At http://phys.org/print297525077.html … the West Antarctic ice sheet existed 20 million years earlier than previously thought runs the headline but how do scientists arrive at his kind of bald statement?
The West Antarctic ice sheet is basically the peninsular that sticks out like a sore thumb at the top of the Antarctic subcontinent which for some reason is defined as the East Antarctic ice sheet. The peninsular is below sea level – or very nearly so. It consists of segments with channels of ice and water separating the different pieces. However, covered in ice it has the appearance of a single land formation and as it has a different latitude to the rest of Antarctica it has sometimes been ice free when the bigger part was still buried in ice. This is the mainstream view. Earlier studies, using computer simulations, were unable to produce the amount of ice that geological records suggest existed at the time because they were factoring in the wrong information. So it is alleged. However, by raising the profile of West Antarctica, literally raising it out of the sea, enabled computer simulation to cover it with ice 34 million years ago.
The research also involves ice at the northern hemisphere – where it really should not be if the consensus theory is right, at the transition between what is seen as a greenhouse warmed world and the first ruffling of a colder climate.