thumb|350x350px|Map of glacial cycles from 600-100,000 years ago, with MIS 9 labelled '''Marine Isotope Stage 9''' ('''MIS 9''') was an interglacial (warm) Marine Isotope Stage. It was the last period of the Lower Paleolithic.<ref name=flake>{{cite journal| last= Rawlinson|first=Aaron |display-authors=etal| journal= Journal of Human Evolution|title=Flake tools in the European Lower Paleolithic: A case study from MIS 9 Britain|volume=165 |number= |url= https://www.sciencedirect.com/science/article/abs/pii/S0047248422000136|doi= 10.1016/j.jhevol.2022.103153|date=April 2022 |article-number=103153 |issn= }}</ref> Estimates of its dating vary. It lasted from 337,000 to 300,000 years ago according to Lisiecki and Raymo's 2005 LR04 Benthic Stack,<ref>{{Cite journal |last1=Lisiecki |first1=Lorraine E. |last2=Raymo |first2=Maureen E. |date=18 January 2005 |title=A Pliocene-Pleistocene stack of 57 globally distributed benthic δ<sup>18</sup>O records |url=http://dx.doi.org/10.1029/2004pa001071 |journal=Paleoceanography |volume=20 |issue=1 |pages=n/a |doi=10.1029/2004pa001071 |bibcode=2005PalOc..20.1003L |s2cid=12788441 |issn=0883-8305}}</ref> whereas Rawlinson et al dated it in 2022 to between 328,000 and 301,000 years ago.<ref name=flake/>
Views on its division into sub-stages also vary. A 2013 study divided it into two warm interstadials (9a and 9c) and one cooler stadial (9b),<ref name=":0">{{Citation |last=Webb |first=Steve |title=6 - Australia and the Quaternary Ice Ages |date=2013-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780124077904000069 |work=Corridors to Extinction and the Australian Megafauna |pages=127–148 |editor-last=Webb |editor-first=Steve |place=Oxford |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-407790-4.00006-9 |isbn=978-0-12-407790-4 |access-date=2023-02-13|url-access=subscription }}</ref><ref>{{Citation |last=Webb |first=Steve |title=Australia's Megafauna Extinction Drivers |date=2013 |url=http://dx.doi.org/10.1016/b978-0-12-407790-4.00009-4 |work=Corridors to Extinction and the Australian Megafauna |pages=217–242 |access-date=2023-02-05 |publisher=Elsevier|doi=10.1016/b978-0-12-407790-4.00009-4 |isbn=9780124077904 |url-access=subscription }}</ref> whereas a 2025 study had three warm sub-stages (9a, 9c and 9e) and two which were cooler (9b and 9d).<ref>{{cite journal| last= Jia|first=Wei |display-authors=etal| journal= Quaternary Science Reviews|title=Hydroclimate variability in southwest China during Marine Isotope Stage 9: Insights from multi–proxy stalagmite records|volume= 355|number= |url= https://www.sciencedirect.com/science/article/abs/pii/S0277379125000885|doi= 10.1016/j.quascirev.2025.109268|date=1 May 2025 |article-number=109268 |issn= |url-access= subscription}}</ref>
In Great Britain, it is known as the '''Purfleet Interglacial'''.<ref>{{Cite journal |last=Rawlinson |first=Aaron |last2=Davis |first2=Rob |last3=Ashton |first3=Nick |last4=Bridgland |first4=David |last5=Dale |first5=Luke |last6=Lewis |first6=Simon |last7=White |first7=Mark |date=2025-05-17 |title=The Occurrence of Non-handaxe Assemblages Early in the Purfleet Interglacial (MIS 9) in Britain |url=https://link.springer.com/10.1007/s41982-025-00217-2 |journal=Journal of Paleolithic Archaeology |language=en |volume=8 |issue=1 |doi=10.1007/s41982-025-00217-2 |issn=2520-8217 |pmc=12085398 |pmid=40391316}}</ref>
== MIS Drivers == Marine Isotope Stages are glacial and interglacial periods throughout time.<ref name=":2">{{Cite book |last=Cronin |first= Thomas |title=Paleoclimates understanding climate change past and present |date=2010 |publisher=Columbia University Press |isbn=978-0-231-51636-5 |oclc=1303291501}}</ref> One of the processes that drive this major change are the Milankovitch Cycles, which control the insolation received from the Sun. <ref>{{Cite journal |last1=Stirling |first1=C. H. |last2=Esat |first2=T. M. |last3=Lambeck |first3=K. |last4=McCulloch |first4=M. T. |last5=Blake |first5=S. G. |last6=Lee |first6=D.-C. |last7=Halliday |first7=A. N. |date=2001-01-12 |title=Orbital Forcing of the Marine Isotope Stage 9 Interglacial |url=https://www.science.org/doi/10.1126/science.291.5502.290 |journal=Science |language=en |volume=291 |issue=5502 |pages=290–293 |doi=10.1126/science.291.5502.290 |pmid=11209076 |bibcode=2001Sci...291..290S |issn=0036-8075|url-access=subscription }}</ref> The data is retrieved from deep sea core samples. The manner by which the data is obtained through core samples is mainly due to the sedimentation in the region which can be very indicative of an interglacial or glacial phases.
=== Marine Oxygen Isotopes === thumb|Changes in oxygen isotopes ratios during glacial and interglacial events. MIS are obtained through oxygen isotope analysis within the core samples to understand paleoclimate changes. <ref name=":2" /> This includes glacial and interglacial periods. The data is retrieved from proxies, such as foraminifera and pollen that have diverse oxygen-18 to oxygen-16 ratios depending on the temperature in the ocean during said events. When the isotopic analysis results in high isotopic ratio values, it is representative of colder glacial environments, while isotopic values with low ratios are indicative of warmer temperatures.<ref>{{Cite book |first=Marcel |last=Brannemann|display-authors=etal|title=Cool libraries in a melting world : proceedings of the 23rd Polar Libraries Colloquy 2010, June 13-18, 2010, Bremerhaven, Germany |date=2010 |publisher=AWI, Alfred-Wegener-Institut für Polar- und Meeresforschung |oclc=1064296475}}</ref>
== Interglacial Impacts on Living Organisms ==
=== European culture impacts === During this interglacial stage, Europe was occupied by ''Homo heidelbergensis'', who had retreated from Britain during the preceding glacial period. Populations returned as the climate warmed and sea levels rose around 330,000 years ago. The evidence of their return is found along terraces of the Thames and former Solent rivers of Europe. Within the area, thousands of hand axes and other artefacts have been found indicating their return after the increasing warmer temperatures. In Southern England, the summers were similar to or slightly warmer than today, and the winters slightly cooler.<ref>{{Cite book |last=Ashton |first=Nick |title=Early humans |date=2017 |isbn=978-0-00-815035-8 |location=London|publisher=William Collins |oclc=959648563 }}{{pn|date=February 2026}}</ref> The period saw a transition to Clactonian culture for manufacture of stone tools.<ref>{{Cite book |last=McNabb |first=John |url=https://books.google.com/books?id=9g1tpFlQCYQC&q=%22Purfleet+Interglacial%22&pg=PA162 |title=The British Lower Palaeolithic: Stones in Contention |date=2011-03-17 |publisher=Routledge |isbn=978-1-134-09055-6 |language=en}}</ref>
==References== {{reflist}}
Category:Marine isotope stages Category:Interglacials