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What do we know about the history of climate during the Quaternary?

What do we know about the history of climate during the Quaternary?. DSDP-1968 Glomar Challenger ODP-1985 JOIDES Resolution IODP-2003 Chikyu. Deep Sea Drilling. Chikyu. + O 18 /O 16 -. CaCO 3. Layer by layer sampling of plankton reveals oxygen isotope record.

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What do we know about the history of climate during the Quaternary?

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  1. What do we know about the history of climate during the Quaternary?

  2. DSDP-1968 Glomar Challenger ODP-1985 JOIDES Resolution IODP-2003 Chikyu Deep Sea Drilling Chikyu

  3. + O18/O16 - CaCO3 Layer by layer sampling of plankton reveals oxygen isotope record

  4. Ice stores O16 so that oceans are O16 depleted in an ice age

  5. The record for the last 730,000 years indicates that eight major glacial and interglacial events or climatic cycles of about 100,000 years' duration occurred during this interval. Similar cycles but of greater frequency and lesser magnitude continue back to the late Pliocene.

  6. Isotopic record from the North Atlantic suggests the first major glaciation in that region occurred about 2,400,000 years ago, early in the Pleistocene. It also suggests that the first glaciation large enough to have covered extensive areas of North America and Eurasia occurred about 850,000 years ago during oxygen isotope stage 22.

  7. Largest glaciations took place in stages 2, 6, 12, and 16; interglacials with the least global ice, and thus the warmest, may be stages 1, 5, 9, and 11. Last interglaciation was during all of stage 5 or just substage 5e, depending on location; last glaciation took place during stages 4, 3, and 2; and the current interglaciation falls during stage 1.

  8. How will a glaciation affect Pacific Islands? How will an interglaciation affect Pacific Islands?

  9. 234U/230ThU t1/2 245,000 Th t1/2 75,000At equilibrium, the number of thorium-230 decays per year within a sample is equal to the number of uranium-234 decays per year in the same sample. Uranium is soluble in water, Th is not, hence U may be taken up by precipitating solids such as coral, etc. Corals and others may behave as open system due to groundwater, roots, soil, recrystallization. Ratio of 234U/238U can reveal contamination.

  10. Oxygen isotope record of climate cycles 0.25 0.2 0.15 0.1 0.05 0 2.5 2.0 1.5 1.0 0.5 0.3 0.1 0 Saw tooth pattern: Slow ice sheet build-up, then rapid ice sheet collapse 120-140 m sea-level fluctuations

  11. 0.25 0.2 0.15 0.1 0.05 0 2.5 2.0 1.5 1.0 0.5 0.3 0.1 0

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