After >500 Ma of absence, major Northern Hemisphere glaciations appeared during the Plio-Pleistocene, with Greenland leading other northern areas. Here, we propose that three major solid-Earth processes underpinned build-up of the Greenland ice-sheet. First, a mantle-plume pulse, responsible for the North Atlantic Igneous Province at ~60 Ma, regionally thinned the lithosphere. Younger plume pulses led to uplift, which accelerated at ~5 Ma, lifting the parts of the East Greenland margin closest to Iceland to elevations of more than 3 km above sea level. Second, plate-tectonic reconstruction shows a ~6° northward component of Greenland motion relative to the mantle since ~60 Ma. Third, a concurrent northward rotation of the entire mantle and crust towards the pole, dubbed True Polar Wander (TPW), contributed an additional ~12° change in latitude. These global geodynamic processes preconditioned Greenland to sustain long-term glaciation, emphasizing the role of solid-Earth processes in driving long-term global climatic transitions.
- Programområde 3: Energiressourcer