[synctext]

PNAS paper: http://www.pnas.org/content/early/2014/04/16/1321441111.abst...

Yale promo: temperatures in parts of Antarctica reached as high as 17 degrees Celsius (63F) during the Eocene, with an average of 14 degrees Celsius (57F) — similar to the average annual temperature off the coast of California today.

PNAS abstract: Here, we present multiproxy data from Seymour Island, near the Antarctic Peninsula, that provides well-constrained evidence for annual SSTs of 10–17 °C (1σ SD) during the middle and late Eocene.

[JoeAltmaier]

Where was Antarctica during the Eocene? Was it then parked over the South Pole?

[tokenadult]

A Google search "Eocene epoch continents" brings up pages suggesting Antarctica's location then was similar to its location now. Thank you for asking that interesting question, as I remembered that in earlier deep geologic time, Antarctica was much nearer to the equator.

[edj]

It sounds like Australia's geographical relationship to Antarctica at the beginning of the Eocene contributed to Antarctica's temperate climate at the time. From Wikipedia[1}:

At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents mixed with colder Antarctic waters, distributing the heat around the planet and keeping global temperatures high, but when Australia split from the southern continent around 45 Ma, the warm equatorial currents were routed away from Antarctica. An isolated cold water channel developed between the two continents. The Antarctic region cooled down, and the ocean surrounding Antarctica began to freeze, sending cold water and icefloes north, reinforcing the cooling.

1: https://en.wikipedia.org/wiki/Eocene#Palaeogeography

[phaemon]

Yes. Apparently Earth looked something like:

http://www.nature.nps.gov/geology/usgsnps/pltec/sc50ma.html