When such an eruption is continued over a longer time span, the water in the end does not reach the vent(s) any more and lava begins to flow.

[6] Ice thickness and more exact time of eruption in the case of Keilir are not known, just that it took place during the Pleistocene (Weichselian).

The Antarctic cone did lie under a polar ice sheet and not a temperate glacier as was the case with Keilir.

And the tuff cone from Victoria Land, Antarctica, is placed next to known granitic plutonic complexes and seems to be a parasitic cone of a stratovolcano, whereas Keilir is located adjacent to presently active volcanic systems and looks as if it were placed on top of the shield volcano Þráinskjöldur, though the last one is younger than the subglacial formation.

[7] An excellent view over a big part of Reykjanes Peninsula and Faxaflói is to be expected from the top in good weather.