Fig. 1: Implementations of skeletons to preserve ocean gateways and land bridges.
From: Polar wander leads to large differences in past climate reconstructions
Ocean skeletons are shown in black, and land skeletons in red. a Present-day example demonstrating the implementation process. The top-left image shows the digital elevation map at the original resolution, while the top-right map shows the raw re-gridded elevations at the model resolution, which loses key ocean gateway information (e.g., the Panama Isthmus, where the thin land bridge has been lost). To rectify this, a skeleton algorithm traces contiguous ocean and land cells in the high-resolution elevation map (lower left), and the skeletons are imposed over the coarsened elevation map (lower right), restoring the Panama Isthmus. Note that a skeleton is incorrectly traced across the Strait of Gibraltar due to the insufficient resolution of the original elevation map to resolve the narrow strait. b Implementation of skeletons in the paleomagnetic23 (left column) and mantle21 (right column) reference frames at 210 Ma (top), 130 Ma (middle), and 40 Ma (bottom). Note that the skeleton from the paleomagnetic frame is rotated into the mantle frame, preserving its shape and ensuring that the same connections are maintained across both frames.
