Timeline of glaciation

Climate history over the past 500 million years, with the last three major ice ages indicated, Andean-Saharan (450 Ma), Karoo (300 Ma) and Late Cenozoic. A less severe cold period or ice age is shown during the Jurassic-Cretaceous (150 Ma).

There have been five or six major ice ages in the history of Earth over the past 3 billion years. The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago.

Within ice ages, there exist periods of more severe glacial conditions and more temperate conditions, referred to as glacial periods and interglacial periods, respectively. The Earth is currently in such an interglacial period of the Quaternary glaciation, with the Last Glacial Period of the Quaternary having ended approximately 11,700 years ago. The current interglacial is known as the Holocene epoch. Based on climate proxies, paleoclimatologists study the different climate states originating from glaciation.

Known ice ages

Major known ice ages shown in blue.

Name of ice age Years BP (Ma) Geological period Era
Pongola 2900–2780 Mesoarchean
Huronian 2400–2100 Siderian
Rhyacian
Paleoproterozoic
Sturtian
Marinoan
Gaskiers
Baykonur
715–680
650–635
580
547
Cryogenian

Ediacaran
Neoproterozoic
Andean-Saharan
(incl. Hirnantian and
Late Ordovician glaciation)
450–420 Late Ordovician
Silurian
Paleozoic
Karoo 360–289 Carboniferous
Permian
Paleozoic
Late Cenozoic Ice Age
(incl. Quaternary glaciation)
34–present Late Paleogene
Neogene
Quaternary
Cenozoic

Descriptions

The third ice age, and possibly most severe, is estimated to have occurred from 720 to 635 Ma (million years) ago, in the Neoproterozoic Era, and it has been suggested that it produced a second "Snowball Earth", i.e. a period during which Earth was completely covered in ice. It has also been suggested that the end of that second cold period was responsible for the subsequent Cambrian explosion, a time of rapid diversification of multi-cellular life during the Cambrian Period. The hypothesis is still controversial, though is gaining credence among researchers, as evidence in its favour has mounted.[citation needed]

A minor series of glaciations occurred from 460 to 430 Ma, and there were extensive glaciations from 350 to 289 Ma.

The Late Cenozoic Ice Age has seen extensive ice sheets in Antarctica for the last 34 Ma. During the last 3 Ma, ice sheets have also developed on the northern hemisphere. That phase is known as the Quaternary glaciation, and was marked by more or less extensive glaciation. They first appeared with a dominant frequency of 41,000 years, but after the Mid-Pleistocene Transition that changed to high-amplitude cycles, with an average period of 100,000 years.

Nomenclature of Quaternary glacial cycles

Whereas the first 30 million years of the Late Cenozoic Ice Age mostly involved Antarctica, the Quaternary has seen numerous ice sheets extending over parts of Europe and North America that are currently populated and easily accessible. Early geologists therefore named apparent sequences of glacial and interglacial periods of the Quaternary Ice Age after characteristic geological features, and these names varied from region to region. The marine record preserves all the past glaciations; the land-based evidence is less complete because successive glaciations may wipe out evidence of their predecessors. Ice cores from continental ice accumulations also provide a complete record, but do not go as far back in time as marine data. Pollen data from lakes and bogs as well as loess profiles provided important land-based correlation data. The names system has mostly been phased out by professionals. It is now more common for researchers to refer to the periods by their marine isotopic stage number. For example, there are five Pleistocene glacial/interglacial cycles recorded in marine sediments during the last half million years, but only three classic glacials were originally recognized on land during that period (Mindel, Riss and Würm).

Land-based evidence works acceptably well back as far as MIS 6, but it has been difficult to coordinate stages using just land-based evidence before that. Hence, the "names" system is incomplete and the land-based identifications of ice ages previous to that are somewhat conjectural. Nonetheless, land based data is essentially useful in discussing landforms, and correlating the known marine isotopic stage with them.

Historical nomenclature in the Alps

Historical nomenclature in Great Britain and Ireland

Historical nomenclature in Northern Europe

Historical nomenclature in North America

Historical nomenclature in South America

Uncertain correlations

It has proved difficult to correlate the traditional regional names with the global marine and ice core sequences. The indexes of MIS often identify several distinct glaciations that overlap in time with a single traditional regional glaciation. Some modern authors use the traditional regional glacial names to identify such a sequence of glaciations, whereas others replace the word "glaciation" with "complex" to refer to a continuous period of time that also includes warmer stages. As shown in the table below, it is only during the last 200-300 thousand years that the time resolution of the traditional nomenclature allow for clear correspondence with MIS indexes. In particular there has been a lot of controversy regarding the glaciations MIS 10 and MIS 12, and their correspondence to the Elster and Mindel glaciations of Europe.

Marine
isotope
stage
Time ago
(ka)
Regional names Global
age /
epoch
Alpine region Great Britain N. Europe E. Europe N. America S. America
MIS 103-64 2600–1800 Biber Pre-Ludham
Ludham
Thurnian
Bramerton
Bavents
Paston
Pre-Tiglian
Tiglian A
Tiglian B
Tiglian C3
Tiglian C4
Tiglian C5
Verkhodon

Khapry
Pre-illinois K

Pre-illinois J
Gelasian
MIS 63-23 1800–900 Danube Beeston Eburon
Waal
Menap
Bavel
Tolucheevka

Krinitsa
Pre-illinois I
Pre-illinois H
Pre-illinois G
Calabrian
MIS 22 900–866 Günz Cromer Cromer Pre-illinois F
MIS 21 866–814 Günz Cromer Cromer Pre-illinois
MIS 20 814–790 Günz Cromer Cromer Pre-illinois E ?
MIS 19 790–761 Günz Cromer Cromer Pre-illinois Chibanian
MIS 18 761-712 Günz Cromer Cromer Pre-illinois E ?
MIS 17 712-676 Günz Cromer Cromer Pre-illinois
MIS 16 676–621 Günz Cromer Cromer/Don Don Pre-illinois D
MIS 15 621–563 Günz Cromer Cromer Muchkap Pre-illinois
MIS 14 563–533 Günz Cromer Cromer Oka? Pre-illinois C
MIS 13 533–478 Günz Cromer Cromer Oka? Pre-illinois
MIS 12 478–424 Günz Mindel? Anglia Elster Cromer? Oka Pre-illinois B Caracoles Río Frío?
MIS 11 424–374 Günz? Hoxne Holstein Cromer/Rhume? Likhvin Pre-illinois
MIS 10 374–337 Mindel? Wolston Elster? Likhvin? Pre-illinois A ? Río Llico Colegual?
MIS 9 337–300 Mindel-Riss? Wolston Purfleet Holstein? Likhvin Pre-illinois
MIS 8 300–243 Riss Wolston Saale/Fuhne AC Pre-illinois A ?
MIS 7 243–191 Riss Wolston Aveley Saale/Dömnitz Belvedere AC Pre-illinois
MIS 6 191–130 Riss Wolston Saale/Drenthe,Warthe Dnieper/Moscow Illinois Santa María Casma?
MIS 5e 123 (peak) Riss-Würm Ipswich Eem Mikulino Sangamonian Valdivia Late
Pleistocene


('Tarantian')
MIS 5d 109 (peak) Würm Devens/Early D. Weichsel/Herning Valdai AC AC
MIS 5c 96 (peak) Würm Devens/Early D. Weichsel/Brørup Valdai AC AC
MIS 5b 87 (peak) Würm Devens/Early D. Weichsel/Rederstall Valdai AC AC
MIS 5a 82 (peak) Würm Devens/Early D. Weichsel/Odderade Valdai AC AC
MIS 4 71–57 Würm Devens/Middle D. Weichsel/Middle W. Valdai Wisconsin Llanquihue
MIS 3 57–29 Würm Devens/Middle D. Weichsel/Middle W. Valdai Wisconsin Llanquihue
MIS 2 29–14 Würm/LGM Devens/Dimlington Weichsel/LGM Valdai Wisconsin/Vashon Llanquihue/LGM
MIS 1 14–present (Holocene) Flandria Flandria (Holocene) (Holocene) (Holocene) Holocene
Table explanation
Extensive interglacial (similar to Holocene)
Moderate interglacial
Intermediate climate
Moderate glaciation
Extensive glaciation (similar to LGM)
AC = Ambiguous correlation

Sources

For sources to the tables, see the individual linked articles.

See also


This page was last updated at 2024-02-22 10:15 UTC. Update now. View original page.

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