6.3. Ice dynamics

The dynamics (force balance) of grounded ice can be chosen in the run-specs header by the parameter DYNAMICS:

• 0: Ice flow velocity set to zero everywhere (static ice).

• 1: Shallow-ice approximation (SIA) (e.g., Greve and Blatter [30]).

• 2: Hybrid shallow-ice–shelfy-stream (SIA/SStA) dynamics (Bernales et al. [5, 6]).

• 3: DIVA (depth-integrated viscosity approximation) dynamics (Goldberg [20], Lipscomb et al. [47], Grandadam [21]).

The parameter MARGIN controls how the grounded ice can extend into the sea:

• 1: Ice extent strictly restricted to land area (“hydrophobic mode”).

• 2: Formation of marine ice possible.

• 3: Formation of marine ice and ice shelves possible.

In case of MARGIN = 3, ice shelves (floating ice) are included and modelled by the shallow-shelf approximation (SSA; e.g., Greve and Blatter [30]).

The detailed settings are controlled by additional parameters as described in the run-specs headers.