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm [[interglacial]] intervals. The data are derived from [[pollen]] and [[foraminifera]] ([[plankton]]) remains in drilled [[marine sediment]] cores, [[sapropel]]s, and other data that reflect historic climate; these are called [[Proxy (climate)|proxies]].
The MIS timescale was developed from the pioneering work of [[Cesare Emiliani]] in the 1950s, modifying an earlier system introduced by oceanographer [[Svante Arrhenius#Marriages and family|Gustaf Arrhenius]]. It is now widely used in [[archaeology]] and other fields to express dating in the [[Quaternary]] period (the last 2.6 million years), as well as providing the fullest and best data for that period for [[paleoclimatology]] or the study of the early climate of the Earth,<ref>Wright, 427, 429; Aitken & Stokes (1997), 9-14</ref> representing "the standard to which we correlate other Quaternary climate records".<ref>Sowers, 425</ref> Emiliani's work in turn depended on [[Harold Urey]]'s prediction in a paper of 1947 that the ratio between oxygen-18 and [[oxygen-16]] isotopes in [[calcite]], the main chemical component of the shells and other hard parts of a wide range of marine organisms, should vary depending on the prevailing water temperature in which the calcite was formed.<ref>Wright, 427</ref>
Over 100 stages have been identified, currently going back some 6 million years, and the scale may eventually reach back as far as 15 million years. Some stages, in particular MIS 5, are divided into sub-stages, such as "MIS 5a", with 5 a, c, and e being warm and b and d cold. A numeric system for referring to "horizons" (events rather than periods) may also be used, with for example MIS 5.5 representing the peak point of MIS 5e, and 5.51, 5.52 etc. representing the peaks and troughs of the record at a still more detailed level. For more recent periods, increasingly precise resolution of timing continues to be developed.<ref>Aitken & Stokes (1997), 12; Wright, 429–431</ref>
==Developing a timescale== {{See also|Timeline of glaciation}} [[File:2000 core-repository02 hg.jpg|thumb|left|A store of core samples]] In 1957 Emiliani moved to the [[University of Miami]] to have access to core-drilling ships and equipment, and began to drill in the [[Caribbean]] and collect core data. A further important advance came in 1967, when [[Nicholas Shackleton]] suggested that the fluctuations over time in the marine isotope ratios that had become evident by then were caused not so much by changes in water temperature, as Emiliani thought, but mainly by changes in the volume of ice-sheets, which when they expanded took up the lighter oxygen-16 isotope in preference to the heavier oxygen-18.<ref>Cronin, 120–121</ref> The cycles in the isotope ratio were found to correspond to [[Ecoregion#Terrestrial|terrestrial]] evidence of glacials and interglacials. A graph of the entire series of stages then revealed unsuspected advances and retreats of ice and also filled in the details of the [[stadial|stadials and interstadials]].
More recent [[ice core]] samples of today's glacial ice substantiated the cycles through studies of ancient [[pollen]] deposition. Currently a number of methods are making additional detail possible. Matching the stages to named periods proceeds as new dates are discovered and new regions are explored geologically. The marine isotopic records appear more complete and detailed than any terrestrial equivalents, and have enabled a timeline of glaciation for the [[Plio-Pleistocene]] to be identified.<ref>Wright, 431</ref> It is now believed that changes in the size of the major [[ice sheet]]s such as the historical [[Laurentide Ice Sheet]] of North America are the main factor governing variations in the oxygen isotope ratios.<ref>Andrews, 448</ref>
The MIS data also matches the astronomical data of [[Milankovitch cycles]] of [[orbital forcing]] or the effects of variations in [[insolation]] caused by cyclical slight changes in the tilt of the Earth's axis of rotation – the "orbital theory". Indeed, that the MIS data matched Milankovich's theory, which he formed during World War I, so well was a key factor in the theory gaining general acceptance, despite some remaining problems at certain points, notably the so-called [[100,000-year problem]]. For relatively recent periods data from [[radiocarbon]] dating and [[dendrochronology]] also support the MIS data.<ref>Aitken & Stokes (1997), 12–13; Wright, 431–432</ref> The sediments also acquire [[Rock magnetism#Depositional remanent magnetization (DRM)|depositional remanent magnetization]] which allows them to be correlated with earth's [[geomagnetic reversal]]s. For older core samples, individual annual depositions cannot usually be distinguished, and dating is taken from the geomagnetic information in the cores.<ref>Aitken & Stokes (1997), 10; Wright, 431</ref> Other information, especially as to the ratios of gases such as [[carbon dioxide]] in the atmosphere, is provided by analysis of [[ice core]]s.
The {{vanchor|SPECMAP}} Project, funded by the US [[National Science Foundation]], has produced one standard chronology for [[oxygen isotope]] records, although there are others. This high resolution chronology was derived from several isotopic records, the composite curve was then smoothed, filtered and tuned to the known cycles of the astronomical variables. The use of a number of isotopic profiles was designed to eliminate 'noise' errors, that could have been contained within a single isotopic record.<ref>[https://web.archive.org/web/20041118000935/http://gcmd.nasa.gov/records/GCMD_EARTH_LAND_NGDC_PALEOCL_SPECMAP.html SPECMAP on NASA website]</ref> Another large research project funded by the US government in the 1970s and 1980s was [[Climate: Long range Investigation, Mapping, and Prediction]] (CLIMAP), which to a large degree succeeded in its aim of producing a map of the global climate at the [[Last Glacial Maximum]], some 18,000 years ago, with some of the research also directed at the climate some 120,000 years ago, during the last interglacial. The theoretical advances and greatly improved data available by the 1970s enabled a "grand synthesis" to be made, best known from the 1976 paper ''Variations in the earth’s orbit: pacemaker of the ice ages'' (in ''[[Science (journal)|Science]]''), by J.D. Hays, Shackleton and [[John Imbrie]], which is still widely accepted, and covers the MIS timescale and the causal effect of the orbital theory.<ref>Cronin, 121–122, 121 quoted; [http://www.mantleplumes.org/WebDocuments/Hays1976.pdf PDF of paper] ''Variations in the earth’s orbit: pacemaker of the ice ages'' (in ''[[Science (journal)|Science]]''), by Shackleton and others</ref>
In 2010 the Subcommission on Quaternary Stratigraphy of the [[International Commission on Stratigraphy]] dropped other lists of MIS dates and started using the Lisiecki & Raymo (2005) LR04 Benthic Stack, as updated. This was compiled by [[Lorraine Lisiecki]] and [[Maureen Raymo]].<ref>{{cite web|url=https://quaternary.stratigraphy.org/correlation/chart.html|title=Version history of the Quaternary chronostratigraphical chart|year=2011|publisher=The Subcommission on Quaternary Stratigraphy}}</ref>
==Stages== {{further|Timeline of glaciation#Uncertain correlations}} [[File:Ocean core sediments on the Polarstern.jpg|thumb|Marine core sections from the South Atlantic, about a million years old]] The following are the start dates (apart from MIS 5 sub-stages) of the most recent MIS (Lisiecki & Raymo 2005, [[Lorraine Lisiecki#LR04 Benthic Stack (Lisiecki and Raymo, 2005)|LR04 Benthic Stack]]). The figures, in thousands of years ago, are from Lisiecki's website.<ref>{{cite journal|doi=10.1029/2004PA001071|url=https://archimer.ifremer.fr/doc/00233/34403/32830.pdf|title=A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records|journal=Paleoceanography|volume=20|author1= Lisiecki, Lorraine E.| author2= Raymo, Maureen E.|authorlink = Lorraine Lisiecki|authorlink2 = Maureen Raymo|year=2005|issue=1|pages=n/a|bibcode=2005PalOc..20.1003L|hdl=2027.42/149224|s2cid=12788441 |hdl-access=free}}</ref> Numbers for substages in MIS 5 denote peaks of substages rather than boundaries. <!-- If LOCAL NAMES ARE ADDED, PLEASE LOCATE THEM! -->
:'''MIS Start date'''
*MIS 1 – 14 kya, end of the [[Younger Dryas]] marks the start of the [[Holocene]]. The LR04 date of 14 kya had to accommodate less well studied time intervals, and the generally accepted date of 11.7 kya is to be preferred.<ref>Email from Lorraine Lisiecki</ref> *MIS 2 – 29 ([[Last Glacial Maximum]]) *MIS 3 – 57{{efn|Pettitt and White date MIS 3 as 59,000 to 24,000 BP. They say: "In the terrestrial record, five non forested MIS3 interstadials have been identified from Dutch and German organic deposits, from oldest to youngest the Oerel, Glinde, Moershoofd/Moershoofd Complex, Hengelo (c. 39,000 – c. 36,000 years BP) and Denekamp (c. 32,000 – c. 28,000 years BP) interstadials. In Britain only one interstadial has been identified (as of 2012), the Upton-Warren (c. 44,000 – c. 42,000 years BP).<ref>Pettitt and White, pp. 294, 296, 374</ref>}} (MIS 5d- MIS 2 is called the [[Last Glacial Period]], [[Wisconsinan glaciation]] in North America, [[Weichselian glaciation]] in northern Europe) *MIS 4 – 71 *[[MIS 5]] – 130, usually sub-divided into a to e: **MIS 5a – 82 (peak of interglacial sub-stage) **MIS 5b – 87 (peak of glacial sub-stage) **MIS 5c – 96 (peak of interglacial sub-stage) **MIS 5d – 109 (peak of glacial sub-stage) **MIS 5e – 123 (peak of [[Last Interglacial]], also known as the Eemian among other names) *MIS 6 – 191 ([[Penultimate Glacial Period]], also called [[Illinoian (stage)|Illinoian glacial]] in North America, later [[Saalian]] in northern Europe and later [[Wolstonian]] in Britain) *MIS 7 – 243 (Aveley Interglacial in Britain) *MIS 8 – 300 (early [[Wolstonian]] in Britain) *[[MIS 9]] – 337 ([[Purfleet Interglacial]] in Britain)<ref>Pettitt and White, p. 106</ref> *MIS 10 – 374 *[[Marine Isotope Stage 11|MIS 11]] – 424 ([[Hoxnian Stage|Hoxnian Interglacial]] in Britain, and [[Holstein Interglacial]] in Central Europe) *MIS 12 – 478 ([[Anglian (stage)|Anglian Glacial]] in Britain, [[Elster glaciation]] in northern Europe) *[[MIS13|MIS 13]] – 524 *MIS 14 – 563 *MIS 15 – 621 *[[MIS 16]] – 676 *MIS 17 – 712 *MIS 18 – 761 *MIS 19 – 790 ([[Brunhes–Matuyama reversal]]) *MIS 20 – 814 *MIS 21 – 866
The list continues to MIS 104, beginning 2.614 million years ago.
==Older versions== The following are the ''start dates'' of the most recent MIS, in [[Year#Abbreviations yr and ya|kya]] (thousands of years ago). The first figures are derived by Aitken & Stokes from Bassinot et al. (1994), with the figures in parentheses alternative estimates from Martinson et al. for stage 4 and for the others the SPECMAP figures in Imbrie et al. (1984). For stages 1–16 the SPECMAP figures are within 5 kya of the figures given here. All figures up to MIS 21 are taken from Aitken & Stokes, Table 1.4, except for the sub-stages of MIS 5, which are from Wright's Table 1.1.<ref>Aitken & Stokes (1997), p. 14; Wright, p. 6</ref>
*MIS 1 – 11 kya, end of the [[Younger Dryas]] marks the start of the [[Holocene]], continuing to the present *MIS 2 – 24 near [[Last Glacial Maximum]] *MIS 3 – 60 *MIS 4 – 71 (74) *MIS 5 – 130, includes the [[Eemian]]; usually sub-divided into a to 5e: **MIS 5a – 84.74 **MIS 5b – 92.84 **MIS 5c – 105.92 **MIS 5d – 115.105 **MIS 5e – 130.115 *MIS 6 – 190 *MIS 7 – 244 *MIS 8 – 301 *MIS 9 – 334 *MIS 10 – 364 *[[MIS 11]] 427, the most similar to MIS 1. *MIS 12 – 474 *[[MIS13|MIS 13]] – 528 *MIS 14 – 568 *MIS 15 – 621 *MIS 16 – 659 *MIS 17 – 712 (689) *MIS 18 – 760 (726) *MIS 19 – 787 (736) *MIS 20 – 810 (763) *MIS 21 – 865 (790)
Some older stages, in mya (millions of years ago):<ref>all (MIS 22, 62, 103) from "Concise", figs 15.6 and 15.7</ref> *MIS 22 – 1.03 mya, marking the end of the [[Bavelian]] period in Europe *MIS 62 – 1.75, end of the [[Tiglian]] *MIS 103 – 2.588, end of the [[Pliocene]] and start of the [[Pleistocene]], on the [[INQUA]] time scale (older definitions put this change at 1.806 mya – the MIS date is unaffected)
==See also== * [[Timeline of glaciation]] * [[Geologic temperature record]] * [[Paleothermometer]] * [[Anthropocene]] * [[Marine terrace]] * [[Ice core]]
==Notes== {{notelist}}
==Citations== {{reflist|2}}
==References== * Aitken, Martin J and Stokes, Stephen, in Taylor, Royal Ervin Taylor and Aitken, Martin Jim (eds), ''Chronometric dating in archaeology'', Chapter 1, 1997, Birkhäuser, {{ISBN|0-306-45715-6}}, {{ISBN|978-0-306-45715-9}}, [https://books.google.com/books?id=igeVNzJkpHMC&dq=marine+isotope+stage+archaeology&pg=PA12 google books] *{{cite book |last1=Andrews |first1=John T. |chapter=Dating Glacial Events and Correlation to Global Climate Change |title=Quaternary Geochronology: Methods and Applications |series=AGU Reference Shelf |editor1=Jay Stratton Noller |editor2=Janet M. Sowers |editor3=William R. Lettis |publisher=American Geophysical Union |date=2000 |pages=447–455 |chapter-url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/RF004p0447 |url=https://agupubs.onlinelibrary.wiley.com/doi/book/10.1029/RF004 |doi=10.1029/RF004p0447 |isbn=978-1-118-66848-1 }} {{ISBN|0-87590-950-7}}, {{ISBN|978-0-87590-950-9}} * "Concise", Ogg, James George, Ogg, Gabi, Gradstein F. M., ''The Concise Geologic Time Scale'', 2008, Cambridge University Press, 2008, {{ISBN|0-521-89849-8}}, {{ISBN|978-0-521-89849-2}} * Cronin, Thomas M., ''Paleoclimates: understanding climate change past and present'', Columbia University Press, 2010, {{ISBN|0-231-14494-6}}, {{ISBN|978-0-231-14494-0}}, [https://books.google.com/books?id=X49VC6B65DEC&dq=MIS+Emiliani+Shackleton&pg=PT144 google books] *{{cite book|title=The British Palaeolithic: Human Societies at the Edge of the Pleistocene World|first1=Paul|last1=Pettit|first2=Mark|last2=White|publisher=Routledge|year=2012|location=Abingdon, UK|isbn=978-0-415-67455-3}} * {{cite book |last1=Sowers |first1=Janet M. |chapter=Correlating Quaternary Landforms and Deposits to Global Climate Change |title=Quaternary Geochronology: Methods and Applications |series=AGU Reference Shelf |editor1=Jay Stratton Noller |editor2=Janet M. Sowers |editor3=William R. Lettis |publisher=American Geophysical Union |date=2000 |pages=425–426 |chapter-url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/RF004p0425 |url=https://agupubs.onlinelibrary.wiley.com/doi/book/10.1029/RF004 |doi=10.1029/RF004p0425 |isbn=978-1-118-66848-1 }} {{ISBN|0-87590-950-7}}, {{ISBN|978-0-87590-950-9}} * {{cite book |last1=Wright |first1=James D. |chapter=Global Climate Change in Marine Stable Isotope Records |title=Quaternary Geochronology: Methods and Applications |series=AGU Reference Shelf |editor1=Jay Stratton Noller |editor2=Janet M. Sowers |editor3=William R. Lettis |publisher=American Geophysical Union |date=2000 |pages=427–433 |chapter-url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/RF004p0427 |url=https://agupubs.onlinelibrary.wiley.com/doi/book/10.1029/RF004 |doi=10.1029/RF004p0427 |isbn=978-1-118-66848-1 }} {{ISBN|0-87590-950-7}}, {{ISBN|978-0-87590-950-9}}
==Further reading== *Cohen, K.M. and Gibbard, P.L., [http://quaternary.stratigraphy.org/charts/ ''Global chronostratigraphical correlation table for the last 2.7 million years''] (updated version 2011), Subcommission on Quaternary Stratigraphy, International Commission on Stratigraphy: Cambridge.
==External links== * [https://web.archive.org/web/20160303183334/http://www.colorado.edu/geography/class_homepages/geog_5241_f09/media/Readings/shackletonetal.pdf Marine Isotope Substage 5e and the Eemian Interglacial], ''NJ Shackleton'', 2003 * [http://www.realclimate.org/index.php/archives/2005/11/650000-years-of-greenhouse-gas-concentrations 650,000 years of greenhouse gas concentrations], ''RealClimate'', 2005 * [https://web.archive.org/web/20120309153706/http://www.people.fas.harvard.edu/~phuybers/Doc/progression_qsr2007.pdf Glacial variability over the last two million years], ''P Huybers'', 2007 * [http://www.cprm.gov.br/33IGC/1342754.html The polar paleoclimate signature of Marine Isotope Stage 31], ''Reed Scherer'', 2007 * [http://www.nature.com/ngeo/journal/v2/n6/full/ngeo527.html Oceanic forcing of the Marine Isotope Stage 11 interglacial], ''Alexander J. Dickson, Christopher J. Beer, Ciara Dempsey, Mark A. Maslin, James A. Bendle, Erin L. McClymont & Richard D. Pancost'', 2009 * [https://web.archive.org/web/20100704031655/http://newsroom.ucla.edu/portal/ucla/last-time-carbon-dioxide-levels-111074.aspx Last Time Carbon Dioxide Levels Were This High: 15 Million Years Ago], ''Aradhna Tripati'', 2009 *[http://www.ncdc.noaa.gov/paleo/paleocean.html US NCDC] *[https://web.archive.org/web/20041118000935/http://gcmd.nasa.gov/records/GCMD_EARTH_LAND_NGDC_PALEOCL_SPECMAP.html NASA SPECMAP] *[http://www.stratigraphy.org/upload/QuaternaryChart1.JPG Global chronostratigraphical correlation table for the last 2.7 million years, v.2010, International Commission on Stratigraphy]
[[Category:Dating methods]] [[Category:Marine isotope stages| *]] [[Category:Glaciology]] [[Category:Paleoclimatology]] [[Category:Stratigraphy]]