Overburden Thickness Ice Exposure
< 4 m in 2016, > 4 m in 2017 & 2018 2 Ice in 2016: no ice in 2017 & 2018 2
< 4 m in 2016 & 2017: > 4 m in 2018 1.5 Ice in 2016 & 2017: not in 2018 1.5
Remains the same 1 Remains the same 1
> 4 m in 2016 & 2017: < 4 m in 2018 0.75 No ice in 2016 & 2017: ice in 2018 0.75
> 4 m in 2016: < 4 m in 2017 and 2018 0.5 No ice in 2016: ice in 2017 & 2018 0.5