01:460:110 Lecture Notes - Lecture 12: Milankovitch Cycles
Document Summary
Find corals in more tropical areas rather than in upper and lower latitudes. Oxygen levels about ice vs no ice rather than higher and lower. Higher delta o 18 means more ice temperatures. Less delta o 18 means less ice. Can know early temperature records from tree rings, oxygen isotopes. Mideval warm period is about the same as the 20th century average. The little ice age is not 2 c colder than the average 20th century. It was cold enough to free new york harbor, washington at valley. The earth wobbles slightly on its axis, it precesses like a top. Today the rotation pole points to polaris, the north star. Very slight effect with how close earth is to the sun. Closest approach to the sun is december 21. 11,000 years ago, closest approach to the sun was june 21st.