Time-series analysis focused on the Eocene-Oligocene transition (EOT) showing the switch from obliquity to precession-515

Contexts in source publication

Context 1

... scale for the power axis (e.g., Fig. 3). To study the evolution of cycles throughout the record, we used evolutive harmonic analysis (EHA) with a function computing a running periodogram of a uniformly sampled (dx=10 cm) time series using FFTs of zero-padded segments, and normalized to the highest amplitudes (e.g., Kodama and Hinnov, 2014; Fig. ...

Context 2

... extract target cycles, we used conjointly bandpass gaussian filtering ( Paillard et al., 1996) and the smoothing technique 155 based on the weighted average LOWESS method (e.g., Fig. 3). Finally, to convert the depth into the time domain, we used the 405 kyr stable eccentricity period because it is well expressed along the whole core (Figs. 2 and S8), and its phase is very stable ( Laskar et al., 2004Laskar et al., , 2011). We anchored the NGR record at previously proposed ages of EOB. ...

Context 3

... inspection of the NGR variations points to prominent obliquity-scale cycles (with very weak or no precession cycles) 490 occurring in the upper part of Chron C13r, within the 405 kyr cycle no. 85 (Fig. 8). The dominance of the obliquity starts ca. expressed, and the eccentricity is stronger than the obliquity. The time span between the onset (beginning) of obliquitydominant cycles and the EOT-1 equivalent level (Sect. 5.2) is 0.280 Myr, which is in the same order than the 0.3 Myr proposed by Katz et al. (2008) between the EOT precursor ...

Context 4

... increased seawater cell convection in relation with the formation of deep waters (Fig. 7B, Kaminski and Ortiz, 2014; onset of regime 3 in Coxall et al., 2018). This abrupt biotic turnover shift is ∼630 kyr older than the EOB (Coxall et al., 2018 their Fig. 3F). In the continental CDB1 core, obliquity started to dominate ∼650 kyr before the EOB (Fig. 8). This remarkably coincident timing leads us to suggest the obliquity-dominated CDB1 interval support the NADW formation hypothesis. This is substantiated by (1) the CDB1 location directly affected by NADW, (2) the NADW sensitivity to obliquity and (3) the 535 expected westerly moisture source of CDB1 governed by the NADW (e.g., Abelson ...