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Why should a geologist be studying climate?. What defines INTERVALS on geologic timescale?

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Presentation on theme: "Why should a geologist be studying climate?. What defines INTERVALS on geologic timescale?"— Presentation transcript:

1 Why should a geologist be studying climate?

2 What defines INTERVALS on geologic timescale?

3 What defines BOUNDARIES on geologic timescale?

4 What causes ALL mass extinction events?

5 CLIMATE CHANGE is responsible for the organization of the geologic timescale

6 What are the (non-human) drivers of climate change?

7 What do these striations result from?

8 Would glacial striations form in an environment like this?

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12 Glacial remnants in Africa are explained by: 1) plate tectonics

13 Where do you find palm fronds today? Fossil palm frond

14 Where do you find palm fronds today? Hawaii

15 Bahamas

16 Wyoming?

17 Where would you expect to find alligators today?

18 Everglades

19 China

20 Ellesmere Island?

21 Alligator fossils found on Ellesmere Island 78° North (north of Greenland) 54.8-33.7 Mya Eocene Ellesmere Island?

22 Fossil palm fronds from Eocene (54.8-33.7 Mya) in Wyoming Did plate tectonics cause this?

23 Have the positions of Wyoming and Ellesmere changed much over the last 40 Mya?

24 Fossil palm fronds from Eocene (54.8-33.7 Mya) in Wyoming NOT caused by plate tectonics

25 What was going on here to change global temperature? Could we have alligators in the Arctic again?

26 What else besides plate tectonics can cause climate changes over long timescales?

27 2) Solar Forcing Variability

28 What causes the “eccentricity” of Earth’s orbit

29 Gravitational interactions with the orbits of Jupiter and Saturn

30 What is the period of Earth’s eccentricity?

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32 What familiar climate phenomenon does Earth’s “obliquity” cause?

33 Seasonality results from Earth’s obliquity

34 What is the period of Earth’s obliquity?

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36 “Precession” of the equinoxes occurs due to tidal forces from Sun and Moon

37 What is the period of Earth’s precession?

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39 Combined solar forcing is known as “Milankovitch cycles” 1920

40 Deep sea sediments record Milankovitch cycles over 500 Kya

41 Milankovitch cycles influence glacial cycles

42 How have glacial cycles changed over last 1000 Kya?

43 What else besides: 1)plate tectonics 2)orbital changes 3)…? can cause natural climate changes?

44 3) Variations in solar intensity …sunpot activity

45 NATURAL causes of global climate change: 1)plate tectonics 2)orbital changes 3)solar intensity

46 Earth’s climate system has great complexity

47 Earth’s Climate Components Simplified 5-part system

48 Earth’s Climate Components – Simplified Cause and Effect ~ “Forcing and Response” 1 2 3

49 Earth’s Climate Components – The Human Factor 1 2 3 4

50 Forcing: Factors that drive or cause change.

51 Forcing: Factors that drive or cause change. Response: A system reacting to a change in forcing.

52 Forcing: Factors that drive or cause change. Response: A system reacting to a change in forcing. Lag Time: The time it takes a system to react completely to a change in forcing.

53 Speed of Forcing Speed of Response How quickly does climate react?

54 Speed of Forcing Speed of Response 100’s of millions of yrs 40,000- 100,000 yrs 10,000s of yrs Decades to Centuries Hours to Weeks Hours to 10,000 yrs Hours to Centuries Days to 1,500 yrs Hours to Months?????????

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56 Forcing Response 100’s of millions of yrs 40,000- 100,000 yrs 10,000s of yrs Decades to Centuries Hours to Weeks Hours to 10,000 yrs Hours to Centuries Days to 1,500 yrs Hours to Months?????????


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