qAfter 0.9 Myr ago, the
41,000-year and 23,000-year cycles of ice volume change were overridden by larger and more
dominant fluctuations
of ice sheets at a period of 100,000 years.
qThe large 100,000-year cycle is
not related to any cycle of orbital variations.
qTWO QUESTIONS:
q (1) Why did more ice accumulate after 0.9 Myr ago?
q (2) Why did these large ice sheets melt rapidly every 100,000 years?