Glacial-Holocene deep-sea core record of ice-rafted debris, petrology,
and isotopes of the North Atlantic Ocean basin (from ref. 2, Fig. 6; BP
in kyr before A.D. 1950), which shows evidence of pervasive
millennial-scale fluctuations in climate. Overlaid in red are times of
peak forcing in the 1,800-year tidal cycle.