Styling hypsometry and bathymetry for a different perspective on Earth’s contours
By: Madison Draper
Earth isn’t smooth like a globe or flat like a map, it’s an ever-changing and beautifully contoured geoid. The Bubble map style highlights these contours. Focusing the map on hypsometry and bathymetry — the measurement of land elevation relative to average sea level, and the measure of depth in water features relative to the average sea level — heightens the natural features and geometries. With no labels, roads, boundaries and other human-created features, Bubble provides a different perspective on the landscape itself.
The Design: Color
With only 12 layers, this a minimal style, but by no means is this a simple style. The inspiration for the hypsometric palette was based off the radiant color swirls of a bubble. The paths of mountain ranges contort in similar, abstract ways.
Bubble uses an elaborate palette to highlight changes within a single tileset. To do this in Mapbox Studio, I added the Mapbox Terrain V2 tileset’s contour layer and styled across the data range. Using a cubic bezier curve for the rate of change, the colors blend into one another as elevation climbs.
The terrain data is styled with contour fills painted over the Terrain RGB layer. The contour colors blend into each other to create a smooth transition between colors. Terrain RGB is styled with a light pink highlight and a nearly-black pink shadow to amplify the 3D terrain.
The bathymetric palette uses different hues and opacities to accent the underwater elevations to a visible coherence. Instead of a linear progression, the lightest blues are exponentially lighter to mimic older maps that keep coastline areas clear for port and label legibility. This light blue presents a cleaner, less distracting canvas for the hypsometric data than a darker blue would.
Unlike the terrain data, each step in the bathymetry data is set to a specific value. Because this data is more expansive, it makes the distinctions between each value clearer.
With Bubble’s two unique palettes, it’s like getting two map styles in one. Bathymetry data and styling is visible at all zoom levels. Because the hypsometric data is granular, I decided to increase the performance by beginning the hypsometric tinting at zoom level 9.
Broken down and abstracted from its geographic context, this chart below describes the relationship between the different colors.
Play with Bubble as a canvas for your next hike or data viz app. Its minimal canvas gives you the freedom to add only what you need and style it exactly as you want. Explore Bubble today by adding it to your account in Mapbox Studio. Share a screenshot of your favorite view or a new place you’ve found with #MapStyleMonday and we’ll reshare on twitter.
Bubble map style was originally published in Points of interest on Medium, where people are continuing the conversation by highlighting and responding to this story.