Quaternary glaciationThe Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began around 2.58 million years ago and is ongoing. Although geologists describe this entire period up to the present as an "ice age", in popular culture this term usually refers to the most recent glacial period, or to the Pleistocene epoch in general.
Late Cenozoic Ice AgeThe Late Cenozoic Ice Age, or Antarctic Glaciation, began 34 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets. Six million years after the start of the Late Cenozoic Ice Age, the East Antarctic Ice Sheet had formed, and 14 million years ago it had reached its current extent.
InterglacialAn 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.
Last InterglacialThe Last Interglacial was the interglacial period that 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. It was the second-to-latest interglacial of the current Ice Age, the most recent being the Holocene which extends to the present day (having followed the Last Glacial Period).
QuaternarySubdivision of the Quaternary according to the ICS, as of 2024.Vertical axis scale: Millions of years agoEtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitPeriodStratigraphic unitSystemTime span formalityFormalLower boundary definitionBase of magnetic polarity chronozone C2r (Matuyama)Extinction of the HaptophytesDiscoaster pentaradiatus and Discoaster surculusLower boundary GSSPMonte San Nicola Section, Gela, Sicily, Italy37°08′49″N14°12′13″E / 37.1469°N 14.2035°E / 37.1469; 14.2035Lower GSSP ratified2009 (as base of Quaternary and Pleistocene)Upper boundary definitionPresent dayUpper boundary GSSPN/AUpper GSSP ratifiedN/AAtmospheric and climatic dataMean atmospheric O2 contentc.
PleistoceneFirst epoch of the Quaternary PeriodSubdivision of the Quaternary according to the ICS, as of 2024.Vertical axis scale: Millions of years agoEtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)DefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionBase of magnetic polarity chronozone C2r (Matuyama).Extinction of the haptophytesDiscoaster pentaradiatus and Discoaster surculusLower boundary GSSPMonte San Nicola Section, Gela, Sicily, Italy37°08′49″N14°12′13″E / 37.1469°N 14.2035°E / 37.1469; 14.2035Lower GSSP ratified2009 (as base of Quaternary and Pleistocene)Upper boundary definitionEnd of the Younger DryasstadialUpper boundary GSSPNGRIP2 ice core, Greenland75°06′00″N42°19′12″W / 75.1000°N 42.3200°W / 75.1000; -42.3200Upper GSSP ratified2008 (as base of Holocene)The Pleistocene ( ; referred to colloquially as the Ice Age) is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations.
Antarctic ice sheetThe Antarctic ice sheet is a continental glacier covering 98% of the Antarcticcontinent, with an area of 14 million square kilometres (5.4 million square miles) and an average thickness of over 2 kilometres (1.2 mi). It is the largest of Earth's two current ice sheets, containing 26.5 million cubic kilometres (6,400,000 cubic miles) of ice, which is equivalent to 61% of all fresh water on Earth.
HoloceneCurrent geological epochSubdivision of the Holocene according to the ICS, as of 2024.Vertical axis scale: Gregorian yearsEtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEpochStratigraphic unitSeriesTime span formalityFormalLower boundary definitionEnd of the Younger Dryasstadial.Lower boundary GSSPNGRIP2 ice core, Greenland75°06′00″N42°19′12″W / 75.1000°N 42.3200°W / 75.1000; -42.3200Lower GSSP ratified2008Upper boundary definitionPresent dayUpper boundary GSSPN/AN/AUpper GSSP ratifiedN/AThe Holocene () is the current geological epoch, beginning approximately 11,700 years ago.
Eocene–Oligocene extinction eventThe Eocene–Oligocene extinction event, also called the Eocene-Oligocene transition (EOT), is the transition between the end of the Eocene and the beginning of the Oligocene, an extinction event and occurred from around 33.9 to 33.4 million years ago. It was marked by large-scale extinction and floral and faunal turnover, although it was relatively minor in comparison to the largest mass extinctions.
CenozoicEtymologyName formalityFormalNickname(s)Age of MammalsUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitEraStratigraphic unitErathemTime span formalityFormalLower boundary definitionIridium enriched layer associated with a major meteorite impact and subsequent K-Pg extinction event.Lower boundary GSSPEl Kef Section, El Kef, Tunisia36°09′13″N8°38′55″E / 36.1537°N 8.6486°E / 36.1537; 8.6486Lower GSSP ratified1991Upper boundary definitionN/AUpper boundary GSSPN/AUpper GSSP ratifiedN/AThe Cenozoic Era (also known as the Caenozoic, Kainozoic, or Neozoic Era; ; ; lit.'new life') is Earth's current geological era, representing the last 66million years of Earth's history.
Late PleistoceneThe Late Pleistocene is an unofficial age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently defined as the time between c. 129,000 and c. 11,700 years ago.
Arctic ice packThe Arctic ice pack is the sea ice cover of the Arctic Ocean and its vicinity. The Arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer, reaches a minimum around mid-September, then increases during autumn and winter. Summer ice cover in the Arctic is about 50% of winter cover. Some of the ice survives from one year to the next.*As an Amazon Associate I earn from qualifying purchases.