ESS101C
Prof.
Jin-Yi Yu
Evidence of Ice Sheet Evolution
qThis figures shows a North
Atlantic Ocean
sediment core holds a 3 Myr d18O record of
ice volume and deep-water temperature changes.
qThere were no major ice sheets
before 2.75 Myr
ago.
qAfter that, small ice sheets grew and melted at cycles of 41,000 and
23,000 years
until 0.9 Myr ago.
qAfter 0.9 Myr ago, large ice
sheet grew and melted
at a cycle of 100,000 years.
(from Earth’s Climate: Past and Future)