fresh block
A map visualizes multiple voyages as colored, animated routes across a Mercator projection, with each year's set of journeys shown as dimmed paths and red markers moving along them, while green and red text labels sort voyages by year and individual trip. Clicking a year toggles its paths' opacity, and clicking a voyage label triggers a transition on the corresponding path marker. The visualization uses D3 v4's `d3.geoMercator`, `d3.geoPath`, `d3.line` with `d3.curveCatmullRom`, `d3.nest`, `d3.queue`, and `d3.csv`, reading voyage data from `multipleVoyages4.csv` to render SVG paths, circles, and text with fading encodings.