New University of Melbourne research has revealed that ice ages over the last million years ended when the tilt angle of the Earth’s axis was approaching high values. During these times, longer and stronger summers melted the large Northern Hemisphere ice sheets, propelling the Earth’s climate into a warm ‘interglacial’ state, like the one we’ve experienced over the last 11,000 years. The team combined data from Italian stalagmites with information from ocean sediments drilled off the coast of Portugal. Using the latest techniques in radiometric dating, the international team determined the age of two terminations that occurred about 960,000 and 875,000 years ago. The ages suggest that the initiation of both terminations is more consistent with increases in Earth’s tilt angle.
— source University of Melbourne | Mar 13, 2020