Marine Isotope Stages (MIS) are alternating warm and cold periods in Earth’s paleoclimate, determined by oxygen isotope ratios in marine sediment cores. These stages are important for understanding past climate changes, glacial-interglacial cycles, and the timing of climatic events.
Reference: Imbrie, J., et al. (1984). “The Orbital Theory of Pleistocene Climate: Support from a Revised Chronology of the Marine δ18O Record.” In: Milankovitch and Climate. Springer, pp. 269-305.