"In April 1970 a Scott Polar Research Institute (S.P.R.I.) MK II 35 MHz radio echo sounder was used to obtain depth and velocity measurements on Meighen Ice Cap, Baffin Island (lat. 80° N, long. 99° W) and Barnes Ice Cap, Baffin Island (lat. 70° N, long. 72° W)"--Introduction, page 1.