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Phanerozoic 550 Ma
Cenozoic 65 Ma
Late Cretaceous Southern Ocean
Not shown – plateaus in the southern Indian Ocean
Zachos Cenozoic record
Linear, non-linear, and threshold responses
Fractal strange attractors
Eocene Thermal Maximum
Eocene circulation
Low-latitude east to west circulation, similar to Cretaceous
Southern Ocean gateways
STF = Subtropical Front AAPF = Antarctic Polar Front AAD = Antarctic Divergence SAF = Subantarctic Front
Late Cenozoic sea level
Oligocene ice growth
One of the largest, most rapid drops in sea level during the Phanerozoic
Truly cold deep water
Bottom temp’s may have dropped 4-5°C
Topography of Antarctica without ice
Crossing a threshold – Rapid growth of the Antarctic Ice Sheet
Iceland-Faeroe Ridge
Initial connection with the Arctic Ocean in the Paleocene
Spill-over in late Eocene cools deep water in Atlantic
Finally open to deep water in late Miocene
NADW site map
Australia separates from Antarctica
Contributed to late Eocene cooling of the deep ocean
Major cause of thermal isolation of Antarctica in Oligocene
Oligocene circulation
The only remaining barrier is the Drake Passage
Progressive blockage of the Indonesian Seaway
Miocene Southern Ocean
Deep-water flow betweenAustralia-New Zealand and Antarctica
Surface-water flow through Drake Passage initiated in Oligocene
Now deep flow begins
Late Miocene – the Messinian salinity crisis
High topography Western North America
Orographic effect
India collides
Tibetan Plateau
Northern Indian Ocean
90 East Ridge
Chagos- Laccadive Plateau
Himalayas and monsoons
Monsoons
Monsoons and Indian Ocean circulation
Looking into the Himalayas
Sediment flux to ocean basins – 40 Ma
Strontium isotopes 400 Ma
Pliocene 5.5 Ma
Closure of Panama – Pliocene
Table SL fall 80 Ma
Raymo 5 Ma record
Raymo 41-ky to 100-ky cycles
Mid to Late Pleistocene 450 ka
Holocene temperature variations
Late Holocene 1000 years
Instrumental records 150 years
1965-1975 cooling
1995-2004 warming
…to be continued
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