Extended Data Figure 4: Mapping elevation changes during LIAmax to 1978–87.
From: Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900
a, Type 1 points are placed at the trimline or lateral moraine marking the LIAmax position and at the 1978–87 ice surface perpendicular to the flow direction, and as we assume that the cross-section profile of the glacier is the same during the LIAmax and 1978–87 then the vertical difference dh is the thinning at this location. This approach is the same as used by ref. 9. b, For Type 2 points we assume that the longitudinal shape of the glacier is the same during the LIAmax as in 1978–87. Points are placed at the LIAmax margin and at the 1978–87 margin, and assuming a longitudinal profile that does not change over time, the distance dL is used to find the vertical difference between the 1978–87 point and a point on the glacier at a distance of dL following the same flowline. Points for glaciers receding on steep slopes have been discarded.
