The glacier tourism industry could be under threat because of ongoing glacial retreat.
Canterbury University geography lecturer Heather Purdie has been monitoring Fox Glacier's retreat since 2005, focusing on the glacier's physical changes and how they affect tourist access and safety.
Dr Purdie says steepening ice slopes and rockfall hazards are just some of the challenges facing guided walks at both the Fox and Franz Josef glaciers.
A digital model is being made so that safe routes for guided walks can be tested.
Dr Purdie said glaciers regularly advance and retreat about every decade, but climate change is reducing the growth period.