Skip to main content
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1975 Oct;72(10):3825–3828. doi: 10.1073/pnas.72.10.3825

Stochastic models for the Earth's relief, the shape and the fractal dimension of the coastlines, and the number-area rule for islands

Benoit B Mandelbrot 1
PMCID: PMC433088  PMID: 16578734

Abstract

The degree of irregularity in oceanic coastlines and in vertical sections of the Earth, the distribution of the numbers of islands according to area, and the commonality of global shape between continents and islands, all suggest that the Earth's surface is statistically self-similar. The preferred parameter, one which increases with the degree of irregularity, is the fractal dimension, D, of the coastline; it is a fraction between 1 (limit of a smooth curve) and 2 (limit of a plane-filling curve). A rough Poisson-Brown stochastic model gives a good first approximation account of the relief, by assuming it to be created by superposing very many, very small cliffs, placed along straight faults and statistically independent. However, the relative area predicted for the largest islands is too small, and the irregularity predicted for the relief is excessive for most applications; so is indeed the value of the dimension, which is D = 1.5. Several higher approximation self-similar models are described. Any can be matched to the empirically observed D, and can link all the observations together, but the required self-similarity cannot yet be fully explained.

Keywords: mathematical geomorphology, Hausdorff dimensions, Brownian random surfaces, Gaussian processes

Full text

PDF
3825

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Mandelbrot B. How long is the coast of britain? Statistical self-similarity and fractional dimension. Science. 1967 May 5;156(3775):636–638. doi: 10.1126/science.156.3775.636. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES