Active sutures at 450 Ma

Tropical suture length is not a measurement. It is the output of three choices, all of which the source dataset enumerates and one of which got published. Move them.

8000 Ma

Reading the chart

Each faint line is one combination of the choices above — a real setting somebody could defend, not a quantile. The bright line is the combination currently set. Hover a line to name it, click to snap the controls to it. The shaded band beneath is measured, and is drawn differently for that reason.

What the reconstruction lost

Plate IDs were assigned by the source against the models it used. Where a plate's rotation chain does not reach a suture's own age, the suture is dropped or its window clamped rather than drawn at its present-day position — which is what asking for a rotation outside a plate's defined range silently returns. The two models lose different sutures, so part of any gap between their curves in deep time is model coverage, not geology.

Sources

Sutures, activity intervals, plate-ID assignments and glacial extent (0–525 Ma): Macdonald, Swanson-Hysell, Park, Lisiecki & Jagoutz (2019), Science 364, 181–184, as published in the authors' Arc_Continent_Analysis repository. Latitude bands ±10/15/20/40° are that dataset's own columns.

Glaciations older than the record above (717–580 Ma): Hoffman et al. (2017), Science Advances 3, e1600983, Table 1; Gaskiers from Pu et al. (2016), Geology 44, 955–958. These are a different quantity, not a continuation — dated interval brackets, not a continuous ice-margin latitude — composed alongside the extent curve rather than replacing it. 580–525 Ma is covered by neither and is drawn as no data.

Reconstructions: Merdith et al. (2021); Torsvik & Cocks (2017), CEED, both as gprm distributes it and as the source's own repository ships it (Swanson-Hysell & Macdonald + Domeier 2018) — the two disagree by 13° of Laurentian latitude at 445 Ma. Plate IDs are the source's own — its attribute table carries one column per frame (PLATEID1, PLATEID_CE) and this page assigns none. Which column belongs to which model was established by test, not by the column names. Selecting a model swaps its continents, boundaries and sutures together; only Merdith has topologies, so plate boundaries draw for that model alone. Continent polygons include the submerged shelf, so they run wider than a coastline.

Every dataset above is tracked family-wide, alongside genuine alternatives and the choices made turning a source into a curve, in registry.json — fetched from the StoryMaps family registry at deploy time rather than decided fresh by this page.