Also.
I think that the skull and cross bones looks VERy much like a map of devastating earthquakes that have struck acording to the work map.
Give me a second here to explain myself.
Imagine that the skulls face represents a map and where each of the numbers is, is a place of destruction on the map;
Imagine that the place where the !st number 3 is where the Japan earthquake struck. Superimpose this place/marked number onto a map. Then imagine going across the skulls face is the Pacific ocean. The spot above the skulls other eye would be the Pacific Northwest in the United States. Then the last 3 on the bottom right corner of the skull is about where the Christ Church earthquake struck, no??????
Just something interesting to consider.