1. Ice Ages: Introduction to their Profound Impact on Planet Earth

2. Glaciers 1.Climatic Setting Ice Ages 2.Indirect Effects of Glaciers

3. 1. Climatic Setting of Glaciers Colder Warmer

4. Gradual Cooling into the Pleistocene - cause under debate

5. In the Pleistocene

7. Varves

13. But in last few centuries, changes in solar output caused the Little Ice Age and warming up since

14. Is it natural warming from the Little Ice Age? Or human- caused global warming? Explored later in this class

15. 2. Indirect Effects of Glaciers

16. Water moves back and forth between glaciers and oceans

18. “Noah’s Flood” hypothesis William Ryan & Walter Pittman (Columbia Controversial, not universally accepted, but intriguing

19. Coming out of last ice age ~7600 years ago (=5600 B.C.), sea level was low but rising –Why? Black Sea was freshwater, surrounded by farms

20. Noah’s Flood? Rising global sea level raised Mediterranean above the Bosporus Strait –Broke through natural dam –Water rose ~6 inches / day –Flooded lakeshore communities

21. some of the evidence Many cultures have a flood story, many can be traced to the Black Sea area Remains of houses & villages have been found on the pre- flood lakeshore But: New work finds no evidence for a sudden rise in water level of Black Sea.

22. 2. Indirect Effects of Glaciers: glacial loess

23. Loess in Alaska

27. Loess Plateau, China from glacial dust and desert dust

28. 2. Indirect Effects of Glaciers: paleolakes from changes in climate patterns

29. 2 shorelines of ancient lakes

31. 2. Many more indirect effects!