Algorithm for the numerical assessment of the conjecture of a subglacial lake at Svalbard, Spitzbergen

The melting of glaciers coming with climate change threatens the heritage of the last glaciation of Europe likely contained in subglacial lakes in Greenland and Svalbard. This aspect urges specialists to focus their studies (theoretical, numerical and on-field) on such fascinating objects. Along this line we have built up a numerical procedure for validating the conjecture of the existence of a subglacial lake beneath the Amundsenisen Plateau at South-Spitzbergen, Svalbard. In this work we describe the algorithm and significant representative results of the related numerical test. The conjecture followed the Ground Penetrating Radar measurements of that area exhibiting several flat signal spots, sign of the presence of a body of water. Actually, numerical simulation results appear in support to the decision of drilling operations above the presumed ice/water front where subglacial lake water bio-chemicals might be traceable. The time dependent mathematical model, structuring the numerical algorithm, includes the description of dynamics and thermodynamics of the icefield and of the subglacial lake, with heat exchange and liquid/solid phase change mechanisms at the interface. Critical modeling choices and confidence in the algorithm are granted by the numerical results of the sensitivity analysis versus the contribution of ice water content, of firn and snow layers at top of the icefield and versus the approximation of ice sliding on bedrock, that have been issued in previous recent works also including successful comparison with measured quantities.