Lithosphere formation at the ultraslow-spreading Gakkel Ridge: From reconnaissance seismicity studies towards passive seismology with under-ice ocean bottom seismometers

The third day of the 3P Arctic Conference & Exhibition is October 1. Session chairs Lawrence Lawver and Wilfired Jokat will welcome attendees and introduce session four speakers, who will be speaking on Central Arctic, Constraints on Arctic Plate Reconstructions and Russian Arctic. Vera Schlindwein, Alfred-Wegener-Institut, will be the fourth speaker to take the platform on Thursday.

Abstract: Lithosphere formation at the ultraslow-spreading Gakkel Ridge: From reconnaissance seismicity studies towards passive seismology with under-ice ocean bottom seismometers

The lithosphere that forms the seafloor of our planets oceans is remarkably uniform in all but the slowest opening ocean basins. The Arctic Ocean Basin and its equally remote counterpart in the stormy Southwest Indian Ocean grow as slowly as 6-15 mm/y. We undertook the endeavour to install seismometers on drifting sea ice, in the “Furious Fifties” of the Southern Ocean and under the ice cover of the Arctic Ocean to record the small earthquakes that accompany the birth of new ocean lithosphere. We discovered the deepest mid-ocean ridge earthquakes known that document a cold, thick lithosphere where water circulates to previously unbelievable depths. Our study indicates that the Arctic Ocean lithosphere grossly deviates from classic ocean lithosphere but we are only at the beginning of developing the technical means to explore its highly heterogeneous structure under the perennial Arctic sea ice cover.