MIS/OIS Marine Isotopic Stages

Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS) are alternating warm and cool periods in the Earth’s paleoclimate, deducted from oxygen isotope data derived from deep sea core samples.

Working backwards from the present, MIS 1 in the scale, stages with even numbers have high levels of O18 and represents cold glacial periods, while the odd numbered stages are thought in the low level of O18 representing warm interglacial intervals.

The data are derived from Pollen and Foraminifera remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate, called proxies.

• The cycles in the isotope ratio were found to correspond to terrestrial evidence of glacial and interglacial, A graph of the entire series of stages than reveled unsuspected advances and retreats of ice and also filled in the details of the Stadial and Interstadials.
• The MIS data also matches the astronomical data of Milankovitch cycles of orbital forcing or the effects of variations in insolation caused by cyclical changes in the tilt of Earth’s axis of rotation –The orbital theory.
• For relatively recent period data from radiocarbon dating and dendrochronology also supports the MIS data.

REFERENCES :-

• https://en-academic.com/dic.nsf/enwiki/11697432
• Recent Indian studies in Himalayan Cryosphere
• L. Bruce Railsback, March 2015, An optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages
• Lecture notes of University of Lucknow