Marine isotope stages over the past 700,000 years

The history of Earth’s glacial and interglacial periods for the last 700 thousand years is reflected in the variation of oxygen isotope composition of marine sediments. The different glacial-interglacial cycles are called marine isotope stages and are numbered from young to old. The vertical red lines mark dated volcanic eruptions in Yellowstone. LGM and PGM stand for Last Glacial Maximum and Penultimate Glacial Maximum. The figure was modified from an original figure by Railsback and others published in in the journal Quaternary Science Reviews.