No Evidence for Milankovitch Cycle Influence on Abyssal Hills at Intermediate, Fast, and Superfast Spreading Rates

Abstract

A recent hypothesis contends that abyssal hill topography is linked to sea level periodicities expressed by Milankovitch cycles, predicting that abyssal hill elevation is correlated to crustal age. We test this prediction by stacking (averaging) bathymetry as a function of age to enhance age-dependent signal while suppressing random (primarily faulted) components. Stacking is applied to bathymetry data flanking intermediate, fast, and superfast spreading ridges. Revised digital crustal age models were generated in these regions using a recent compilation of reliable magnetic anomaly identifications, with inferred temporal uncertainty of ~0.01 my. We utilize statistical properties of abyssal hills to predict the variability of the age-stack under the null hypothesis that abyssal hills are random with respect to crustal age; the age-stacked profile is significantly different from zero only if it exceeds this expected variability by a large margin. Our results do not support the presence of Milankovitch-driven signals in abyssal hill topography.