Marine Isotope Stages

Building A Paleoclimatic History of the World

Microscopic image of Calcareous phytoplankton
Science Photo Library / STEVE GSCHMEISSNER / Getty Images

Marine Isotope Stages (abbreviated MIS), sometimes referred to as Oxygen Isotope Stages (OIS), are the discovered pieces of a chronological listing of alternating cold and warm periods on our planet, going back to at least 2.6 million years. Developed by successive and collaborative work by pioneer paleoclimatologists Harold Urey, Cesare Emiliani, John Imbrie, Nicholas Shackleton, and a host of others, MIS uses the balance of oxygen isotopes in stacked fossil plankton (foraminifera) deposits on the bottom of the oceans to build an environmental history of our planet. The changing oxygen isotope ratios hold information about the presence of ice sheets, and thus planetary climate changes, on our earth's surface.

How Measuring Marine Isotope Stages Work

Scientists take sediment cores from the bottom of the ocean all over the world and then measure the ratio of Oxygen 16 to Oxygen 18 in the calcite shells of the foraminifera. Oxygen 16 is preferentially evaporated from the oceans, some of which falls as snow on continents. Times when snow and glacial ice buildup occur therefore see a corresponding enrichment of the oceans in Oxygen 18. Thus the O18/O16 ratio changes over time, mostly as a function of the volume of glacial ice on the planet.

Supporting evidence for the use of oxygen isotope ratios as proxies of climate change is reflected in the matching record of what scientists believe the reason for the changing amount of glacier ice on our planet. The primary reasons glacial ice varies on our planet was described by Serbian geophysicist and astronomer Milutin Milankovic (or Milankovitch) as the combination of the eccentricity of Earth's orbit around the sun, the tilt of the Earth's axis and the wobble of the planet bringing the northern latitudes nearer to or farther from the sun's orbit, all of which changes the distribution of incoming solar radiation to the planet.

Sorting Out Competing Factors

The problem is, however, that although scientists have been able to identify an extensive record of global ice volume changes through time, the exact amount of sea level rise, or temperature decline, or even ice volume, is not generally available through measurements of isotope balance, because these different factors are interrelated. However, sea level changes can sometimes be identified directly in the geological record: for example, datable cave encrustations which develop at sea levels (see Dorale and colleagues). This type of additional evidence ultimately helps sorts out the competing factors in establishing a more rigorous estimation of past temperature, sea level, or the amount of ice on the planet.

Climate Change on Earth

The following table lists a paleo-chronology of life on earth, including how the major cultural steps fit in, for the past 1 million years. Scholars have taken the MIS/OIS listing well beyond that.

Table of Marine Isotope Stages

MIS Stage Start Date Cooler or Warmer Cultural Events
MIS 1 11,600 warmer the Holocene
MIS 2 24,000 cooler last glacial maximum, Americas populated
MIS 3 60,000 warmer upper Paleolithic begins; Australia populated, upper Paleolithic cave walls painted, Neanderthals disappear
MIS 4 74,000 cooler Mt. Toba super-eruption
MIS 5 130,000 warmer early modern humans (EMH) leave Africa to colonize the world
MIS 5a 85,000 warmer Howieson's Poort/Still Bay complexes in southern Africa
MIS 5b 93,000 cooler
MIS 5c 106,000 warmer EMH at Skuhl and Qazfeh in Israel
MIS 5d 115,000 cooler
MIS 5e 130,000 warmer
MIS 6 190,000 cooler Middle Paleolithic begins, EMH evolves, at Bouri and Omo Kibish in Ethiopia
MIS 7 244,000 warmer
MIS 8 301,000 cooler
MIS 9 334,000 warmer
MIS 10 364,000 cooler Homo erectus at Diring Yuriahk in Siberia
MIS 11 427,000 warmer Neanderthals evolve in Europe. This stage is thought to be the most similar to MIS 1
MIS 12 474,000 cooler
MIS 13 528,000 warmer
MIS 14 568,000 cooler
MIS 15 621,000 ccooler
MIS 16 659,000 cooler
MIS 17 712,000 warmer H. erectus at Zhoukoudian in China
MIS 18 760,000 cooler
MIS 19 787,000 warmer
MIS 20 810,000 cooler H. erectus at Gesher Benot Ya'aqov in Israel
MIS 21 865,000 warmer
MIS 22 1,030,000 cooler

Sources

Jeffrey Dorale of the University of Iowa.

Bintanja , R. "North American ice-sheet dynamics and the onset of 100,000-year glacial cycles." Nature volume 454, R. S. W. van de Wal, Nature, August 14, 2008.

Bintanja, Richard. "Modelled atmospheric temperatures and global sea levels over the past million years." 437, Roderik S.W. van de Wal, Johannes Oerlemans, Nature, September 1, 2005.

Dorale JA, Onac BP, Fornós JJ, Ginés J, Ginés A, Tuccimei P, and Peate DW. 2010. Sea-Level Highstand 81,000 Years Ago in Mallorca. Science 327(5967):860-863.

Hodgson DA, Verleyen E, Squier AH, Sabbe K, Keely BJ, Saunders KM, and Vyverman W. 2006. Interglacial environments of coastal east Antarctica: comparison of MIS 1 (Holocene) and MIS 5e (Last Interglacial) lake-sediment records. Quaternary Science Reviews 25(1–2):179-197.

Kaiser J, and Lamy F. 2010. Links between Patagonian Ice Sheet fluctuations and Antarctic dust variability during the last glacial period (MIS 4-2). Quaternary Science Reviews 29(11–12):1464-1471.

Martinson DG, Pisias NG, Hays JD, Imbrie J, Moore Jr TC, and Shackleton NJ. 1987. Age dating and the orbital theory of the ice ages: Development of a high-resolution 0 to 300,000-year chronostratigraphy. Quaternary Research 27(1):1-29.

Suggate RP, and Almond PC. 2005. The Last Glacial Maximum (LGM) in western South Island, New Zealand: implications for the global LGM and MIS 2. Quaternary Science Reviews 24(16–17):1923-1940.