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