By flying transects over the ice, a picture of its thickness emerges.

BBC: Arctic ice melting at 'amazing' speed, scientists find

With 102 holes drilled so far, hundreds of measurements have been made of ice thickness and snow cover over the 243km covered to date.

BBC: Arctic team: 'London, we have a problem'

Calabresi says his next step will be to look at changes in the fiber layer thickness in 100 patients over a period of three years.

CNN: Can an eye exam detect multiple sclerosis?

Firstly, the two wells are monstrously deep well, with over 3, 000 feet net shale thickness.

FORBES: UK Shale Gas: How Deep Is It?