Dear Authors,

this manuscript triggered very interesting discussions as to the robustness of the new proposed hydro-thermodynamic feedback, and as to whether this adds to the current state of knowledge on surge mechanisms for Svalbard Glaciers, and whether this can be extended to other polar ice sheets. The initial manuscript needed thorough review, with both reviewers calling for major modifications. The work carried out on the manuscript however takes care of all the concerns raised, and in my opinion takes better advantage of the new datasets collected (extended time series from the initial 2 years in Dunse et al., 2012), both in terms of GPS, but also in terms of new summer velocity maps in summer, to propose a complementary mechanism that now introduces the impact of summer melt on a typical surge mechanism. The new mechanism is I believe sufficiently well documented and analysed to be published. I commend the authors for the thorough rework of the manuscript, and I am pushing it or final publications as is.

Best regards,

Eric Larour