seasoned explorers: "Gevurah is sometimes also called Din, and means 'strength' or 'judgment.' It is the fifth sefirah and represents the specific emotional energy that creates feelings...Gevurah lies on the left (feminine) side of the Tree of Life." The Kabbalah: kabbalah/terms.html

This far and no further: C. Ransmayr, The Terrors of Ice and Darkness. New York, 1991.

Not a nail but a whole plank: "'The strangers seek the Great Nail that was once driven into the ice of the north but has been lost. Whoever follows those who seek the Great Nail and finds it will have iron for his spears and axes.' (Eskimos of Annotoak, twentieth century.)" Ibid.

I looked behind: S. Berg. From, “Spirit Song.”

First International Polar Year: "Until that time, all of the probing in the Arctic was somewhat like a bunch of people working separately to assemble a jigsaw puzzle. Each person would collect some scattered pieces and try to fit them together. But no one shared information, and so nobody saw the big picture." A. C. Revkin, "First International Polar Year." The New York Times, 26 Feb 2007. International Polar Years were:1882-3, 1932-3, 1957-8. This IPY, 2007-8, will consist of over 200 scientists from more than 60 countries.

was not solid: J. Dore, Review of Ejnar Millelsen’s, Mirage in the Arctic. The Arctic Review.