Lee was a hard-luck pitcher last year, going 6-9 despite a 3.16 ERA. He nearly recorded his first complete game since Sept. 15, 2011.

WSJ: Gee tagged for 3 HRs, Phillies beat Mets 8-3

The time taken for the waves to complete this journey is recorded, and it is a fairly straightforward calculation to work out the height of the ice above sea level.

BBC: Arctic ice thickness 'plummets'

The International Maritime Organisation (IMO), which provides regulations for cruise ships, does not keep complete records of marine casualties but recorded fewer than 300 incidents since 2000, while the independent website CruiseJunkie, run by sociology professor Ross Klein of Memorial University Newfoundland, has published reports of 644 incidents in the same period.

BBC: What is the safest mode of travel?