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Mastodons and Ice Ages Part 2: What killed the Megafauna at the end of the Last Ice Age?

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Presentation on theme: "Mastodons and Ice Ages Part 2: What killed the Megafauna at the end of the Last Ice Age?"— Presentation transcript:

1 Mastodons and Ice Ages Part 2: What killed the Megafauna at the end of the Last Ice Age?

2 Gate to the Pleistocene PastPresentFuture Tardis, from Dr. Who

3 North America Satellite view 12kya

4 South America Before & After From Quaternary Environmental Networks

5

6 Mastodon

7 Mastodon Distribution George H. Michaels and Brian M. Fagan, UC Santa Barbara

8 Wooly Mammoth

9 Mammoth Distribution George H. Michaels and Brian M. Fagan, UC Santa Barbara

10 Mammoth & Mastodon Teeth

11 Sabertooth Cat kids.com/science/biodiversity/extinction/R esourcesBestiaryFS.html

12 Smilodon Distribution

13 Steppe Bison

14 Yesterday’s Camel (Camelops)

15 American Horse

16 Dire Wolf

17 Macrauchenia patachonica

18 American Lion

19 North America ca 12kYa

20 Megatherium - Ground Sloth

21 Copyright 1997 Michael Rothman. This image is available for reuse American Cheetah and Pronghorn Antelope

22 Dwarf Pronghorn

23 Giant short-faced bears

24 Short-Faced Bear

25 Merriam’s Teratorn

26 Giant Beaver

27 Irish Elk Teichmann Collection

28 Glyptotherium texanum

29 Survivors of the Pleistocene

30 Caribou or Reindeer-

31 Muskox

32 Mountain Lion

33 Jaguar

34 Homo sapiens

35 Pleistocene Mystery What happened to all of the large animals 10-12,000 years ago?????? What happened to all of the large animals 10-12,000 years ago?????? They disappeared very quickly – within 400 years They disappeared very quickly – within 400 years Selected against largest animals – Megafauna went extinct Selected against largest animals – Megafauna went extinct

36 Modern Day Extinctions adapted from Nillson (1983) and UNESCO data

37 Most Common Causes of Modern Day Extinction Commercial Harvesting Commercial Harvesting Deforestation to Agricultural land Deforestation to Agricultural land Introduction of non-native species Introduction of non-native species

38 Extinction

39 Extinction

40 Over-Kill Human hunters killed all of these animals when they migrated into the North America

41 Over-Ill Human or human associated disease killed all of these animals Human or human associated disease killed all of these animals

42 Over-Chill: Abrupt Climate Change The cold dry climate of the late Glacial period changed to a warm-dry period with considerable effect on flora and fauna The cold dry climate of the late Glacial period changed to a warm-dry period with considerable effect on flora and fauna

43 Comet Strike A comet or meteor struck the Glacier A comet or meteor struck the Glacier

44 North America Before & After Tim Ball nsrp.org

45 Vegetation Vegetation General gradual movement of warm- adapted biomes north General gradual movement of warm- adapted biomes north Pollen records indicate spruce and oak moved north Pollen records indicate spruce and oak moved north Mid-glacial produced no- analog vegetation Mid-glacial produced no- analog vegetation Mixtures that do not exist today Mixtures that do not exist today Different response of a particular type of plant to changing climate Different response of a particular type of plant to changing climate

46 Examples of C3 & C4 Plants C3 C3 Trees Trees Winter Grass Winter Grass Shrubs Shrubs Forbs - Daffodils Forbs - Daffodils Algae & Phytoplankton Algae & Phytoplankton Fossil Fuels Fossil Fuels C4 C4 Crabgrass Crabgrass Maize Maize Sugarcane Sugarcane Sorghum Sorghum Switchgrass Switchgrass Sedges Sedges Modern Modern

47 Characteristics of C3 & C4 Plants C3 C3 85% Plant Species 85% Plant Species High in Protein High in Protein Good Browse Good Browse Less efficient Photosynthesis Less efficient Photosynthesis Optimal CO2 at 1000 ppm Atmosphere Optimal CO2 at 1000 ppm Atmosphere C4 C4 15% Plant Species 15% Plant Species Low Protein Low Protein High Silica High Silica Poor Browse Poor Browse Competes at Low CO2 Competes at Low CO2

48 C3 & C4 Plants

49 Rise of C4 Plants

50 Mastodons and Ice Ages Part 3: Glaciers and Ice ages

51 Glaciers & Ice Ages

52 Glaciers in Alaska

53 Glaciers are Dynamic Mountain Bed Rock Glacier Zone of Accumulation Zone of Ablation Terminus Equilibrium Line

54 Continental Glaciers Greenland & Antarctica Zone of Accumulation - Precipitation does not melt Zone of Ablation: Ocean calves Icebergs Glacier - Pushed to the sea through fjords Terminus GLACIER 4800m thick Bed Rock Sea Level Ocean Ocean Icebergs Colder Warmer Nunatuk

55 Greenland, Rates of ice sheet thinning in Greenland

56 Continental Glacier Growth

57 South America Before & After From Quaternary Environmental Networks

58 Biological Pump Brian N. Popp Professor/Associate Department Chair Dept. of Geology & Geophysics University of Hawaii

59 Hydrologic Budget www2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/bdgt.rxml

60 Precipitation & Carbon Turnover Atmosphere 730 Gt Atmosphere 730 Gt Earth Area (km 2 ) 510 x10 6 km 2 Earth Area (km 2 ) 510 x10 6 km 2 Square Meters/km 2 1,000,000 m 2 / km 2 Square Meters/km 2 1,000,000 m 2 / km 2 Total Precipitation423 x m 3 Total Precipitation423 x m 3 Average Precipitation/yr 0.83 m/yr Average Precipitation/yr 0.83 m/yr CO2 380 ppmv CO2 380 ppmv Henry’s Law Ratio (aq/gas) Henry’s Law Ratio (aq/gas) Mass CO2134 Gt Mass CO2134 Gt Mass C/CO212/44 Gt Mass C/CO212/44 Gt Mass C36.5 Gt Mass C36.5 Gt Turnover20 yrs Turnover20 yrs

61 CO 2 Tied up in Ice Age Glaciers Atmosphere 730 Gt Carbon Atmosphere 730 Gt Carbon Earth Area (km 2 ) 510 x10 6 km 2 Earth Area (km 2 ) 510 x10 6 km 2 Square Meters/ km 2 1,000,000 m 2 / km 2 Square Meters/ km 2 1,000,000 m 2 / km 2 Ice Age Area Net (km 2 )30 x 10 6 km 2 Ice Age Area Net (km 2 )30 x 10 6 km 2 Average Ice Thickness 1000 meters Average Ice Thickness 1000 meters Mass Ice Sheet30 x Metric Tons Mass Ice Sheet30 x Metric Tons Ocean Mass Present Day1,350 x Metric Tons Ocean Mass Present Day1,350 x Metric Tons CO2 Mass in Ocean (HCO 3 + )38,000 Gt CO2 Mass in Ocean (HCO 3 + )38,000 Gt Total Ice Volume3 x m 3 Total Ice Volume3 x m 3 CO 2 (0.15% in Ice) 100 ppmv CO 2 (0.15% in Ice) 100 ppmv Mass of CO2 in Glacier300 x Metric Tons Mass of CO2 in Glacier300 x Metric Tons Mass Carbon in CO 2 12/44 Mass Carbon in CO 2 12/44 Total Carbon in Glaciers82,000 GT Total Carbon in Glaciers82,000 GT Minimum Time to form Glacier2200 yrs (36.5 GT/year) Minimum Time to form Glacier2200 yrs (36.5 GT/year)

62 Where is the Missing Carbon? Not explained by Physical Properties of the Ocean Not explained by Physical Properties of the Ocean Ocean CO 2 is within 30 ppm of the Atmosphere Ocean CO 2 is within 30 ppm of the Atmosphere Not in the Forests Not in the Forests Must have gone into the Deep Ocean Must have gone into the Deep Ocean Where did the new CO 2 come from? Where did the new CO 2 come from?

63 PaleoClimate Change

64 Dry Lake in Death Valley

65 Nevada >5000 years ago

66 3 Million Years of Glacial Cycles

67 Recent Glaciations Lüthi, D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T.F. Stocker High-resolution carbon dioxide concentration record 650, ,000 years before present. Nature, Vol. 453, pp , 15 May doi: /nature06949

68 Milankovitch Cycles 23,000 years

69 Milankovitch Cycles 41,000 years

70 Milankovitch Cycles 100,000 years

71 0oC0oC Warmer Cooler 100ky50ky75ky25ky Maximum Rain Minimum Ice Maximum Snow Minimum Rain Maximum Ice Minimum SnowLast Glacial Max Now Temperature & Precipitation Cycle Cool & Dry Cool & Wet Warm & Dry Warm & Wet Warm & Dry Warm & Wet Cool & Wet Cool & Dry

72 Conclusions The Flora and Fauna of North America was very different 12,000 years ago The Flora and Fauna of North America was very different 12,000 years ago There are several incomplete theories that explain the extinction of Megafauna There are several incomplete theories that explain the extinction of Megafauna Global Deglaciation is linked to this extinction event Global Deglaciation is linked to this extinction event C4 Plants dominated C3 plants during low CO2 may be the “smoking gun” C4 Plants dominated C3 plants during low CO2 may be the “smoking gun” Glaciers are dynamic entities, that require precipitation to accumulate ice and heat to ablate. Glaciers are dynamic entities, that require precipitation to accumulate ice and heat to ablate. Global Glaciation Cycles are a result of small long term cycles in the Earth’s orbit Global Glaciation Cycles are a result of small long term cycles in the Earth’s orbit The Pleistocene Ice Age cycles are the greatest Global Catastrophe that has occurred since the Dinosaurs went extinct The Pleistocene Ice Age cycles are the greatest Global Catastrophe that has occurred since the Dinosaurs went extinct

73 Abrupt Climate Change Another answer to Global Warming


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