Coastal Investigations
How long is a coastline? It depends how closely you look.
A living account of journeys and discoveries into the coastline paradox — and how technology, big data, and AI can help us understand and value coastlines where it matters.
A single number can’t capture the world’s coastline — its length grows the closer you look. This “coastline paradox” demonstrates how natural complexity resists simple measurement. Fractals — patterns that repeat at ever smaller scales — help explain this infinite detail. Once a curiosity of geography and math, it’s now highly relevant: in an era of satellites, AI, and big data, how we measure shapes what we know. From climate adaptation to digital mapping, the coastal paradox challenges us to rethink precision, scale, and decision-making.
Coastline estimates for Norway vary dramatically from 2,650 km to over 100,000 km, depending on whether its fjords and islands are included and the detail of measurement.
Saint Martin / Sint Maarten is the smallest inhabited island divided between two nations in the world, with an area of around 60 km². Located in the Caribbean, legend has it that a coastal walking contest achieved this. A Frenchman and a Dutchman were each instructed to start from the same point on the coast, walk in opposite directions around the island, and wherever they met would define the border. The French supposedly covered more ground — some say because he walked faster, others because the Dutchman stopped for a drink of Dutch gin along the way. Or perhaps the Dutchman was more meticulous about walking the exact outline of the coast…? As a result, the French ended up with the larger northern portion (about 60%), and the Dutch with the southern 40%.
So, in view of the coastal paradox, where to zoom in, or zoom out, to gain relevant investigations?
This site provides a living account of my own journeys and discoveries into coastal paradoxes. My personal fascination with coastlines started growing up on St. Martin / St. Maarten, the Friendly Island. This fascination has grown through living and travelling more widely across the globe.
My fascination with coastlines also extends to the hope about how technology opens opportunities, but may also involve risks. How is technology, including recent big data and AI revolutions, helping us to better understand and value coastlines where it matters? This site is my personal collection of investigations, insights, field notes, and experiments with issues that fit this remit.
The world’s coastlines, by one estimate
An interactive sunburst of coastline length by region and country. Explore it — then remember that every figure here would change with a different ruler.
Hover a segment for details. Click a region to zoom in; click the center to zoom back out. Figures are approximate — as the coastline paradox reminds us, every one of these numbers depends on the length of the ruler.