To make your map you will need to find the thickness of the glacier ice and any water associated both on the surface and in the interior (fissures, subsurface channels, or sub glacier pooling). Ideally you will need a time series to show how the glacier flows over time and changes seasonally. To fully map all the changes over time will require serious planning, use of many instruments, and processing huge amounts of data. For ice thickness, gridded flights using radar can give the thickness of the ice and the morphology of the glacier bed. It also helps to know the geology of what the glacier is moving over. The radar data will show ice layers within the glacier and any water associated on the surface and/or under. This will be volumetric in voxel form. For even finer resolution traditional LIDAR can provide more glacial surface detail also with gridded instrumented flights. For details of depth of water (lakes) on the surface of the glacier non-traditional LIDAR using a green laser can be used also using gridded flights over the glacier lakes to map bathymetry. For finer details on the surface of the glacier that are not picked up from traditional LIDAR use of photogrammetry can be accomplished by using gridded flights and high resolution cameras on drones or a plane. All of the methods mentioned will then give you 3D temporal data that can be input and used with flow modeling software. The most commonly used software for simulating glacier ice flow is called "OGGM" (Open Global Glacier Model), which is an open-source. I am fairly sure other software exists that could also be used. Last is taking into account weather changes over time considering global warming. Hope this helps.