This visualization animates contour lines of volcano elevation data, smoothly interpolating between threshold boundaries to create a flowing, morphing effect over a geographic projection. The contours are generated using `d3.contours` from a grid of elevation values in `volcano.json`, projected with `d3.geoNaturalEarth1` and rendered as SVG paths via `d3.geoPath`. A sequential plasma color scale encodes elevation values, while an infinite loop transitions path shapes and fills every 200 milliseconds using `d3.transition`. The animation cycles through paired thresholds, creating continuous, fluid distortions of the terrain.