The 'heartbeat' of Earth's ice ages is way more complicated than we thought, featuring weird 'forbidden' patterns that shouldn't exist.
Textbooks usually say ice ages happen every 41,000 or 100,000 years. This research found hidden, middle-ground cycles that prove Earth's climate responds to planetary orbits in ways we previously thought were impossible.
Beyond the 100-kyr and 41-kyr dichotomy: ~76-kyr and ~52-kyr signals and forbidden periodicities
EarthArXiv · 10.31223/X5419D
While the Mid-Pleistocene Transition (MPT) is often described as a shift from 41-kyr to $\sim$100-kyr glacial cycles, this binary perspective fails to capture the nuanced spectral evolution of Quaternary climate. Applying wavelet-based spectral analysis to benthic d18O records, we identify previously underappreciated signals－~52 kyr before 1.2 Ma and ~76 kyr thereafter－marking the MPT's onset. Insolation analysis reveals these timescales primarily correspond to integer multiples (n) of the local