Fig. 2: Vertical δ18O profiles showing the structure of the ocean at Cape Hatteras and Blake Outer Ridge during the mid-to-late Holocene and LGM.
From: Deeper and stronger North Atlantic Gyre during the Last Glacial Maximum
a, Mid-to-late Holocene. b, LGM. Filled coloured circles and squares represent the mean value for each depth at Cape Hatteras and Blake Outer Ridge, respectively (individual monospecific batch data are shown in Extended Data Fig. 4). Associated error bars are ±2 standard errors (standard error = σ/√n, in which σ is the multispecies replicate error at either Cape Hatteras or Blake Outer Ridge across both time periods and n is the number of species analysed at each depth). Open symbols correspond to published δ18O from proximal sites in the Northwest Atlantic >35° N (blue circles) and <35° N (red squares; Methods and Source Data)7,28,47,48 and dashed coloured lines are smoothing splines through both new and published data >35° N (blue) and <35° N (red). All δ18O are reported relative to the VPDB standard. The dashed horizontal black line in each panel denotes the changepoint at which both profiles first converge within error, which we interpret as the maximum depth of the STG. This was done through application of a piecewise linear regression model with one changepoint for all Blake Outer Ridge data from >0.6 km.
