FIGURE 3. Ice-surface elevations at instantaneous times during the transition from 'Greenhouse' to 'Icehouse' conditions in our nominal 10-Myr simulation (Fig. 2a, red curve).

From the following article:

Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2

Robert M. DeConto and David Pollard

Nature 421, 245-249(16 January 2003)



a, At year 4,700,000, three small, isolated ice caps exist on the highest elevations of Dronning Maud Land and the Gamburtsev and Transantarctic mountains, fluctuating only slightly with orbital variations. b, At year 5,200,000 as CO2 declines below 3 times preindustrial atmospheric level, a small ice-sheet threshold21,22 has been reached for the Gamburtsev ice cap, which greatly expands in volume. c, At year 5,800,000, further decline of CO2 allows the Gamburtsev and Transantarctic ice caps to coalesce permanently, buttressing each other to form a much larger central ice sheet. This central ice cap makes repeated, but temporary, contact with the Dronning Maud Land ice cap during orbital periods with minimal summer insolation. d, By year 6,000,000, a further jump in volume occurs as the Dronning Maud ice cap permanently coalesces with the rest of the ice mass, forming a continental-scale East Antarctic Ice Sheet with two main spreading centres and major discharges down the Lambert Graben and other bedrock troughs to Prydz Bay and the Wilkes and Aurora basins.